FM - 55
Digital auDio Processor
Technical
Manual
600 Industrial Drive, New Bern, North Carolina 28562 (tel 252-638-7000 / fax 252-637-1285 )
FM - 55
Digital auDio Processor
Technical
Manual
Wheatstone Corporation
August 2014
ORSIS
Ultra-HigH resolUtion Processing
Wheatstone Digital Augio Processor Technical Manual
©2014 Wheatstone Corporation
FM-55 / Aug 2014
600 Industrial Drive
New Bern, North Carolina 28562
tel 252-638-7000 / fax 252-637-1285
Attention!Attention!
Federal Communications Commission (FCC) Compliance
Notice:
Radio Frequency Notice
NOTE: This equipment has been tested and found to comply with the
limits for a Class A digital device, pursuant to Part 15 of the FCC rules. These
limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This
equipment generates, uses, and can radiate radio frequency energy and, if
not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications. Operation of this equipment
in a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his own expense.
This is a Class A product. In a domestic environment,
this product may cause radio interference, in which case,
the user may be required to take appropriate measures.
This equipment must be installed and wired properly in order to assure
compliance with FCC regulations.
Caution!
Wheatstone could void the user's authority to operate this equipment.
Any modications not expressly approved in writing by
FM-55 / Sep 2014
Read Me!
ORSIS
Ultra-HigH resolUtion Processing
The History of Wheatstone Audio Processors
Introduced in 2005, the Vorsis product line evolved from Wheatstone’s return to
its original roots in audio processing. Having designed and integrated analog and
then, later, complex digital audio processing into our radio and television consoles
and control surfaces, Wheatstone was perfectly poised to address the challenges of
combining very high audio quality with competitive on air loudness.
Wheatstone audio processors are built to the same exacting standards as all
Wheatstone products. Research and development, manufacturing, testing, and qual‑
ity control for the line of audio processors are all accomplished within Wheatstone’s
large state‑of‑the‑art facility located in New Bern, North Carolina. Keeping everything
under one roof allows Wheatstone to have control over every facet of production
and ensures that our costumers receive products of the highest possible quality and
reliability. Staying true to “Made in the USA,” Wheatstone does not utilize offshore
manufacturing.
A dozen experts with deep experience in Digital Signal Processing, broadcast
audio and other engineering disciplines comprise our design team. Led by audio
processing expert and broadcast engineering veteran Jeff Keith, the team combines
their talents to design and build audio processors that achieve the highest standards
of on ‑air sound quality.
In its short history Wheatstone Processing has already invented many new and
unique audio processing algorithms – algorithms that push audio processor perfor‑
mance to new and higher levels. Wheatstone was the rst to develop an intelligent,
“program density aware” AGC (2007 ‑ Sweet Spot Technology, or SST). We were
also the rst to employ the science of human psychoacoustics in the design of a mul‑
tiband limiter (2005, our acclaimed 31‑band limiter). In addition, our well‑regarded
Bass Management systems solve the bass intermodulation problems that plague other
brands of audio processors when pushed for competitive loudness.
Each Wheatstone Processing product comes with its own Windows® software‑based
intuitive Graphical User Interface for control of the processor. Carefully tuned factory
presets ensure that our audio processors can be placed into use quickly and easily in
any size market with a minimum of effort.
FM-55 / Aug 2014
Int r od u ct I on - 1
CONTENTS
FM-55 Technical Manual
Table of Contents
Chapter 1 - General Information
Introduction ....................................................................................1-2
FM-55 Feature Overview ...............................................................1-3
Rack Mounting ............................................................................... 1-3
FM-55 Installation Tips ...............................................................................................1-5
Grounding ...............................................................................................................1-5
Surge Protection .....................................................................................................1-5
UPS/Power Conditioning ........................................................................................1-5
Analog Audio Input Connections ............................................................................1-5
Analog Audio Output Connections .........................................................................1-6
Digital Audio/baseband192 Connections ................................................................1-6
Where to Install the FM-55 .........................................................................................1-7
Digital STL ..............................................................................................................1-7
Analog Left/Right STL ............................................................................................1-8
Composite Analog STL ...........................................................................................1-8
Analog Phone Lines ...............................................................................................1-8
Where Should Pre-Emphasis Go? .........................................................................1-9
Ratings Encoders ...................................................................................................1-9
AC Power Considerations ............................................................1-9
Rear Panel Connections ..............................................................1-10
Audio Inputs ...............................................................................................................1-10
Analog In ................................................................................................................1-11
AES In ....................................................................................................................1-11
SCA In ....................................................................................................................1-11
FM Audio Outputs ......................................................................................................1-11
Analog Out ..............................................................................................................1-11
AES/baseband192 Out ...........................................................................................1-11
TX Out ....................................................................................................................1-12
Headphone Monitoring ..............................................................................................1-12
Network Connection ..................................................................................................1-12
Ethernet RJ-45 .......................................................................................................1-12
Typical Straight-Through Cable ..............................................................................1-12
Typical Crossover Cable ........................................................................................1-13
General Purpose Interface (GPIO) ............................................................................1-14
GPIO RJ-45 ............................................................................................................1-15
Processing Presets ....................................................................................................1-15
FM-55 Input/Output Connections Drawing ................................................................1-17
FM-55 / Aug 2014
page Contents – 1
CONTENTS
Chapter 2 - FM-55 Front Panel
Meters ............................................................................................. 2-2
Input Level Meters ......................................................................................................2-2
AGC Meters ................................................................................................................2-2
Limiter Meters .............................................................................................................2-3
Output Meters .............................................................................................................2-3
OLED Display ................................................................................. 2-3
Headphone .................................................................................................................2-5
Source Selection .....................................................................................................2-5
Headphone Volume .................................................................................................2-5
Presets .......................................................................................................................2-5
Input............................................................................................................................2-5
Input Source ............................................................................................................2-5
Input Gain Adjustment .............................................................................................2-6
Pre-Emphasis .............................................................................................................2-6
Sound .........................................................................................................................2-6
Texture ....................................................................................................................2-6
EQ ...........................................................................................................................2-7
Save ........................................................................................................................2-7
A Note About The Front Panel Sound Adjustments ................................................2-7
Output .........................................................................................................................2-8
Network ......................................................................................................................2-9
Changing The Network Settings .............................................................................2-9
Leading Zeroes ........................................................................................................2-9
Default IP Address ...................................................................................................2-9
Vesions .......................................................................................................................2-9
Access .......................................................................................................................2-10
Chapter 3 - FM-55 PC GUI
Getting Started ...............................................................................3-4
Connecting With the GUI ..............................................................3-5
Configuring the GUI ......................................................................3-5
Connecting Directly Without a LAN ............................................................................3-5
The FM-55 and Internet Security Concerns ...............................................................3-6
About DHCP and the FM-55 .......................................................................................3-6
The FM-55 Network Protocols and Ports Used ..........................................................3-6
Using the FM-55 GUI .....................................................................3-7
Dynamic Displays Region ...........................................................................................3-8
Frequency-Domain Graph .......................................................................................3-8
Managing the Blue Dots - Tutorial ...........................................................................3-8
Control Area Region ..................................................................................................3-10
Input Menu ..............................................................................................................3-11
Input Source .......................................................................................................3-11
Input Signal Presence ........................................................................................3-11
Input Failsafe ......................................................................................................3-12
Analog Input Gain ...............................................................................................3-12
Digital Input Gain ................................................................................................3-12
L/R Balance ........................................................................................................3-12
Phase Rotator .....................................................................................................3-12
FM-55 / Aug 2014
page Contents – 2
CONTENTS
HPF - High Pass Filter ........................................................................................3-13
Metering ..............................................................................................................3-13
Equalizer Menu .......................................................................................................3-14
Manipulating Equalization Curves via Mouse ....................................................3-15
EQ Enable ..........................................................................................................3-15
Multiband Leveller Menu ........................................................................................3-16
A Word About Outboard Processors and Rreeveettbb .......................................3-16
iAGC Controls .....................................................................................................3-18
Gate Threshold ...............................................................................................3-18
iAGC Attack ....................................................................................................3-18
iAGC Release .................................................................................................3-18
RTZ Enable ....................................................................................................3-18
RTZ Down ......................................................................................................3-18
RTZ Up ...........................................................................................................3-18
Multiband Leveller Controls ................................................................................3-18
AGC Drive ......................................................................................................3-18
Gate Delay ......................................................................................................3-18
Leveller Gate Mode ........................................................................................3-19
Leveller Gate Threshold .................................................................................3-19
Crossover Frequencies ..................................................................................3-19
Band Coupling and Key Band ........................................................................3-19
Multiband Leveller Dynamic Displays Menu .......................................................3-20
Threshold ........................................................................................................3-22
Leveller Attack ................................................................................................3-22
Leveller Release .............................................................................................3-22
Density ............................................................................................................3-22
Compressor Attack .........................................................................................3-22
Compressor Release ......................................................................................3-23
Ratio ...............................................................................................................3-23
AGC Mix .........................................................................................................3-23
Stereo Enhance ..............................................................................................3-23
MB Limiter Menu ....................................................................................................3-25
Limiter and Clippers Controls .............................................................................3-25
Enable Limiters ...............................................................................................3-25
Multiband Limiter Drive ...................................................................................3-25
Limiter Knee ...................................................................................................3-26
Bass Clipper Threshold ..................................................................................3-26
Enable ............................................................................................................3-26
Bass Style 2 ....................................................................................................3-26
Main Clipper Drive ..........................................................................................3-26
Pre-Emphasis .................................................................................................3-26
FM Diversity Delay .........................................................................................3-27
Limiters and Clippers Dynamic Displays Menu ..................................................3-27
Threshold ........................................................................................................3-28
Attack ..............................................................................................................3-28
Release ..........................................................................................................3-28
Stereo Generator Menu ..........................................................................................3-29
Mode ...................................................................................................................3-29
Test Oscillator .....................................................................................................3-29
MPX Output Configuration ..................................................................................3-30
Composite Clipper Drive .................................................................................3-30
BS412 MPX Power Controller ........................................................................3-30
FM-55 / Aug 2014
page Contents – 3
CONTENTS
Pilot Injection ..................................................................................................3-30
Pilot Phase .....................................................................................................3-30
MPX Output ...................................................................................................3-31
Multipath Limiter ............................................................................................3-31
Using the Multipath Limiter With Stereo Enhancement .................................3-32
Analog L/R Output .............................................................................................3-32
Analog L/R Output Level ................................................................................3-32
De-Emphasis ..................................................................................................3-32
PreDelay .........................................................................................................3-33
Digital Output .....................................................................................................3-33
Digital Output Level ........................................................................................3-33
Baseband192 and AES Modes ......................................................................3-33
De-Emphasis .................................................................................................3-33a
PreDelay ........................................................................................................3-33a
Sample Rate ..................................................................................................3-33a
SCA Inputs ....................................................................................................3-33a
System Menu ..........................................................................................................3-34
Input/Output Settings Change With Preset .........................................................3-34
Metering Data Over TCP/IP ................................................................................3-35
System Status ....................................................................................................3-35
Security ...............................................................................................................3-35
Remote Login .................................................................................................3-35
Front Panel .....................................................................................................3-36
GUI Access .....................................................................................................3-37
GUI Lock .........................................................................................................3-37
Side Bar Region ........................................................................................................3-38
Preset .....................................................................................................................3-38
Library .....................................................................................................................3-38
Locking Presets ..................................................................................................3-39
How to View Preset Changes .............................................................................3-39
Save .......................................................................................................................3-40
Quick Save (QSave) ...............................................................................................3-40
Devices ...................................................................................................................3-41
Headphone Source .................................................................................................3-41
Headphone Control ................................................................................................3-41
Title Bar Region .........................................................................................................3-42
Status .....................................................................................................................3-42
Device .....................................................................................................................3-42
Current Preset ........................................................................................................3-42
Notes on Online and Offline Working .....................................................................3-43
Accessing Menu Options ...........................................................................................3-44
File Menu Items ......................................................................................................3-44
Hardware Menu Items ............................................................................................3-44
FM-55 Hardware Update ....................................................................................3-44
Preset Menu Items .................................................................................................3-46
FM-55 / Aug 2014
FM-55 / July 2015
page Contents – 4
CONTENTS
Appendices
Appendix A
General Specifications ..................................................................A-3
Appendix B
Interpreting Common Audio Processing Terms .........................A-8
Background ................................................................................................................A-8
Audio Terms and Wheatstone Processing .................................................................A-9
Thump/Rumble/Bottom ............................................................................................A-9
Punch/Boom/Tubby/Warm .....................................................................................A-10
Mud .........................................................................................................................A-10
Honk .......................................................................................................................A-10
Whack .....................................................................................................................A-10
Fuzzy/Tinny ............................................................................................................A-11
Sibilance .................................................................................................................A-11
Treble/Bright/Open .................................................................................................A-11
Finally .....................................................................................................................A-12
Appendix C
WheatNet-IP Configuration ..........................................................A-14
Adding FM-55 to The WheatNet-IP System ..............................................................A-14
FM-55 / Aug 2014
page Contents – 5
GENERAL INFORMATION
General Information
Chapter Contents
Introduction ....................................................................................1-2
FM-55 Feature Overview ...............................................................1-3
Rack Mounting ............................................................................... 1-3
FM-55 Installation Tips ...............................................................................................1-5
Grounding ...............................................................................................................1-5
Surge Protection .....................................................................................................1-5
UPS/Power Conditioning .......................................................................................1-5
Analog Audio Input Connections............................................................................1-5
Analog Audio Output Connections .........................................................................1-6
Digital Audio/baseband192 Connections ...............................................................1-6
Where to Install the FM-55 .........................................................................................1-7
Digital STL ..............................................................................................................1-7
Analog Left/Right STL ............................................................................................1-8
Composite Analog STL ..........................................................................................1-8
Analog Phone Lines ...............................................................................................1-8
Where Should Pre-Emphasis Go? ..........................................................................1-9
Ratings Encoders ...................................................................................................1-9
AC Power Considerations ............................................................1-9
Rear Panel Connections ..............................................................1-10
Audio Inputs ..............................................................................................................1-10
Analog In ................................................................................................................1-11
AES In .....................................................................................................................1-11
SCA In ....................................................................................................................1-11
FM Audio Outputs .....................................................................................................1-11
Analog Out .............................................................................................................1-11
AES/baseband192 Out ...........................................................................................1-11
TX Out ....................................................................................................................1-12
Headphone Monitoring ..............................................................................................1-12
Network Connection .................................................................................................1-12
Ethernet RJ-45 .......................................................................................................1-12
Typical Straight-Through Cable ..............................................................................1-12
Typical Crossover Cable .........................................................................................1-13
General Purpose Interface (GPIO) .............................................................................1-14
GPIO RJ-45 ............................................................................................................1-15
Processing Presets ....................................................................................................1-15
FM-55 Input/Output Connections Drawing ...............................................................1-17
FM-55 / Aug 2014
page 1 – 1
Introduction
GENERAL INFORMATION
General Information
Welcome to the Wheatstone FM-55 Digital Audio Processor. The FM-55 has been
carefully designed to deliver a clean and easy to listen to sound on the dial along with
very competitive loudness when that is the goal. The FM-55 expands on technologies
previously invented by Wheatstone, incorporates several new ones, and delivers that
“sought after” sound no matter what the market size. Like other Wheatstone processors,
the FM-55 has been carefully designed to not have a xed sound of its own – the end
user can use the FM-55’s vast pallet of tools to create any desired on-air sound.
The FM-55’s processing algorithms have been carefully evaluated though many
hours of critical listening with a very wide range of program material. The FM-55’s
processing algorithms deliver amazingly clean, clear, and if desired, loud, on-air sound.
Music sounds like it was meant to sound. Voices are rich and full and without unnatural
coloration or distortion. Transitions between widely varying program elements are deftly
handled, and if desired, with no trace of “processing” during spectral balance and density
corrections.
Remote control of the FM-55 is via a Windows-based Graphical User Interface (GUI)
software and can be accomplished via 100BaseT wired Ethernet. Up to four simultaneous
remote control sessions are possible. General Purpose Input/Output is provided on an
RJ-45 to interface to station systems.
The FM-55 utilizes an internal base sampling rate of 192 kHz. Higher sample rates
are used where it is benecial to do so, such as within the FM-55 clipper. A 24-bit, 144dB
internal dynamic range signal path allows audio to be processed with extreme precision.
The front panel OLED screen permits convenient control of system and basic processing
setup parameters and sound controls.
Those wishing for remote or PC control over all parameters will appreciate our
full-control GUI. This GUI is available free of charge and comes on a CD that accompanies
this product or can be downloaded at http://wheatstone-processing.com.
FM-55 / Aug 2014
page 1 – 2
GENERAL INFORMATION
Wheatstone products are designed and manufactured in our Corporate Headquarters
in New Bern, North Carolina, USA. This large, state-of-the-art facility affords complete
control over product quality during every step of the design and manufacturing process.
In order to maintain the high product quality that Wheatstone has been known for, no
offshore manufacturing is utilized.
The following pages will help you get the FM-55 up and running as quickly as
possible without having to know a lot of techie stuff.
If during installation or setup you nd that you need assistance or advice, please
feel free to contact our technical support folks at (252) 638-7000 or email us at:
techsupport@wheatstone.com.
FM-55 Feature Overview
The FM-55 Audio Processor has been designed to process audio for conventional
analog FM.
Input audio can be analog or digital, with options on the digital input via WheatNet-IP
or standard AES-3 connection. And input failover between the digital or analog inputs
is available.
Processing blocks include a phase rotator and high pass lter, a four band equilizer,
ve band iAGC processor and a ve band limiter.
The nal stage of the signal path utilizes a new clipper technology unique to the
FM-55. It’s followed by a composite processor which feeds the analog or digital
composite outputs simultaneously.
The FM-55 can be directly fed to an exciter in a number of ways. AES L/R may be
fed to an exciter if an all digital path is to be maintained. Conversely, the FM-55 can
also feed an AES composite signal to compatible exciters via Wheatstone’s baseband192
technology (MPX over AES).
Several dozen factory presets are provided with the FM-55, making a very wide
range of on air sounds and textures available to the user right out of the box. When
used in combination with the front panel’s Audio Processing Guru controls each factory
preset offers over a million different on-air sounds to the user.
The FM-55 is also equipped with Wheatstone’s ACI protocol, allowing complete
control of not only presets, but any parameter that is assigned to a user control (please
contact the factory for details on using this feature).
Rack Mounting
The FM-55 is designed to t into an industry standard 19" equipment rack, and
requires one rack unit (1.75") of vertical space. The unit has a depth of 9" behind the
rack rails (including chassis connectors), and its chassis has a width of 17-11/32". Space
needed in front of rack rails is 3/4" and an additional ve inches of space is required
for wiring cables to pass through. If using only two rack screws always use the bottom
two screws to prevent twisting of the front panel and other undue forces from harming
the processor chassis.
The FM-55 may be mounted between other devices in the equipment rack; however,
in accordance with good engineering practice it should not be mounted directly above
FM-55 / Aug 2014
page 1 – 3
GENERAL INFORMATION
devices that generate a signicant amount of heat (such as power ampliers or power
supplies). If such a location is unavoidable, then it is advisable to utilize an extra 1RU
blank rack panel between the FM-55 and devices imm ediately above and/or below it.
WARNING!
With very few exceptions, the FM-55 chassis DOES NOT need to be opened in the
eld.
Please be advised that the FM-55 contains high voltage power supply circuits
operating at voltages well above AC line input.
These voltages are hazardous and potentially deadly if accidentally contacted.
Special tools, software, and xtures are required for service. There are no
user‑serviceable parts inside.
The FM-55 unit must be returned to Wheatstone Corporation under a Return
Authorization in the unlikely event that repair is necessary.
If you need to return the FM‑55 to Wheatstone for repair, please
contact our ofce at 252-638-7000 Monday – Friday 8:30am to
5:30pm ET or after hours at techsupport@wheatstone.com for a
Return Authorization (RA) number.
FM-55 / Aug 2014
page 1 – 4
GENERAL INFORMATION
FM-55 Installation Tips
Grounding
Establish a low impedance common ground in the facility and try to route all
equipment grounds to that point. Use ground conductors with the largest possible
surface area and keep ground leads as short as possible. The FM-55’s ground reference
is its chassis, which should be connected to the station ground. Such a connection is
especially important when the FM-55 is operated in a high RF environment because it
helps minimize differential voltages between the processor’s chassis and other pieces
of equipment such as the rack it is mounted within.
Surge Protection
Always place surge protection circuits as close as possible to the device being
protected. AC power line surge protection should manage transients in a way that keeps
instantaneous potential differences between the power line hot, neutral, AC grounding
conductor, the station ground, and the processor chassis as low as possible. Likewise,
measures should also be taken to keep the instantaneous potential difference between
the audio cable shields and the processor chassis as low as possible (this applies to
all audio equipment, not just the FM-55), particularly when the equipment is located
within the electrically hostile environment of a station’s transmitter facility.
UPS/Power Conditioning
Choose the best power conditioning/UPS units that your budget will allow, focusing
on the most important features and options that you actually need. Some questions to
ask while reviewing features are:
- How does the UPS behave when AC power is not exactly 60Hz, such as when
the facility is on its backup generator?
- If the UPS has onboard surge protection, what kind of surge capability does it
have and where are those surges directed to?
- Is the UPS equipped with remote monitoring capability?
- Does the UPS have onboard monitoring and alarms to signal problems such as
low batteries?
Analog Audio Input Connections
Balanced audio input sources should be connected to the FM-55 using standard
two-conductor shielded audio cable such as Belden 8451 or 9451.
Unbalanced input audio connections
should be made with shielded two
conductor cable. At the unbalanced
source’s output connect the “+” output
to FM-55’s “Hi” input (XLR pin 2) and
connect the shield wire to the FM-55’s
“Lo” input (XLR pin 3). If the cable’s
shield is used (recommended) connect it
at the FM-55 end only (XLR pin 1) to
prevent AC ground loops.
FM-55 / Aug 2014
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GENERAL INFORMATION
If RF interference is an issue, the far (oating
and ungrounded) end of an audio cable
shield can be experimentally bypassed to
RF ground via a 0.01µF, 250V AC rated
capacitor. Suitable capacitors are:
TDK CS17-F2GA103MYGS
Murata DE2F3KH103MA3B
Panasonic ECK-ATS103MF
AVX 65N103MBLCP
Analog Audio Output Connections
Balanced audio loads are recommended and should be connected to the FM-55’s outputs
using standard two-conductor shielded audio cable. Unbalanced audio loads should be
avoided, but if they can’t they should be connected using shielded two conductor cable
such as Belden 8451 or 9451 (as if connecting a balanced source).
The FM-55 is equipped with active balanced output stage that behaves like a transformer.
Because of this behavior the correct wiring method may be different than expected.
The unbalanced load’s “Hi” lead should be
connected to XLR connector Pin
2 (“Hi”).
The unbalanced load’s shield should be
connected to the FM-55’s output XLR Pin 3
(“Lo”). Then, and to enable the FM-55’s
balanced output amplier to operate correctly when driving the unbalanced load, it is
recommended that the FM-55’s XLR output Pin 1 (ground/shield) also be connected to
Pin 3 (“Lo”), noting that this MUST BE DONE at the FM-55’s output connector (see
the diagram above).
Note that it is not advisable to connect Pin 1 and Pin 3 conductors together at the far
end of the cable. Doing so can induce external noise and crosstalk on the output amplier’s
“load sense” lead which is XLR Pin 3 when Pin 2 is being used as the “Hot.”
As in the input case, if RF interference is
an issue the far (oating) end of the cable
shield can be experimentally bypassed to
RF ground through a 0.01µF 250V AC
rated capacitor to see if it helps. Please
refer to the listing above for capacitors
known to be suitable for this task.
Digital Audio/ baseband192 Connections
For digital audio connections always use a good quality digital audio cable (or twisted
pair Category 5E/6 Network cable) having a characteristic impedance of 110 ohms. This
cable should be shielded where possible, and in the case of multi-pair cable, each pair
should be individually shielded. Foil shielding is recommended for permanent installations,
and a cable with foil shield plus an overall braid should be used in applications where
frequent exing of cables might occur.
FM-55 / Aug 2014
page 1 – 6
GENERAL INFORMATION
Generic “audio” cable such as Belden 8451 and 9451 may sometimes be used for
interconnecting AES3 digital audio devices as long as the cable is short. The actual
cable length that will work satisfactorily is determined by many factors including the
error correction and jitter tolerance of the AES3 receiver, the characteristics of the
digital cable driver and the characteristics of the specic cable being used and its length.
“Generic” analog audio cables usually have higher capacitance than digital cable and
high capacitance cables can impair the ability of the AES3 receiver to recover the digital
signal without errors. Increased jitter, dropouts, or no audio at all can be an indication
of an improper cable type.
Where to Install the FM-55
The best location to install the FM-55 is at the transmitter site. This requires that
a discrete Left/Right STL, either analog or digital, be involved in the signal path. The
major benet of a transmitter site installation is that it enables the use of the FM-55’s
built-in lab-grade stereo encoder which allows much tighter control of modulation peaks.
A transmitter site location has the additional benet of allowing the use of the FM-55’s
highly oversampled composite processor to gain an additional loudness advantage.
The Wheatstone composite processor is much cleaner and more forgiving than those
in other products, and in combination with the FM-55’s tight pilot and SCA protection
lters can create additional loudness without the audible grunge that composite clippers
typically create.
With the advent of Wheatstone’s baseband192 technology, the promise of an all
digital airchain that is as loud as its analog composite sibling is now a reality. Users
now have the option of deploying the FM‑55 and other Wheatstone processors using
traditional analog or MPX over AES with a compatible exciter.
We recommend that, whenever there is a choice between using an exciter’s composite
MPX, AES over MPX option, or AES3 input, the processor (any processor) should be
interfaced to the transmitter using the exciter’s AES over MPX or analog composite
stereo multiplex input. The exciter’s AES3 digital input may be “clean” and it may be
“digital,” but it also precludes the ability to gain additional loudness through the use
of the FM-55’s intelligent oversampled composite clipper. Also, depending on factors
including the sample rates being used the exciter’s AES digital input can exhibit inferior
peak control compared to the exciter’s composite input.
When the FM-55 is located at the studio and an STL is being used to send the program
material to the transmitter site there are several issues to consider:
Digital STL
There are two categories of Digital STL’s on the market – those with codec-based
audio compression and those with uncompressed linear audio.
When a digital STL employs codec-based audio compression the FM-55 should be
located at the transmitter site which places it after the codec. This is very important
because most codecs will sound better when presented with unprocessed studio audio
instead of highly processed and pre-emphasized audio from the processor’s output.
Further, the encoding schemes used in such STL’s cannot accurately pass the well-dened
peak levels created by the FM-55, creating a modulation (loudness) disadvantage.
FM-55 / Aug 2014
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GENERAL INFORMATION
Installing the FM-55 at the studio end of a “compressed” STL brings with it at least
two caveats:
- The FM-55 stereo generator and composite clipper will not be available. Many
digital exciters offer stereo generator and composite clipper functions, but their
clippers have historically been quite crude and spectrally “dirty” compared to
the FM-55’s exceptional clipper. Therefore exciter hosted composite clippers are
not the optimum choice when the station’s ultimate sound quality is important.
- Compressed STL’s do not perform well when presented with competitively
processed audio, especially when that audio is pre-emphasized. This is because
codecs do their work by examining the audio for opportunities to remove content
that shouldn’t be audible to the average human ear. When densely processed audio
is presented to a codec, there are fewer opportunities to remove redundant audio
information and then mask that removal from our hearing. When handling heavily
processed (limited dynamic range) material codec operation can be much more
obvious – even to the point of being objectionable – than when the processing
is located after the codec where the masked artifacts are only occasionally and,
usually, minimally unmasked by processing gain.
Uncompressed (linear) digital STL’s have only one major installation limitation –
placing the FM-55 at the studio end of the STL will preclude the use of the stereo
generator and composite clipper.
TIP: If using the FM-55 at the studio be certain that any clippers and emphasis in the
stereo generator at the transmitter site are properly set up to complement the settings in
FM-55. This will prevent gross distortion and potentially large modulation overshoots.
Analog Left/Right STL
Older analog discrete left/right STL’s can suffer from an inability to control audio
peaks because of inadequate bandwidth in their IF circuits and/or poor low frequency
and phase performance. Individual left/right STL’s rarely have identical group delay
and this will adversely affect stereo separation when the signal is nally converted to
the multiplex composite domain. Such STL’s can also suffer from AFC bounce when
handling highly processed low frequency material, robbing modulation and reducing
on-air loudness.
Composite Analog STL
A high quality analog composite STL can have advantages over an analog left/right
STL in that it will typically have broader audio bandwidth and better audio performance
than discrete analog STL. Most also have the capability to add subcarriers for SCA and
RDS along with the composite audio. This means that many SCA and RDS generators
may be located at the studio end of the STL, which, along with the audio processor, makes
for a very convenient setup. With a modern composite STL and properly engineered
point-to-point path, the audio can be nearly as transparent as a digital STL.
Analog Phone Lines
Discrete left/right analog “phone line” STL’s are not recommended because of the
inability of most Telco service providers to meet the at frequency response and phase
matching requirements. Furthermore, in many countries wideband analog circuits have
FM-55 / Aug 2014
page 1 – 8
GENERAL INFORMATION
become unavailable or their cost prohibitive. On the other hand if the wired STL is a
dedicated (and equalized if necessary) pair of circuits that is under the station’s full
control it may be acceptable.
Where Should Pre-Emphasis Go?
Pre-emphasis should always be applied by the audio processing, and never by
the exciter. Modern FM audio processors are equipped with highly rened and very
sophisticated technology to manage the myriad challenges posed by FM pre-emphasis.
They can provide very tight modulation control with very low perceived distortion.
No FM exciters have this technology.
To summarize: the best location overall for the audio processor is always at the
transmitter.
Ratings Encoders
Field experience has been that Wheatstone audio processors favorably pass the
data watermarking scheme used in the rating service technology, regardless of the
aggressiveness of the processing being performed.
AC Power Considerations
Please note that in order to enhance its long-term reliability, the FM-55 has no
power switch because all power switches notoriously become intermittent over time
without regular use.
The FM-55 accepts AC line input voltages between 90 and 260 VAC, 50 or 60Hz.
Power consumption is under 100VA.
Although aggressive AC input ltering is utilized on the AC power input it is always
advisable to use external surge protection and an uninterruptible power supply (UPS)
wherever possible, especially where the AC power quality can be in question, such
as at a remote transmitter site.
Power conditioning, surge suppression, and even power backup devices are wise
investments when using sensitive modern electronic devices. The FM-55 is, after all,
a highly specialized “computer.”
The use of a UPS as recommended will protect the FM-55 from short duration
power interruptions and glitches which might otherwise signal it to reboot. When the
FM-55 reboots there will be a loss of audio for approximately 15 seconds.
FM-55 / Aug 2014
page 1 – 9
GENERAL INFORMATION
Rear Panel Connections
The image below shows the rear panel of the FM55 and the location of various
connectors associated with an installation:
FM-55 Rear Panel Connections (left to right)
CONNECTOR TYPE FUNCTION & NOTES
1 XLR Female Left Analog Input
2 XLR Female Right Analog Input
3 XLR Male Left Analog Output (FM processed Audio)
4 XLR Male Right Analog Output (FM processed Audio)
5 BNC Female
6 BNC Female
7 BNC Female
8 BNC Female
9 XLR Female
10 XLR Male
11 RJ-45
12 RJ-45
13 IEC
SCA Input #1 (for reliable connection use 50 Ohm male connector)
SCA Input #2 (for reliable connection use 50 Ohm male connector)
TX Output #1 (for reliable connection use 50 Ohm male connector)
TX Output #2 (for reliable connection use 50 Ohm male connector)
AES Audio Input
AES Audio Output (switchable between L/R and baseband192)
GPI Interface
Ethernet (Network) Connection / WheatNet-IP audio connection
Mains connection (90-240~VAC / 50-60Hz)
Audio Inputs
The FM-55 accepts three types of audio input sources:
• Balanced analog line level left/right audio;
• Digital AES3 compliant left/right audio with sample rates between 32kHz and 96kHz;
• WheatNet-IP via 100BaseT Ethernet connection to a WheatNet-IP audio network.
Input audio can be applied to any or all inputs simultaneously with the caveat that
the WheatNet-IP input and AES3 inputs share a common digital path into the internal
processing.
Automatic audio failover from analog to digital or vice versa is supported. Automatic
failover from AES3 or WheatNet-IP to analog is instantaneous and based on invalid or
missing bits in the AES3 or WheatNet-IP stream, or after 30 seconds of “silence” (level
below -42dBFS).
Automatic failover from analog to AES3 or WheatNet-IP is based on silence sense
responding to audio on both channels being below -42dBFS for more than 30 seconds.
Failover capability is not available between the AES and WheatNet-IP inputs.
FM-55 / Aug 2014
page 1 – 10
Analog In – XLR-F
Pin 1 XLR LT SH – LINE LT IN SH
Pin 2 XLR LT HI – LINE LT IN HI
Pin 3 XLR LT LO – LINE LT IN LO
Pin 1 XLR RT SH – LINE RT IN SH
Pin 2 XLR RT HI – LINE RT IN HI
Pin 3 XLR RT LO – LINE RT IN LO
AES In – XLR-F
Pin 1 XLR SH – AES IN SH
Pin 2 XLR HI – AES IN HI
Pin 3 XLR LO – AES IN LO
SCA In – BNC
Pin 1 BNC 1 HI – SCA 1 IN HI
Pin 2 BNC 1 SH – SCA 1 IN SH
Pin 1 BNC 2 HI – SCA 2 IN HI
Pin 2 BNC 2 SH – SCA 2 IN SH
GENERAL INFORMATION
FM Audio Outputs
Output audio for the FM path is available as:
• Balanced analog left/right stereo, pre-emphasized.
• Balanced analog left/right stereo, pre-emphasized or de-emphasized according to
pre-emphasis in use.
• AES3 digital left/right stereo, pre-emphasized or de-emphasized according to
pre-emphasis in use.
• AES3 digital composite (baseband192) connected to compatible transmitter*.
• Unbalanced composite stereo on two BNC female connectors.
• WheatNet-IP audio network.
*The AES digital output connector is switchable between left/right stereo and digital composite
(baseband192)
Analog Out – XLR-M
Pin 1 XLR LT SH – LINE FM LT OUT SH
Pin 2 XLR LT HI – LINE FM LT OUT HI
Pin 3 XLR LT LO – LINE FM LT OUT LO
Pin 1 XLR RT SH – LINE FM RT OUT SH
Pin 2 XLR RT HI – LINE FM RT OUT HI
Pin 3 XLR RT LO – LINE FM RT OUT LO
AES / baseband192 Out – XLR-M
Pin 1 XLR SH – AES FM / BASEBAND192 OUT SH
Pin 2 XLR HI – AES FM / BASEBAND192 OUT HI
Pin 3 XLR LO – AES FM / BASEBAND192 OUT LO
FM-55 / Aug 2014
page 1 – 11
GENERAL INFORMATION
C
C
C
C
TX Out – BNC
Pin 1 BNC 1 HI – TX 1 OUT HI
Pin 2 BNC 1 SH – TX 1 OUT SH
Pin 1 BNC 2 HI – TX 2 OUT HI
Pin 2 BNC 2 SH – TX 2 OUT SH
Headphone Monitoring
An overload protected stereo headphone amplier drives the front panel ¼" stereo
headphone output located on the left side of the FM-55’s front panel. The audio source
feeding the headphones may be chosen from the FM output or the analog and digital
inputs, even if those inputs have not been selected to feed the audio processing chain.
The System menu of the GUI hosts the headphone router selector as does the front
panel interface.
Network Connection
The FM-55 can connect to a network or PC/laptop over Wired Ethernet via the
100Base-T Ethernet port on the rear panel. This port is completely independent
and Auto-MDIX, allowing it to support straight-through and crossover cables in
any combination. The wired Ethernet interface can support up to four simultaneous
connections to remote GUIs.
For typical CAT5 cable pinouts see below. These connections are for communicating
with the conguration computer via a network.
Ethernet – RJ-45
Pin 1 – TXD +
Pin 2 – TXD Pin 3 – RXD +
Pin 4 – N/C
Pin 5 – N/C
Pin 6 – RXD Pin 7 – N/C
Pin 8 – N/C
Typical Straight -Through Cable
PIN
TXD +
TXD -
RXD +
N/
N/
RXD -
N/
N/
RJ-45
Plug
White/Orange
Orange
White/Green
Blue
White/Blue
Green
White/Brown
Brown
1
2
3
4
5
6
7
8
PIN
White/Orange
1
Orange
2
White/Green
3
Blue
4
White/Blue
5
Green
6
White/Brown
7
Brown
8
RJ-45
Plug
FM-55 / Aug 2014
page 1 – 12
GENERAL INFORMATION
C
C
C
C
C
C
C
C
Typical Crossover Cable
RJ-45
Plug
White/Orange
Orange
White/Green
Blue
White/Blue
Green
White/Brown
Brown
PIN
1
2
3
4
5
6
7
8
TXD +
TXD -
RXD +
N/
N/
RXD -
N/
N/
RXD +
RXD -
TXD +
N/
N/
TXD -
/
N
N/
PIN
White/Green
1
Green
2
White/Orange
3
Blue
4
White/Blue
5
Orange
6
White/Brown
7
Brown
8
RJ-45
Plug
FM-55 / Aug 2014
page 1 – 13
GENERAL INFORMATION
General Purpose Interface (GPIO)
The FM-55 is equipped with two General Purpose input (GPI) and output (GPO) ports
on the rear RJ-45 connector. The General Purpose connections are optically-isolated from
FM-55’s internal circuitry to prevent external ground loops and to prevent dangerous
voltages from being introduced into FM-55.
• GP Input #1 – Forces Analog Input regardless of currently selected input.
• GP Input #2 – Forces Digital Input regardless of currently selected input.
• GP Output #1 – Analog Input is selected.
• GP Output #2 – Digital Input is selected.
Each of the General Purpose inputs is current limited by 475 Ohm internal resistance.
The LED device inside the opto-isolators is rated at a maximum forward current of 50mA
and a normal operating current of 5mA.
Before connecting external circuitry to the General Interface inputs,
rst ascertain whether it will be necessary to utilize additional outboard
series resistance in your application!
Use the following table to determine if an external resistance is required and if so, what
value it should be. Note that a one-half watt resistor is sufcient. The resistance values in
the table below have been calculated to result in approximately 5.0 milliamperes forward
current through the opto-isolator’s internal LED.
APPLIED VOLTAGE TO GPI EXTERNAL RESISTANCE
3.3 Volts None
5.0 Volts 330 Ohms
6.0 Volts 470 Ohms
7.5 Volts 820 Ohms
10.0 Volts 1.3 kOhms
12.0 Volts 1.8 kOhms
12.0 Volts 2.4 kOhms
24.0 Volts 3.9 kOhms
30.0 Volts 5.1 kOhms
*48.0 Volts* 9.1 kOhms
* For personal safety reasons a voltage in excess of 48VDC is
NOT recommended to be applied to the General Purpose inputs.
The opto-isolators on the General Purpose outputs protect internal FM-55 circuitry
from voltage up to 350 volts AC or DC. The MAXIMUM permissible load current is
100 milliamperes (0.10 Amperes).
FM-55 / Aug 2014
page 1 – 14
GENERAL INFORMATION
GPIO - RJ-45
The pin assignment for the rear panel RJ-45 GPI connector is as follows:
Pin 1 – GPI I IN +
Pin 2 – GPI 1 IN Pin 3 – GPI 2 IN +
Pin 4 – GPI 2 IN Pin 5 – GPI 1 OUT +
Pin 6 – GPI 1 OUT Pin 7 – GPI 2 OUT +
Pin 8 – GPI 2 OUT -
Processing Presets
The FM-55 comes equipped with several dozen factory presets and can hold a total
of 80 presets in its onboard memory. Customer-created presets may be saved within the
FM-55’s onboard memory until all preset storage slots are full. An unlimited number
of presets can be stored on the PC that hosts the Windows-based remote control GUI
software.
In order to prevent annoying clicks and pops when changing presets, preset parameters
are slewed between the current values and the new values whenever a new preset is
taken, and it may take several seconds for the new settings to completely settle in. It is
important to remember this concept!
The FM-55’s preset behavior is purposely designed to make preset changes as
unbox-erosive as possible and therefore parameter changes are not instantaneous, but
gracefully take place over a matter of seconds. This factor must be taken into consideration
whenever switching back and forth between presets in order to compare them!
When a preset has been recalled and has not been modied the preset’s name is
displayed in green text within the GUI’s current preset window. If changes to the preset
have been made its name will be displayed in red text instead of green. Once the modi-
ed settings have been saved back to the FM-55’s hardware the preset name will again
be displayed in green.
Factory presets can be re-tuned and saved as new preset names in order to create a
completely different air sound. The factory presets are write-protected and changes made
to them cannot be written back to the same memory location. Factory presets that have
been modied are considered by the system to be “user” presets and therefore must be
saved as a new name and in a new preset storage slot.
Our advice is to start with a factory preset that has the on air sound that is closest
to what you believe you need. If changes are necessary, the best approach is to make
small changes, one or two at a time, and then listen for quite a while before deciding
that more changes are necessary. A consultant friend of ours advises: “Tweak small and
then listen large.”
NOTE:
Preset storage is as follows:
- Factory presets are installed beginning with a BYPASS stored in slot #9. Factory
presets cannot be written over or deleted.
FM-55 / Aug 2014
page 1 – 15
GENERAL INFORMATION
- User presets are stored above the highest-numbered factory preset or in slots
1 - 8. The number of available slots for user presets depends on how many factory
presets were installed, which can vary with software version. The total number
of presets on the FM-55’s hardware cannot exceed eighty (80). The storage space
available for presets on the GUI’s host PC (because of a preset’s tiny le size) is
virtually unlimited.
- User presets may be locked at the user’s discretion to prevent inadvertent changes.
Any user can unlock user-locked presets.
FM-55 / Aug 2014
page 1 – 16
ANALOG IN
ANALOG OUT
TX OUT
AES OUT / BASEBAND192
ETH
XLR-F - L
2 1
3
XLR-F - R
2 1
3
PIN 1 - LINE LT IN SH
PIN 2 - LINE LT IN HI
PIN 3 - LINE LT IN LO
PIN 1 - LINE RT IN SH
PIN 2 - LINE RT IN HI
PIN 3 - LINE RT IN LO
XLR-M - L
1 2
3
XLR-M - R
1 2
3
PIN 1 - LINE FM LT OUT SH
PIN 2 - LINE FM LT OUT HI
PIN 3 - LINE FM LT OUT LO
PIN 1 - LINE FM RT OUT SH
PIN 2 - LINE FM RT OUT HI
PIN 3 - LINE FM RT OUT LO
1
BNC - TX
2
1
BNC - SCA
2
PIN 1 - TX 1 OUT HI - CENTER PIN
PIN 2 - TX 1 OUT SH - SHELL
PIN 1 - TX 2 OUT HI - CENTER PIN
PIN 2 - TX 2 OUT SH - SHELL
SCA IN
PIN 1 - SCA 1 IN HI - CENTER PIN
PIN 2 - SCA 1 IN SH - SHELL
PIN 1 - SCA 2 IN HI - CENTER PIN
PIN 2 - SCA 2 IN SH - SHELL
XLR-M
1 2
3
XLR-F
2 1
3
PIN 1 - AES FM / BASEBAND192 OUT SH
PIN 2 - AES FM / BASEBAND192 OUT HI
PIN 3 - AES FM / BASEBAND192 OUT LO
AES IN
PIN 1 - AES IN SH
PIN 2 - AES IN HI
PIN 3 - AES IN LO
RJ-45
RJ-45
1
2
3
4
5
6
7
8
TXD +
TXD –
RXD +
RXD –
GPI
1
2
3
4
5
6
7
8
GPI 1 IN +
GPI 1 IN –
GPI 2 IN +
GPI 2 IN –
GPI 1 OUT +
GPI 1 OUT –
GPI 2 OUT +
GPI 2 OUT –
FM-55 / Aug 2014
FM-55 Input/Output Connections
page 1 - 17
FRONT PANEL
FM-55 Front Panel
Chapter Contents
Meters ............................................................................................. 2-2
Input Level Meters ......................................................................................................2-2
AGC Meters ................................................................................................................2-2
Limiter Meters ............................................................................................................2-3
Output Meters ............................................................................................................2-3
OLED Display ................................................................................. 2-3
Headphone .................................................................................................................2-5
Source Selection .....................................................................................................2-5
Headphone Volume .................................................................................................2-5
Presets .......................................................................................................................2-5
Input ...........................................................................................................................2-5
Input Source ............................................................................................................2-5
Input Gain Adjustment .............................................................................................2-6
Pre-Emphasis .............................................................................................................2-6
Sound .........................................................................................................................2-6
Texture .....................................................................................................................2-6
EQ ............................................................................................................................2-7
Save .........................................................................................................................2-7
A Note About The Front Panel Sound Adjustments ................................................2-7
Output ........................................................................................................................2-8
Network ......................................................................................................................2-9
Changing The Network Settings ............................................................................2-9
Leading Zeroes ........................................................................................................2-9
Default IP Address ...................................................................................................2-9
Vesions .......................................................................................................................2-9
Access .......................................................................................................................2-10
FM-55 / Aug 2014
page 2 – 1
FRONT PANEL
FM-55 Front Panel
Meters
On the front panel of the FM‑55 are eighteen columns of multicolored LEDs
representing the audio input levels, mutliband AGC gain reduction, multiband limiter
gain reduction, and the digital and TX 1 and TX 2 MPX outputs, respectively.
Input Level Meters
The input level meters have a scale showing the uppermost 42dB of the FM‑55’s
internal, 24‑bit, 144dB dynamic range. Levels which fall below the ‑42dB point on
the input meter are also the assigned trip levels for automatic input failsafe when that
feature is enabled (see page 3‑12 for input auto failsafe).
Please take note that the levels shown on the Input/Output meters are calibrated in
dBFS which stands for deciBels Full Scale. “0”dBFS is important because it is where
there are no more digital bits available to dene the audio. Audio levels can never exceed
0dBFS and severe clipping distortion will result if the audio attempts to exceed it.
Please also note that the LED indicator for the ‑12dBFS level is yellow in order to
warn the operator that there isn’t much digital headroom left above that level. Therefore,
normal input levels will usually fall between ‑24dBFS and ‑18dBFS with an occasional
peak at ‑12dBFS. The input meters always show the audio input level from the currently
selected input, analog or digital (AES3 or WheatNet‑IP).
AGC Meters
There are six columns for the multiband AGC gain reduction meters. The rst column
stands alone and indicates how much gain the iAGC, or Intelligent AGC, is controlling
the multiband AAGC’s behavior. This scale has a 21dB range. See the Chapter 3 on the
iAGC for a deeper explanation of its behavior and tuning.
The next ve meter columns show the amount of gain reduction being done in each
of the AGC’s ve frequency bands. Normal gain reduction values will run somewhere
around -6 to -15dB. See the Chapter 3 on the multiband AGC for a deeper explanation
of its behavior and tuning.
FM-55 / Aug 2014
page 2 – 2
FRONT PANEL
Limiter Meters
There are ve limiter meters for the multiband limiter, plus one more for the nal
limiter. These meters only have a 14dB scale since limiters do much less work on the
audio than the AGC section does. Please see the Chapter 3 on the multiband limiter for
a deeper explanation on its operation and tuning.
Output Meters
There are two sets of output meters, each with two bargraph columns. Like the input
meters, the output meters show the upper 42dB of the FM‑55’s internal, 144dB dynamic
range.
The digital output meters show the individual output levels on the left and right
channels as the audio exits the processing. IMPORTANT NOTE: These meters indicate
the levels after the output level controls.
The TX Out meters also have two columns, one for the TX1 output and one for TX2.
These meters represent the audio levels as they exit the processing stages and therefore
under normal operation will be seen peaking near the top of the meter column, and do
not change if the actual output levels are adjusted.
OLED Display
On the front panel of the FM-55 is an OLED display that quickly and easily allows
you to set up, congure and place the processor on the air with a preset without having
to set up the GUI interface. You can also make adjustments to the audio and set up user
access to the front panel from this screen.
Adjustments are simple.The knob
navigates up and down a menu when there
is a list, or scrolls thru options in a sub‑
menu once one has been selected. Pushing
the knob “takes” an option, while the “W”
(WheatNet‑IP) button backs out of a submenu
to the main menu.
The main menu of the FM‑55 shows all of the options available from
the front panel. These options are:
• Headphone – Selects the headphone source and volume level.
• Presets – Selects a user or factory preset to place on the air.
• Input – Selects the input mode (Analog, Digital AES or Digital
WheatNet‑IP) and sets the gain structure for the analog and digital
modes.
FM-55 / Aug 2014
page 2 – 3
FRONT PANEL
• Pre-Emphasis – Sets the pre‑emphasis used, depending on your
region and application. The options are FLAT, 50us and 75us.
• Sound – Allows basic sound adjustments of the selected preset.
• Output – Selects the output level of the composite and AES outputs
as well as the pilot level and SCA injection levels.
• Network – Shows the current IP Address, Subnet and Gateway
assigned to the FM‑55. These settings can also be edited from this
submenu.
• Version – Displays the current version of software running on the FM‑55.
• Access – Allows you to set a password to lock out the front panel.
The front panel has a screen saver which activates after a few minutes of inactivity on
the front panel controls.
FM-55 / Aug 2014
page 2 – 4
FRONT PANEL
Headphone
The Headphone submenu gives you the option of adjusting the headphone volume
as well as selecting the monitoring source.
Source Selection
The rst option is the monitoring source. To change the source, push in the knob and
turn it to scroll thru the options. Once you have arrived at the monitoring source you
would like to hear, push the knob in. The monitoring options are:
• Input – The active input selected, either AES, WheatNet-IP or Analog)
• Analog Input (“Ana Inp”)
• Digital Input (“Dig Inp”) – Depending on the AES input selected on the input
menu. If AES is selected you will hear the AES input. If WheatNet‑IP is selected,
you will hear that.
• FM Output (“FM Out”) – The FM out option allows you to monitor the processed
signal just before it enters the MPX domain. The audio is peak controlled and
pre‑emphasized. Matching de‑emphasis may be selected in the output menu.
Once the source has been selected by pressing in the knob, the front panel will exit
the source selection mode.
Headphone Volume
To adjust the volume level, turn the knob to the second option and push the knob.
You can then adjust the volume to a safe and comfortable level by turning the knob.
Once complete, push the knob to exit the adjustment mode.
To return to the main menu, press the “W” BACK button.
Presets
The Preset submenu allows the user to pick any of the factory or user presets that are
loaded onto the hardware. To select a preset, turn the knob to highlight and then push
the knob in to activate the preset.
To return to the main menu, press the “W” BACK button.
Management of presets on the hardware can be accomplished via the PC GUI program
that communicates with the FM‑55. You can add, delete and back up presets from the
GUI. For more information about preset management with the GUI, please see page 3‑37
of this manual.
Input
The Input submenu allows you to change the input source to the processor as well
as adjust the input levels for each source independently.
Input Source
The rst option is input source. To select the input source, highlight “input src” and
push the knob in. Turn the knob to select the option you wish to place on air.
FM-55 / Aug 2014
page 2 – 5
FRONT PANEL
The options are:
• Digital AES (“Dig AES”). This is the audio that appears on the XLR AES3 input
jack on the back of the processor.
• WheatNet-IP (“Dig WIP”). This is the audio that is streamed to the processor via the
Ethernet jack. This option should only be selected if the FM‑55 is part of a WheatNet‑IP
AoIP system and the processor has been added to the system as a third‑party device.
For more information on how to set up the FM‑55 for WheatNet‑IP, please see
Appendix C of this manual.
• Analog (“Analog”). This is the audio that appears on the balanced XLR analog L/R
input jacks on the back of the FM‑55.
Once the source has been selected by pressing in the knob, the front panel will exit
the source selection mode.
Input Gain Adjustment
The second option in the submenu are adjustments of the analog and digital input
levels. Highlight the gain adjustment for the active input (which was selected above) by
turning the knob and then pressing in the knob. While watching the input meters on the
front panel, adjust the input level so that the average level lights the ‑24dBfs LED with
peaks no higher than ‑12dBfs.
If all the operating levels in your system are calibrated, your input gains should be a 0.
If there is an issue where a level is too hot or cold, you can correct that here, however, it
is advised to go back and look at where the level discrepancy originated and resolve the
issue at that point, then return the operating level of the FM‑55 to unity gain.
Once the input gain has been adjusted, press the knob in to exit the adjustment option.
To calibrate the levels of non‑active “backup audio source” inputs, you will need to
activate the input as the main input to see its operating levels. A more comprehensive input
adjustment menu is available in the PC based GUI software, which includes a balance
control and setting up main and backup audio sources.
To return to the main menu, press the “W” BACK button.
Pre-Emphasis
Pre-Emphasis has three options: Off, 50uS, and 75uS. The Off position is useful for
testing and would not normally be used for broadcast. The 50uS or 75uS position should
be selected to conform to your locale and regulatory requirements.
Sound
Probably THE place you wanted to touch rst… admit it! Sound can help adjust a
factory preset to tailor it to your tastes. The controls found here do basic adjustments only,
to speed up or slow down the processing and to add or cut bass and highs.
Texture
The texture controls adjust the amount of processing, how fast the processing will
react to gain changes and trade‑offs between clean audio and loud audio. Because of the
advanced algorithms of the FM‑55, the tradeoff between loud and clean is much easier
than in older analog designs or even inadequate or primitive digital processor designs
FM-55 / Aug 2014
page 2 – 6
FRONT PANEL
from other manufacturers. Thus, you can get away with more “pushing the envelope”
than ever before.
The three texture controls are:
• Leveler Depth – Drives the AGC gain. Higher numbers mean the Leveler will work
harder to bring up low levels. Lower numbers mean the leveler will relax to a more
open sound.
• Density – Determines how fast the processor will react to changes in level and how
consistent the audio spectrum will remain cut to cut. Higher numbers mean faster
changes and more consistent tonal balance. Lower numbers relax the audio and
allow the spectrum to retain some of the intended source tonal balance.
• Loudness – Determines how fast the peak control processing will react. Higher
numbers mean faster limiting and more clipping depth while lower numbers relax
the limiters and clippers for a more open sound will still maintaining excellent peak
control.
To access these controls, select the TEXTURE option by highlighting it and pressing in
the knob. You can then highlight the texture feature you want to adjust by highlighting it
and pressing in the knob. All the texture features are adjustable on a scale from 0-10 with
0 being the lowest setting and 10 being the highest. The default for all factory presets is 5.
EQ
To access the EQ controls, select the EQ option by highlighting it and pressing in the
knob. You can then highlight the EQ option you want to adjust by highlighting it and
pressing in the knob. All EQ features are adjustable on a scale from 0‑10 with 0 being
the lowest setting and 10 being the highest. The default for all factory presets is 5.
To return to the main menu, press the “W” BACK button.
Save
When you are nished adjusting the TEXTURE and EQ controls, you can save your
work as a preset using the SAVE option. In the menu, highlight the SAVE option with
the knob and press it in. The next empty user preset slot will appear with the option of
naming your new preset (the FM-55 has 80 preset slots, the rst 20 of which are used for
factory presets). You can use the new slot, or turn the knob and select a different empty slot
OR overwrite a previously saved user preset (factory presets CANNOT be overwritten).
Once a slot has been selected, you can name the preset using the knob. A ashing
cursor will appear in the rst character slot. Turn the knob to choose an alpha-numeric
character and push select. The character will be written and the cursor will move on to
the next character. When you are nished, push and HOLD the knob for approximately
3 seconds to save the preset. A total of 8 characters can be chosen for a preset saved on
the front panel. These can only be alpha‑numeric (A‑Z or 0‑9). For longer, more descrip‑
tive names, you can use the PC GUI to save the current preset with up to 64 characters.
A Note About The Front Panel Sound Adjustments
The front panel sound adjustments are set up so that users can quickly change the most
basic settings in the audio processor to “get it” on the air and sounding good. Because
we have tied together background controls to make the front panel adjustments easy, you
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FRONT PANEL
can only modify factory presets from the front panel. User presets, adjusted and saved
with the GUI software, cannot be modied from the front panel. Any preset may be
selected, but only genuine Wheatstone factory presets can be modied using the sound
controls on the front panel.
That being said, the front panel controls are very powerful for what they are. If you
don’t want to bother with the GUI software, the best way to proceed with selecting and
adjusting a preset using the front panel controls is to nd a preset that closely matches
the sound you are looking for. Don’t get too wrapped up with names… what may sound
great for CHR in one market may be way too aggressive in another.
Each of the 5 controls has 10 options, which leads to 100,000 different settings that
can be made JUST WITH the 5 front panel controls. In most markets, you can at least
get up and running with something that sounds really good with just these 5 controls
and the factory presets. In some markets, it may be ALL you need!
Output
The Output submenu allows you to congure the composite and AES
output levels and well as the pilot and SCA injection levels.
The adjustments in this submenu are:
• TX1 Level (“Tx1 Lvl”) – Sets the level of the processor’s TX1 BNC
output. If baseband192 is an selected as an option, the digital output
control governs the baseband 192 output level (which appears on
the AES XLR connector).
• TX2 Level (“Tx2 Lvl”) – Sets the level of the processor’s TX2
BNC output. Use TX2 as a backup to TX1, or if you are using
baseband192 and need a composite output independent of TX1 for your backup.
Can also be used as a 19kHz reference (switchable in the PC GUI).
• Pilot Injection (“Pilot Inj”) – The Pilot Injection control adjusts the level of the
19kHz stereo pilot and is adjustable from 0 (Off) to 20% of the main composite
signal amplitude. Please refer to a properly calibrated modulation monitor to
properly make this adjustment. Normal pilot injection is 9%.
• Digital Output Level (“Dig Lvl”) – The FM Digital Output control sets the
absolute peak output level in dBFS after all processing. This audio appears on
the AES connector on the rear of the FM‑55 when the AES output is NOT set
to baseband192. When this output is set to baseband192, the digital output level
control sets the gain on this connector.
• SCA1 Injection (“SCA1 Inj”) – Inputs applied to the SCA connectors are high pass
ltered to reduce hum and then low-pass ltered at 94kHz before being digitized at
192kHz. The SCA injection levels can be set to OFF, or to levels between ‑79.95dB
and +10.0dB, in 0.05dB steps.
• SCA2 Injection (“SCA2 Inj”) – Secondary SCA input that functions in the same
manner as SCA1.
To change a setting, highlight the settings by turning the knob and the press the knob
in. The value will now be highlighted. Turn the knob clockwise or counter clockwise
to raise or lower the value. Push the knob in once you have reached the value to exit.
To return to the main menu, press the “W” BACK button.
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FRONT PANEL
Network
The Network submenu allows you to view and/or assign the IP
Address, Subnet and Gateway to the FM‑55 processor.
To view the FM‑55 Network settings, from the main menu, turn
the knob to highlight the Network option and press the knob in. You
will see the IP Address, Subnet, Gateway and MAC Address displayed.
Changing The Network Settings
Once you are in the Network submenu, changing the settings is
easy. Just turn the knob to highlight the address you want to change (IP
Address, Subnet or Gateway… the MAC Address is not adjustable. It
is a xed address unique to the particular FM‑55).
Once you have selected an address to edit, push in the knob and the rst set of
numbers in that eld will ash. Turn the knob up or down to increase or decrease the
numerical value. Once you have reached the desired value, push the knob in to move
to the next eld.
Once all of the elds are correct, dobby to the end of the address by pushing in the
knob until you are back to the submenu edit address selection. You can now turn the
knob to edit a different address.
Leading Zeroes
The FM‑55 uses IPv4 addresses that are canonically represented in dot‑decimal
notation, which consists of four decimal numbers, each ranging from 0 to 255 and
separated by dots. On the front panel and when assigning an IP address in the PC GUI,
one and two number elds do not have “leading zeroes”… for example, an address of
192.168.1.155 should be entered as shown in the PC GUI when setting up the GUI to
communicate with the FM‑55 just as it is written in this example. The front panel does
not allow the user to add “leading zeroes”, but it can be accidently entered into the PC
GUI. An incorrect way of entering the 192.168.1.155 address in the PC GUI would be
192.168.001.155. The correct way IS 192.168.1.155.
Default IP Address
The FM‑55 Default network settings are:
IP ADDRESS: 192.168.1.155
SUBNET: 255.255.255.0
GATEWAY: 192.168.1.1
Version
There are no editable elds in this submenu, rather it is a reference to what version
of rmware is running on your processor. When contacting technical support for your
FM‑55, you may be asked to look at this screen to verify what version of FM‑55 software
is running on your processor. The key piece of information for users is the SOFTWARE
version. This version must match the PC GUI version running on your computer for
you to be able to properly adjust the FM‑55 from your computer. For more information
on checking the PC GUI version, see page 3‑44 of this manual.
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FRONT PANEL
If the PC GUI and the version on the hardware are mismatched, you can contact
Wheatstone Technical Support at +1-252-638-7000 Monday thru Friday (except major
US holidays) from 8:30am to 5:30pm Eastern time. You can also email your FM-55
PC GUI and hardware versions to techsupport@wheatstone.com to obtain a copy of
the PC GUI that matches the version running on your hardware.
Access
Access to the front panel of the FM‑55 can be restricted with a password.
To set the front panel password:
• From the main menu, turn the knob to the Access option and push in the knob.
• Push the knob in again to Set Password (“Set PW”)
• A dialogue will open with the cursor set on the rst character. Turn the knob to
assign a numerical character as the rst of four numbers.
• When the character is set, push in the knob and the cursor will move to the next
slot.
• Once the four digit password has been created, push and hold the knob to save
the password.
When anyone attempts to access the processor front panel, they will be met with a
prompt to enter a password. To enter a password, turn the knob to the rst character,
scroll the correct digit, and press the knob in. The cursor will move to the next character.
Continue in this manner until the password has been entered, then press and hold the
knob. A message will tell you if the password is correct or incorrect.
It is important that you REMEMBER your password. Only numerical characters
can be used in password creation. If you lose your password, please contact Wheatstone
Technical Support at +1-252-638-7000 Monday thru Friday (except major US holidays)
from 8:30am to 5:30pm Eastern time.
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FM-55 GUI
FM-55 PC GUI
Chapter Contents
Getting Started ...............................................................................3-4
Connecting With the GUI ..............................................................3-5
Configuring the GUI ......................................................................3-5
Connecting Directly Without a LAN ............................................................................3-5
The FM-55 and Internet Security Concerns ...............................................................3-6
About DHCP and the FM-55 .......................................................................................3-6
The FM-55 Network Protocols and Ports Used ..........................................................3-6
Using the FM-55 GUI .....................................................................3-7
Dynamic Displays Region ...........................................................................................3-8
Frequency-Domain Graph .......................................................................................3-8
Managing the Blue Dots - Tutorial ...........................................................................3-8
Control Area Region ..................................................................................................3-10
Input Menu ..............................................................................................................3-11
Input Source .......................................................................................................3-11
Input Signal Presence ........................................................................................3-11
Input Failsafe ......................................................................................................3-12
Analog Input Gain ...............................................................................................3-12
Digital Input Gain ................................................................................................3-12
L/R Balance ........................................................................................................3-12
Phase Rotator .....................................................................................................3-12
HPF - High Pass Filter ........................................................................................3-13
Metering ..............................................................................................................3-13
Equalizer Menu .......................................................................................................3-14
Manipulating Equalization Curves via Mouse ....................................................3-15
EQ Enable ..........................................................................................................3-15
Multiband Leveller Menu ........................................................................................3-16
A Word About Outboard Processors and Rreeveettbb .......................................3-16
iAGC Controls .....................................................................................................3-18
Gate Threshold ...............................................................................................3-18
iAGC Attack ....................................................................................................3-18
iAGC Release .................................................................................................3-18
RTZ Enable ....................................................................................................3-18
RTZ Down ......................................................................................................3-18
RTZ Up ...........................................................................................................3-18
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FM-55 GUI
Multiband Leveller Controls ................................................................................3-18
AGC Drive ......................................................................................................3-18
Gate Delay ......................................................................................................3-18
Leveller Gate Mode ........................................................................................3-19
Leveller Gate Threshold .................................................................................3-19
Crossover Frequencies ..................................................................................3-19
Band Coupling and Key Band ........................................................................3-19
Multiband Leveller Dynamic Displays Menu .......................................................3-20
Threshold ........................................................................................................3-22
Leveller Attack ................................................................................................3-22
Leveller Release .............................................................................................3-22
Density ............................................................................................................3-22
Compressor Attack .........................................................................................3-22
Compressor Release ......................................................................................3-23
Ratio ...............................................................................................................3-23
AGC Mix .........................................................................................................3-23
Stereo Enhance ..............................................................................................3-23
MB Limiter Menu ....................................................................................................3-25
Limiter and Clippers Controls .............................................................................3-25
Enable Limiters ...............................................................................................3-25
Multiband Limiter Drive ...................................................................................3-25
Limiter Knee ...................................................................................................3-26
Bass Clipper Threshold ..................................................................................3-26
Enable ............................................................................................................3-26
Bass Style 2 ....................................................................................................3-26
Main Clipper Drive ..........................................................................................3-26
Pre-Emphasis .................................................................................................3-26
FM Diversity Delay .........................................................................................3-27
Limiters and Clippers Dynamic Displays Menu ..................................................3-27
Threshold ........................................................................................................3-28
Attack ..............................................................................................................3-28
Release ..........................................................................................................3-28
Stereo Generator Menu ..........................................................................................3-29
Mode ...................................................................................................................3-29
Test Oscillator .....................................................................................................3-29
MPX Output Configuration ..................................................................................3-30
Composite Clipper Drive .................................................................................3-30
BS412 MPX Power Controller ........................................................................3-30
Pilot Injection ..................................................................................................3-30
Pilot Phase .....................................................................................................3-30
MPX Output ...................................................................................................3-31
Multipath Limiter ............................................................................................3-31
Using the Multipath Limiter With Stereo Enhancement .................................3-32
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FM-55 / July 2015
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FM-55 GUI
Analog L/R Output .............................................................................................3-32
Analog L/R Output Level ................................................................................3-32
De-Emphasis ..................................................................................................3-32
PreDelay .........................................................................................................3-33
Digital Output .....................................................................................................3-33
Digital Output Level ........................................................................................3-33
Baseband192 and AES Modes ......................................................................3-33
De-Emphasis .................................................................................................3-33a
PreDelay ........................................................................................................3-33a
Sample Rate ..................................................................................................3-33a
SCA Inputs ....................................................................................................3-33a ..................
System Menu ..........................................................................................................3-34
Input/Output Settings Change With Preset .........................................................3-34
Metering Data Over TCP/IP ................................................................................3-35
System Status ....................................................................................................3-35
Security ...............................................................................................................3-35
Remote Login .................................................................................................3-35
Front Panel .....................................................................................................3-36
GUI Access .....................................................................................................3-37
GUI Lock .........................................................................................................3-37
Side Bar Region ........................................................................................................3-38
Preset .....................................................................................................................3-38
Library .....................................................................................................................3-38
Locking Presets ..................................................................................................3-39
How to View Preset Changes .............................................................................3-39
Save .......................................................................................................................3-40
Quick Save (QSave) ...............................................................................................3-40
Devices ...................................................................................................................3-41
Headphone Source .................................................................................................3-41
Headphone Control ................................................................................................3-41
Title Bar Region .........................................................................................................3-42
Status .....................................................................................................................3-42
Device .....................................................................................................................3-42
Current Preset ........................................................................................................3-42
Notes on Online and Offline Working .....................................................................3-43
Accessing Menu Options ...........................................................................................3-44
File Menu Items ......................................................................................................3-44
Hardware Menu Items ............................................................................................3-44
FM-55 Hardware Update ....................................................................................3-44
Preset Menu Items .................................................................................................3-46
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FM-55 / July 2015
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FM-55 GUI
FM-55 PC GUI
The FM-55 PC Graphical User Interface (or GUI) is an advanced user interface. This
GUI is designed to bring out all of the controls available to the user to adjust the sound
of the processor to t the needs of the station and format.
This GUI expands on the basic adjustment controls that are found on the front panel
of the FM‑55.
The FM‑55 GUI allows you to adjust the processor and see, in real time, how it is
reacting to the audio being processed. All Wheatstone GUI’s have been carefully designed
so that no adjustment is more than two mouse clicks away.
The FM‑55 GUI software may control an unlimited number of FM‑55’s via a standard
Ethernet network. Utilizing TCP and UDP protocols, the GUI can be used to control these
FM‑55 devices from anywhere in the world as long as there is an Internet connection.
This includes controlling it behind rewalls, NAT routers and VPN tunnels.
Getting Started
The FM‑55 GUI is a Windows™ based program is designed to be intuitive and
straightforward to use. The GUI installer is supplied on the product CD as an executable
program. Though the GUI may be installed to any folder on the host computer, the default
path is: C:\Program Files\Wheatstone\FM55. After installation, the GUI can be started
by clicking on the FM55 item in the Windows Start menu.
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FM-55 GUI
Connecting With the GUI
The FM‑55 and the PC running the FM‑55 GUI program can be straightforwardly
connected together over a standard Ethernet Local Area Network (LAN).
The FM‑55 should be installed, powered‑up, and veried to be operating normally.
A CAT5 Ethernet cable connected to the rear panel’s 100baseT LAN port should be
connected to the Ethernet port on the host PC. The FM‑55 is Auto‑MDIX so either a
straight‑through or crossover cable may be used.
Configuring the GUI
Assuming a valid IP address has been assigned to the FM‑55 and the GUI is now
installed, start the program to bring the GUI on the screen. Next, on the right side of
the GUI locate the Devices button and click on it. This will open the Edit Device dialog
which is used to tell the GUI what IP addresses and names the FM‑55 may have.
The Name eld can be left blank or used to give the FM‑55 a unique name in the
Devices display box at the top of the GUI – this is the device that the GUI is either
currently connected to, or congured to connect to if it is not yet connected. In the
IP Address eld enter the “HARDWARE” address that was previously assigned to the
FM‑55 and then click OK.
Highlight the new FM‑55 device in the Devices list and click on the Select button.
Now you can place the GUI online by clicking on the button to the left of the Status
message.
The indicator inside the button will be green when the FM‑55 GUI is communicating
with the FM‑55. Once the GUI has been made aware of the FM‑55’s existence in this
manner, it will always appear in the list of the FM‑55 Devices and it will be instantly
accessible from anywhere at any time.
When connected to the FM‑55 the status bar will indicate Online and the “Device”
text will show the name of the FM‑55 that it is currently communicating with (in this
example, the FM‑55 has been named WLNG). The status bar will also display the name
of the preset that the FM‑55 you’re connected to is currently running.
When the Preset name is showing as green text it means that a factory or user preset
is running and that no changes have been made to it. If the Preset name is showing in red
text, it means that the preset has had some changes made to it or is a work in progress
that has not yet been saved to the processor.
Connecting Directly Without a LAN
You can also work without a LAN by connecting the FM‑55 and the PC Ethernet
ports together with a standard Ethernet cable – either a straight‑through or crossover
cable may be used. As mentioned previously the FM‑55 has auto‑sensing, Auto‑MDIX
Ethernet ports.
NOTE: The controlling PC and the FM‑55’s network settings must be congured to
place them both on the same subnet!
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FM-55 GUI
The FM‑55 and Internet Security Concerns
The FM‑55 does not act as a “web device” or “web server,” nor does it support open
ports to the Internet. Therefore there is no worry that someone could “hack” into the
FM‑55 and use it as a pathway to the rest of the network to which it is connected.
About DHCP and the FM‑55
The FM‑55 does not utilize DHCP – Dynamic Host Conguration Protocol (or
automatically assigned network addressing) – and needs to be assigned a “STATIC”
network‑unique IP address. Most DHCP servers assign addresses starting at the bottom
of the group 192.168.0.xxx. Therefore choosing an address high in that group, say
192.168.0.200, as a static IP address will likely keep it out of the way of the busiest
DHCP addressing.
However, it’s always wise to check with your network administrator to determine
what static IP addresses may be open and usable for the FM‑55. Sometimes the local
network warrants the “Subnet” and “Gateway” values to be vastly different, but our
suggested starting values for the Subnet and for the Gateway usually sufce for all but
the most complex situations.
The FM‑55 Network Protocols and Ports Used
The FM‑55 uses both TCP and UDP protocols to communicate with the remote GUI.
TCP is used from the GUI to the FM‑55 because its high reliability ensures that all control
changes sent to the FM‑55 will be received with 100% accuracy. The UDP protocol is
used by FM‑55 to send and update metering and other real time data back to the GUI.
The TCP protocol uses port 55986. The UDP Protocol uses a port in the range between
60000 and 60010. It tries 60000 rst and if it is busy it tries 60001 next. This process
repeats if necessary until an idle UDP port is found. Note that FM‑55 requires these
ports to be open through any rewalls for successful connectivity.
For information on conguring the Network settings on the FM‑55, please see page
2‑9 of this manual.
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FM-55 GUI
Using the FM-55 GUI
The GUI may be positioned on the host computer’s screen by left‑clicking and holding
the “Wheatstone” logo and dragging the GUI to the desired position. In normal “Windows”
fashion, the GUI may be minimized on the desktop (taken off the screen) and/or closed by
way of the familiar controls at the extreme top right.
Descriptions of the features and functions of the GUI will follow different discrete
regions of the screen; it will begin with the most eye‑catching region – the Dynamic Dis‑
plays – and then we’ll explain the Control Area above it, followed by the Side Bar buttons,
and lastly the Title Bar.
TITLE BAR
TABS
CONTROL AREA
SIDE BAR
DYNAMIC DISPLAYS
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FM-55 GUI
Dynamic Displays Region
Frequency-Domain Graph
The most dominant display on the main screen is a large graphical area depicting
the audio frequency range of 20Hz – 20kHz arranged in logarithmic fashion with
gradations at selected frequencies. The scale of the vertical axis changes according
to its context.
Managing the Blue Dots – Tutorial
We’ve worked very hard on the design of the Wheatstone graphical user
interface to make it intuitive, friendly, and easy to navigate and interpret,
in spite of how many controls the user has access to.
Each of the processing section’s screens has a graphical area where
not only visual representations of processing activity are shown, but in
some cases individual adjustments of different sections of the processing
can be made.
All of the operating parameters of the ve band leveler, compressor, and limiter
can be individually adjusted by manipulating the positions of various “Dots” on that
section’s graphical screen. Each “dot” represents one processing
“band.”
By double clicking a blue dot (to highlight it and turn it Red)
and then dragging it with the mouse a particular parameter for a
band can be adjusted.
By right clicking on the graphical display area with your mouse
the options on the right will appear:
By default, all adjusters (the blue dots) are Grouped, that is they
are coupled to each other so that if you grab one with the mouse
(single left click and hold) and then slide the mouse up and down,
all blue points move up and down together.
When a blue dot is double‑clicked, it turns orange to indicate that it has been
selected. It then may be moved individually, and to anywhere along the vertical scale.
If another blue dot is clicked somewhere else on the line, it too will turn orange….
Now if you move the mouse to a point between the two dots selected in the above
steps, right click the mouse, and select UnGroup Adjusters, all the dots between the
rst two dots that were double clicked to turn them orange will also turn orange.
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FM-55 GUI
At this point all of the dots including and between the rst two dots may be individually
adjusted up or down. If you now place the mouse over the same graphical area, right
click again and this time select Group Adjusters the points between the rst two that
you highlighted will turn back to blue. If you then grab the line between these points
with the mouse again (left click and drag) you can move the entire line connecting the
two highlighted end dots up and down, with the two end points remaining anchored in
place. Cool, eh?
Right clicking on the graphical area and selecting Group All Adjusters removes
all highlighted dots turning them blue again. Conversely, right clicking and selecting
UnGroup All Adjusters turns all (remaining) blue points orange and they can now each
be individually adjusted. The Flatten function, although next in the list, is best explained
last….
Highlight a single dot again … any dot will do. Then right click the graphical area
and select Proportional Drag. Now left click any dot to the left or right of the dot you
highlighted and drag it up or down. See how the line behaves? It pivots at the point where
you highlighted the dot, and it bends at the point where you grabbed it with the mouse.
Virtually ANY curve can be created by following these steps. Now right click again and
this time select Flat Drag. Grab the line again… anywhere (left click and drag)… and
move it up and down. See how the line pivots at the highlighted point but remains at
above or below it as you raise and lower the line?
After these exercises the line is probably all messed up. You want to put it back to
where it was or at least make it all at again without having to move every single point
back, right? But how do you do that? It’s easy ... right click on the graphical area again
and select Flatten. If there were any points still highlighted orange you’ll want to rst
click Group All Adjusters before you select Flatten in order to turn them off. In any case,
when you nally click Flatten the line will return back to at and you may move it up
and down again with the mouse – this time as a whole.
To review:
Group Adjusters – Gangs the blue dots between two highlighted orange points into a
commonly behaving entity.
UnGroup Adjusters – Disconnects any blue dots that were grouped by “Group Adjusters.”
Group All Adjusters – Gangs all the dots, turning them blue, regardless of their previous
highlighting state.
UnGroup All Adjusters – Un‑gangs the adjustment dots and turns them orange, regardless
of any previous highlighting.
Flatten – Flattens into a horizontal orientation any dots not set to orange.
Proportional Drag – Allows the dragging of adjustment dots to create slopes anchored
if desired to a single orange set point.
Flat Drag – Allows the dragging of dots together in a “at” orientation.
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FM-55 GUI
Control Area Region
This is the large enclosed area directly above the graph and meters. The Multiband
Leveler section is shown here as an example.
All of the knobs, faders, switches, and check boxes affecting the sound of the audio
processing are located within this half of the GUI. To operate them, either:
Place the cursor over the desired control, and use the mouse’s scroll
wheel to increase or decrease the control’s position.
OR
Click on the control, and slide the mouse to move the control – up or
right increases the control’s indicated position, down or left decreases
it. When using the mouse in this fashion (as opposed to using the scroll
wheel), the resolution of the control variation can be increased – made
ner – by holding down the keyboard’s Ctrl key while adjusting the
control as above.
OR
In most cases you can double click on the text that indicates the setting
value (for example, the window that reads X.XdB under the Drive knob
on the Multiband AGC section) and a box will pop up where you can
enter an exact value and click OK.
From left‑to‑right across the upper portion of the graphical area are a series of buttons
corresponding to logically grouped processing sections in signal ow fashion in Input to
Output order.
A small green indicator at the left end of each button indicates if any signal processing
within that block is active. Left‑clicking a button opens the associated control panel to
gain access to the controls for that block of signal‑processing
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FM-55 GUI
INPUT MENU
This is the rst tab on the top far left of the GUI. (Note: the screen that is currently
being displayed is indicated by a green outline on the selection tab).
The Input screen contains controls for the input source selection, input failsafe, analog
and digital input gain controls, input left/right gain balance, phase balance, and the high
pass lter.
Input Source
The Input Sources can be selected as either Analog or Digital. There is one analog
input source. The FM‑55’s balanced audio inputs on its rear panel. There are two types
of Digital sources however, standard AES3 and WheatNet‑IP.
The currently selected input is shown by a yellow checkmark.
Input Signal Presence
Below the source selection check boxes are a pair of signal presence indicators. The
Analog indicator is green if there is a signal present on both left and right channels and
it is higher than ‑24dBu. The AES indicator turns green when there is a valid AES signal
present at the digital input and it is above ‑42dBFS.
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FM-55 GUI
Input Failsafe
In the event the currently selected input source fails and the Input Failsafe check
box is checked, an alternate source of audio which has been connected to the other
audio input can automatically be put on the air.
If the primary source was digital, the analog input will be selected immediately
if there are invalid bits in the data stream or missing audio data. Also, the analog
input will be selected after 30 seconds of a valid digital data stream having
signal levels below -42dBFS.
If the primary source was analog, then a silence sense timeout of 30 seconds
must elapse before the unit switches to the digital input. The audio failure sense
threshold is xed at -42dBFS, and this combination with the 30 seconds timeout
is suitable for virtually all program types.
NOTE: The input failover option can only switch between an analog input and a
digital input. Failover from WheatNet-IP to AES/EBU (or vice versa) is not supported.
Analog Input Gain
The Analog audio input gain can be adjusted by clicking on the knob and dragging
the mouse or touchpad to the right or left. The Analog Gain level can be adjusted over a
range of +/- 12dB.
Digital Input Gain
The AES/EBU and WheatNet-IP Digital audio input gain can be adjusted by
clicking on the knob and dragging the mouse or touchpad to the right or left. The
Digital Gain can be adjusted over a range of +/- 12dB. This knob controls both the
AES and WheatNet-IP input gain.
L/R Balance
Static level errors in Left/Right channel balance can be corrected by using the
L/R Balance knob. The Left/Right balance control affects all input sources and can
be adjusted over a +/- 12dB range. Usage of this control should be restricted to short
term “band-aid” use only since Left/Right channel balance is best corrected upstream
of FM-55 if it is out of balance.
Phase Rotator
Human voice is usually asymmetrical by nature, which means that it is usually
“peakier” in one polarity than the other, hence asymmetrical. What the Phase Rotator
algorithm does is x these asymmetrical peaks. The way it works is by phase shifting
the signal harmonics relative to their fundamental frequencies. This action reduces
the peak to average ratio and enables an increase in apparent loudness with minimal
audible detriment. We do this because processing the audio for a symmetrical medium
like FM is greatly simplied if the waveforms are symmetrical.
Ordinarily, human voice looks like the waveform below. Notice how the width and
amplitude of the upper and lower signal peaks are different? This is “asymmetry,” and
it makes the processing of voice waveforms more difcult.
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FM-55 GUI
Human voice before Phase Rotator algorithm
After passing through the Phase Rotator the same voice appears like the waveform at
left. Now the upper and lower portions of the waveform have equal distribution. In the
process no sound is lost and no distortion is created. Only the signal’s phase relationships
are rearranged.
Human voice after Phase Rotator algorithm
HPF – High Pass Filter
The High Pass Filter is used to remove inaudible and unnecessary subsonic
energy from the audio signal prior to it being processed. By removing this energy,
processing is cleaner and modulation energy is not wasted by transmitting sounds
that will not be perceptible to a listener.
The High Pass Filter also removes subsonic energy that could upset the
operation of equipment later in the audio chain, such as the AFC loop in the
FM exciter.
The High Pass Filter has two operating modes:
Off – If the High Pass Filter box is not checked the High Pass Filter is not
enabled.
On – If the High Pass Filter box is checked the High Pass Filter operating
mode is stereo and both left and right audio channels are treated equally by the high pass
lter frequency.
Metering
FM-55 / Aug 2014
The left side of the lower portion of the GUI shows
the ACTIVE INPUT metering, metering from clipping
depth and MPX clipping. The right side shows the left
and right digital AES output levels and the TX1 and TX2
composite output levels. The grid in the center is not used
in this tab but in other tabs displays critical information
relevant to that tab. You will see what can be displayed
in the grid as you move through the manual to set up the
processor.
page 3 – 13
EQUALIZER MENU
FM-55 GUI
This powerful 4‑Band Equalizer has four independent bands. Band 1 and 4 are shelving
lters while Bands 2 and 3 are fully parametric. The two parametric bands can be adjusted
in the following way:
Center Frequency — 20 Hz to 20 kHz.
Bandwidth — 0.2 to 3.0 octaves.
Boost/Cut — +/- 14.0dB.
The Band 1 Shelving EQ has a frequency range of 20‑500Hz and can have a boost or
cut of 14dB.
The Band 4 Shelving EQ has a frequency range of 2kHz to 20kHz and can have a
boost or cut of 14dB.
The controls of the equalizer may be manipulated in three ways:
1. The rst is by directly clicking on and dragging the control sliders in the parametric
equalizers control screen. As the controls are manipulated, numerical representations
of the control settings appear in the boxes below the band that is being adjusted.
2. The second method of adjusting the equalizers is by directly manipulating the
actual curves on the graphical screen using the mouse (the Enable checkbox must
be checked to turn the EQ on). See the next page for how to manipulate the curves
directly.
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FM-55 GUI
3. The third method is by direct value entry. By double clicking on the value boxes
underneath each slider, a dialog opens up which allows keyboard entry of the
operating values for each equalizer section. Once the value has been typed into
the entry box, clicking the OK button or hitting the keyboard Enter key will make
the value active. Note that the direct entry method is controlled by a lookup table
of all possible values. If an entry is made that is not in the lookup table, the closest
lookup table entry will be made active.
Manipulating Equalization Curves via Mouse
Double clicking on the small crosshair at the top (or bottom if it’s below the line)
of the curve turns that section on and off (white arrow)
Clicking on the crosshair and holding the left mouse button down as you drag the
mouse will move the curve to any frequency (left or right move) as well as adjust the
curve’s height above or below the 0dB reference line (up or down move).
Clicking on the small “tent” underneath (see red arrow), and holding the left mouse
button down while sliding the mouse left or right allows changes the bandwidth, or “Q,”
of the equalizer section.
EQ Enable
This is the master Equalizer In/Out button. When the Enable box is checked the
equalizer section is “IN”.
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FM-55 GUI
MULTIBAND LEVELLER MENU
The FM‑55 has two processing stages, the Intelligent Automatic Gain Control (iAGC)
and Multiband Leveller/Compressor. Both are linked by DSP algorithms which logically
connect and control them. Under normal operation, both stages should be active. However,
for sonic reasons or because of outboard processing, there may be a need to defeat certain
stages. That can be accomplished by unchecking the options in the upper left corner of the
GUI. Both sections will be collectively discussed in one chapter rather than separately.
A Word About Outboard Processors and Rreevveerrbb
Several popular outboard broadband and multiband pre‑processors on the market have
been used in front of “all‑in‑one” processors to achieve one or all of the following:
• A different sonic texture than what is available in the main processor.
• The ability to bypass functions in the main processor (usually located at a trans-
mitter) and bring the “meat” of the controls to the studio end for endless tweaking
• Compensation of a poorly designed AGC in the main processor.
• Overdrive protection for an STL path
• Encode level enhancement for ratings encoders.
We believe that the amount of control in our FM‑55 GUI allows the user to virtually set
the FM‑55 to whatever sonic texture they can think of, eliminating the need for an outboard
processor to emulate the same.
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FM-55 GUI
Internet connectivity allows processors in even the most remote locations to be
easily adjusted via a remote GUI. In most cases, the need for the processor to be at the
studio “…so it can be accessed…” is a thing of the past.
When audio levels in the plant are properly calibrated, there is no need for an AGC
in front of an STL path because almost all processional broadcast gear that may be
in‑line between the console and the STL will have as much if not more headroom than
the broadcast console. If non‑broadcast or semi‑professional gear is in the audio path,
it should be replaced.
There may be some cases where, no matter what, an outboard processor is needed
or desired and three of these situations follow.
• Ratings Encoders – We’ve found that ratings encoders need a “steady diet” of
incoming level in order to be function properly. Improper levels, especially those
that are too low, can be problematic for stations that are automated where a human
can’t make compensating adjustments to source levels on the console. While our
iAGC can easily compensate for audio levels more than 10dB different from source
to source, a 10dB drop in level at the input to the ratings encoder (which is prior
to the processing) will not keep a ratings encoder happy over the course of a 3‑4
minute song. It may even set an audio alarm and email and page the station’s staff.
The BEST way to address the level consistency problem in a facility is to make sure
there are standards in place for getting proper levels recorded into the playout system and
refrain from using outboard pre‑processors. Unfortunately, that isn’t always practical,
so if a station feels they must use outboard pre‑processing ahead of the FM‑55 we sug‑
gest bypassing the iAGC option in the FM‑55. The iAGC was meant to measure the
dynamic range in real time of the incoming audio, including any dynamic range issues
with board work or audio levels that did not match. If there is an aggressive leveling
device in front of the iAGC, it can alter the measurements and cause the iAGC to ght
with the pre‑processor.
• Reverb – Reverb was originally used as a way to increase modulation density
on older AM transmissions when the audio processing of the day simply wasn’t
sophisticated enough to do it. The effect of reverb not only did the trick, it also
added a pleasant sonic texture to the audio, one still desired by many stations
today. The challenge for most reverbs is that variations in their input levels can
have a very large effect on how they sound on the air if installed directly into the
program chain.
A pre‑processor is traditionally used ahead of a reverb unit which will protect it
from generating excessive reverb if (when) its input levels are too high. The use of a
pre‑processor ahead of a reverb also helps sustain the reverb effect.
As in the case of adding pre‑processing to boost encoding levels in a Ratings Encoder,
the same steps should be taken to adjust the FM‑55 to “mate” with the outboard
processor. If reverb is side‑chained into a microphone processor and not directly in the
audio path, and no outboard AGC is deployed, no special adjustments of the FM‑55
need to be made.
• Analog Telco STL or Aural STL – Older analog telco lines sometimes need
some pre‑processing in order to keep signal to noise ratios high. Some users have
indicated the need for pre‑processing before an aural STL to prevent overshoot.
Again, if you feel the need to use a pre‑processor in either of these situations,
adjustments to the FM‑55 should be made in concert with the suggestions above.
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FM-55 GUI
iAGC Controls
Gate Threshold
The iAGC Gate Thresh control sets the audio level at which
the iAGC gates (or stops responding to audio). The control can
be set to OFF to defeat the Gating entirely, or adjusted over the
range of ‑79.0dB to ‑20.0dB. There is also an OFF mode that
defeats the gate when it gets below ‑79.0dB.
iAGC Attack
Determines how quickly the iAGC will reduce the audio
level once a change is needed. The control has a range from 2.0
seconds to 7.0 seconds.
iAGC Release
Determines how quickly the iAGC increases audio once a change is needed. The
control has the same range as the attack control, 2.0 seconds to 7.0 seconds.
RTZ Enable
When active, allows the iAGC to return to unity gain in the absence of audio. The
unity gain value is ‑12dB.
RTZ Down
Sets the time the iAGC takes to return to unity gain when the iAGC is ABOVE unity
gain (between 0 and ‑12dB of gain reduction) whenever the audio falls below the gate
threshold. The range is 2.0 ‑ 7.0 seconds.
RTZ Up
Sets the time the iAGC takes to return to unity gain when the iAGC is BELOW unity
gain (between >‑12dB) whenever the audio falls below the gate threshold. The range is
2.0 to 7.0 seconds.
Multiband Leveller Controls
AGC Drive
The AGC Drive control adjusts the amount
of signal at the input to the iAGC and Leveller/
Compressor which then determines the depth
of gain control achieved. Driving the leveller
harder (higher drive numbers) results in a more
consistent on air sound along with an increased
ability to bring up low passages in program material when needed. Less drive creates a
more “gentle” on air sound which then has less capability to bring up low passages. The
range of this control is ‑12.0dB to +6.0dB.
Gate Delay
Delays the gate activation by a user dened amount of time once audio has fallen
below the gate threshold. The range is 50‑500ms.
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FM-55 GUI
Leveller Gate Mode
There are two different modes available for
tailoring the behavior of the Leveller Gate during
periods of silence or low audio levels when the
audio is below the currently set Gate Threshold.
When Ooze is selected and the audio input
falls below the Leveller Gate Threshold, rather
than the bands “holding” their current gains, their gains will slowly increase towards 0dB.
The Ooze setting is useful for formats playing material with very wide dynamic range or
for certain speech-based formats.
When Hold is selected and the audio falls below the Leveller Gate Threshold the gains
of the ve bands will “freeze” at their current values. Their gains will hold at those values
until audio is above the Leveler Gate Threshold again. The Hold mode prevents the
Leveller from increasing its gain in the absence of audio which minimizes the increase
of background noise.
Leveller Gate Threshold
The Leveller Gate Thresh control sets the audio level for when the Leveller enters one
of the Gated modes explained above. The control can be set to OFF to defeat the Gating
entirely, or adjusted over the range of -79.0dB to -20.0dB.
Crossover Frequencies
The Leveller/Compressor is a ve band design utilizing phase linear
Linkwitz-Riley crossover lters. Careful lter design eliminates un-
natural spectral coloration when deep gain reduction is occurring in
one or a few bands.
Crossover Frequency Options:
Band 1 to Band 2 – 50, 70, 90, 110, 130 Hz
Band 2 to Band 3 – 220, 300, 380, 460, 540 Hz
Band 3 to Band 4 – 800, 1200, 1600, 2000, 2400 Hz
Band 4 to Band 5 – 3500, 4500, 5500, 6500, 7500 Hz
Band Coupling (Inter-band Coupling) and Key Band
Each band of Leveller and Compression can be offset from its
neighbor by using the coupling controls. You can also select which
band can be the key or master band.
Each Band Coupling control may be adjusted over the range of
“0dB” to “-6dB.” When all the coupling controls are set to “0dB”,
only Band 2 can take on more gain than Band 3 (if Band 2 is the
key band). All of the other bands will remain “at”. If Band 3 is
the key band, it can take on more gain than Band 4 while all other
bands remain “at”. Such a setting is useful in formats such as
Classical and Jazz that typically would not enjoy the automatic
spectral balance “correction” that more processed formats usually
prefer.
In most programming situations the optimum setting of the coupling controls will likely
be somewhere between -1.0dB and -3dB for bands ABOVE the key band and -2.0dB to
FM-55 / Aug 2014
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FM-55 GUI
‑6dB for bands BELOW the key band. Decoupling the Leveller’s bands beyond ‑6dB
can allow their gains to “wander” too much, causing unnatural spectral buildup on some
material. Therefore the maximum decoupling is 6dB.
Multiband Leveller Dynamic Displays Menu
Each band has a compression threshold control which affects the operating threshold
of the Leveller and Compressor and that control is labeled Thresh in the graphic.
The lower region of the GUI allows the user to change the threshold and timing of the
ve band leveler and compressor. It also has options for compression ratio, mixer output
and stereo enhancement. For more information on how to use the button controls, please
see page 3‑8 of this Chapter.
The scale on the left side of the grid shows values of the ve dots as it relates to the
option that is chosen, which can be selected by clicking on the tabs above the grid. In the
example above, the Thresh (threshold) control is chosen and the scale on the left shows
the threshold level (in this case, all ve bands are at 0dB). If you were, to say, select
Comp Atk (compressor attack), you would see the left scale change to show the timing
values in milliseconds (ms) of the compressor as shown below.
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FM-55 GUI
The scale on the right side is static and shows the gain reduction of the 5 band leveler/
compressor and iAGC at all times.
Three gain values are shown in the lower region. There’s an orange at line and then
there are two additional lines (yellow and blue) that show the amount of gain reduction
in the 5 band leveler and compressor.
The orange at line represents the gain reduction of the iAGC (in the example above,
the iAGC is at ‑9dB of gain reduction). The yellow line is the fastest gain controller
active. The blue line is the Leveller when the leveller and compressor are active together.
On the left, when both the leveler and compressor
are active, the yellow compressor line “covers up” the
blue leveler line when the leveler and compressor are
at the same value of gain reduction. When the compressor needs to further reduce gain, you will see the blue
leveler line appear as the compressor adds more gain
reduction, as shown on the right.
The yellow and blue lines show each band of the 5 band leveler and compressor.
Watching the activity will reveal what is being displayed as the lines will look like they
are “stairs” and will move around and change shape based on the amount of gain reduction
in each band.
In the top example, the leveller and compressor have the same gain reduction values
across the board in each band (with Band 4 about to add more compression as the line
is starting to turn blue). Band 5’s gain reduction value is, at the moment, very similar to
Band 4. Compare that to the example below where Band3 has more compression than
leveler control and Band 4 is deeper into gain reduction than Band 5.
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FM-55 GUI
The controls along the top of the grid (outlined here in red) allow you to select the
parameter you wish to adjust. Those parameters are described below:
Threshold
The Thresh control determines at what level processing will begin to take effect in
a particular leveller band. Higher threshold settings cause processing to begin at higher
levels and lower threshold settings cause processing to begin at lower levels. The range
for the FM‑55’s AGC Threshold controls can be offset +/‑ 6dB from their 0dB reference
Leveller Attack
The Levlr Att control determines how quickly the leveller will respond to upward level
changes in the audio. The control range is 50ms to 500ms. A setting of 300ms corresponds
well to our perception of average loudness and is therefore a very good starting point.
Leveller Release
The Levlr Rls control determines the rate at which the Leveller will increase gain when
the audio levels fall, as long as they are still above the Gate Threshold setting discussed
previously. The adjustment range of the control is from 1.0 seconds to 7.0 seconds. The
7 second setting is considered VERY slow and is recommended for ne‑arts or classical
programming (or, if you’re Jeff Keith, for Classic Rock processing when he wants the
on‑air dynamic range to mimic the old AOR formats). The 1 second setting is very fast
and is recommended only if a certain “pumpy” texture is desired. The recommended
setting for most formats is between 2.5 seconds and 6 seconds.
Density
Adds energy into each band of processing to add consistency and loudness. The density
control range is 0‑6 with higher numbers adding more consistency to each band.
Compressor Attack
The Comp Atk control determines how quickly the Compressor responds to rising au‑
dio levels not caught by the Leveller because of its longer attack time. The compressor’s
purpose is to handle medium term peaks only, and by doing so it completely frees the
AGC from having to worry about controlling them.
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FM-55 GUI
Compressor Release
The Comp Rls control determines how quickly the compressor returns gain to the
processing “oor” established by the leveler’s current value of gain reduction.
The main purpose of the leveller is to provide a processing platform for the compressor
to work off of. The leveller will never allow the compressor to achieve more GAIN
as the leveller and iAGC is tasked with that duty, instead, the primary purpose of the
compressor is to catch any peaky audio the leveller misses because of its very slow,
averaging operation.
Ratio
The Ratio determines the how tightly the multiband processing in this section controls
the audio. The range of adjustment is from 2:1 to 6:1. The Ratio for each band may
be set individually, and the Ratio settings apply to both the Leveller and Compressor
simultaneously.
AGC Mix
The Mix control may be used to tailor the spectral mix of the processed signal. Very
dramatic EQ changes can also be made using these controls. Generally we recommend
that the AGC Mix controls be set at and the parametric EQ used for EQ tailoring. If
more than the parametric EQ is required, small changes can be made here if needed,
+/‑3dB at most, for best on‑air consistency.
Stereo Enhance
The FM‑55 contains a multi‑pronged stereo enhancement technique that has proven
to be very effective in the eld in other Wheatstone processors. This approach has a
side benet in that it minimizes receivers’ reactions to multipath interference without
degrading the audible stereo separation.
This multi‑pronged approach includes:
• Separate Difference (L‑R) mix levels.
• Overall post‑Multiband stage L‑R signal level manipulation.
• Automatic Multipath Limiter incorporated into the stereo encoder.
The Mix and Stereo Enhance controls can be used in combination to arrive at virtually
any style of stereo enhancement. For instance, after passing through a codec many
program sources contain extra midrange energy in the L‑R and because there is less
audio energy in that signal to mask such artifacts they can become more audible in
stereo. By slightly reducing the Band 3 and Band 4 L‑R Mix settings (perhaps 1dB to
3dB) these artifacts can be smoothed out and made less obvious.
To further mask such artifacts and/or to make the stereo sound eld big, wide, and
warm, one might slightly reduce the Band 3 and Band 4 Stereo Enhance levels while
FM-55 / Aug 2014
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FM-55 GUI
also slightly increasing the Stereo Enhance 2 Mix level. The Band 3 Band 4 settings
help subdue codec artifacts while the increase in lower midrange energy provides a
comfortably wide sound. Because high L‑R frequencies aren’t also being enhanced, the
susceptibility of receivers to the blending artifacts during multipath is reduced, giving
the audience in questionable coverage areas a better listening experience.
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MB LIMITER MENU
FM-55 GUI
The output of the iAGC/Leveler/Compressor directly feeds the ve band limiter.
The limiter in the FM‑55 was designed as a protection limiter between the dynamics
processing and the nal peak clippers. Unlike other inferior designs on the market which
require the limiter to limit, retain spectral balance, gate and build density, our limiters are
designed to ONLY limit, which is what a limiter should do. In the FM‑55, density and
spectral balance is achieved in the iAGC/Leveler and Compressor stages. That’s what
they are there for. The limiter works and sounds best when it just protects the clipper
from overshoot from the dynamics stage. That’s what it is there for!
Our limiters have no gating and should only be driven so that a few dB of limiting is
occurring. That’s it! You don’t want, nor should you NEED heavy amounts of limiting
when the previous stages of processing are designed correctly!
Limiters and Clippers Controls
Enable Limiters
The Enable Limiters button turns on or off the limiter
section. Under normal operation, this should always be
ON. If it is bypassed, audio is passed right to the clipper
without any limiting.
Multiband Limiter Drive
Drives the level into the ve band limiter. It’s important
to remember that the FM‑55 needs only a few dB of limit‑
ing to be loud yet amazingly clean! The drive control is +/‑ 12dB with 0dB being default.
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FM-55 GUI
Limiter Knee
Changes the knee of the limiter from soft to hard. When in HARD mode, the limiter
thresholds set in the controls of the Dynamic Display menu are absolute, limiting will
begin at the control settings. When in SOFT, gain reduction begin‑
ning to take place 3dB below a band’s
actual threshold setting with limiting
gradually getting harder as it reaches
threshold. In the soft mode, limiting is
more obvious but the audio can also be
smoother, especially on voice. In the
hard mode, limiting is less noticeable
but some peaky material may induce
clipping faster.
Bass Clipper Threshold
Sets the threshold level of the bass enhancer and clipper if the option
is selected. The range is ‑6dB to 0dB. Normal settings are around
‑3 to ‑2dB. Lower numbers (towards ‑6dB) will lead to more bass clip‑
ping and more controlled bass. Higher numbers (towards 0) will lead to
less bass clipping and less control of bass by the clipper.
Enable
Turns on and off the bass enhancer and clipper. The bass enhancer and
clipper can help to manage bass as a separate function of the main clipper. This allows
the end user to tailor bass a bit more freely without causing IM distortion in the main
clipper. When the bass clipper is off, bass is treated exclusively in the main clipper only.
Bass Style 2
By default, the bass enhancer is set to Style 1, which is suitable for most formats. If you
desire bass that is fatter and more prominent, try Bass Style 2 which widens the enhancer
in front of the bass clipper for a more “full sound” for Urban or CHR/dance formats.
Main Clipper Drive
This control is basically the output of the ve band limiter to the clipper.
Higher numbers yield louder audio with the traditional “loudness vs clean”
tradeoff. The drive should be between 0dB and +2dB for competitive formats
and ‑2dB to 0dB for classical or ne arts/talk programming.
Pre-Emphasis
Sets the pre‑emphasis curve to match what is required for your region
and transmission system. The options are Flat, pre50uS and pre75uS.
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FM-55 GUI
FM Diversity Delay
The FM‑55 is equipped with an internal digital delay to compensate
for the corresponding delay in the analog signal path of stations using
the HD Radio codec. The delay section is capable of providing up to
ten seconds of compensating delay in steps of 100 microseconds.
When the FM Diversity Delay controls are both set to their mini‑
mum settings, OFF appears in the delay window to signal that there
is no delay the FM signal path.
Use the following table to adjust the diversity delay and the SHIFT and CTRL keys
on your keyboard.
COARSE ADJUST SLIDER FINE ADJUST SLIDER
Slider Only 500 mS Slider Only 0.9 mS
Slider plus Shift key 1700 mS Slider plus Shift key 8.6 mS
Slider plus Ctrl key 50 mS Slider plus Ctrl key 0.1 mS
Note that the smallest increment of delay time adjustment is 100 microseconds.
Limiters and Clippers Dynamic Displays Menu
The lower region of the Limiters and Clipper page allows the
user to change the threshold and timing of the ve band limiter.
It uses the same button/dot adjustor scheme as the Leveller/
Compressor. For more information on how to use the button/
dot controls, please see page 3‑8 of this Chapter.
The right side of the lower region scale shows the limiter
gain reduction in dB. The left side of the lower region scale
shows the numerical value of the option being adjusted. For
instance, when Threshold is being adjusted, the left scale shows
the threshold level in dB. If Release is being adjusted, the left
scale shows the release times in dB.
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FM-55 GUI
Threshold
The Threshold control determines at what audio level
limiting will begin in a particular band. The limiter threshold
controls are adjustable +/‑6dB for each band. The absolute
threshold of each limiter band is determined not only by the
settings here, but also by the Multiband Mode (“Soft” or
“Hard”) as explained above.
Attack
This control determines how quickly the limiter bands
respond to audio peaks once they exceed the limiter threshold.
The range is 0.5ms to 50ms. Recommended settings are
between 5ms and 30ms. Longer attack times allow more of
the audio peaks to reach the clipper. Shorter attack times will
make the limiter more audible
Release
The Release time control determines how quickly the limiter will return to 0dB resting
value once audio has fallen below the limiter threshold. Faster release times will yield
a louder sound while slower times will yield a smoother sound at the expense of some
loudness resting value.
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STEREO GENERATOR MENU
FM-55 GUI
The Stereo Generator screen contains the controls required to congure the FM‑55’s
internal DSP‑based precision stereo generator and set the various output levels.
Mode
The stereo encoder may be operated in Stereo or Mono simply by select‑
ing the desired operating mode with this switch. In the Mono mode the stereo
pilot and subcarriers are completely turned off.
Test Oscillator
The built in test oscillator is capable of generating sine wave test signals
from 50Hz to 80kHz at modulation levels from 0 to 100% including a 31.25kHz
Bessel Tone useful for modulation monitor calibration checks. The oscillator
is on when the Enable checkbox is selected.
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FM-55 GUI
MPX Output Configuration
Composite Clipper Drive
A high ratio distortion managed clipper precisely controls peaks without
generating high order distortion or high subcarrier noise levels. The
composite clipper is available on the MPX outputs and the baseband192
AES over MPX output. The composite clipper is not available on the Left/
Right AES output. Normal operation range for the composite clipper is
0 to +2dB.
BS412 MPX Power Controller
The FM‑55’s BS412 MPX Power Controller can be set in 0.1dB
increments from +6dB to ‑3dB. When the control is in any position it is measuring and
controlling the current MPX Power level is shown on the BS412 meter in the GUI.
Calculated corrections to the MPX power are only made when the BS412 Enable check
box is checked, and when it is checked, modications to the MPX power will take place
immediately!
IMPORTANT!
The BS-412 MPX Power Controller’s sole purpose is to reduce loudness and
program density as required in certain European countries. If you are not required to use the BS-412 Controller do not check the BS412 check box. Turning
on the BS412 MPX Power Limiter can result in a signicant loss in loudness.
When the BS412 Enable check box is checked the MPX Power controller is then
engaged and the algorithm immediately applies the measured MPX Power correction to
the processed output. After the MPX Power Controller is rst engaged allow a full
minute for the MPX Power to settle to its nal value.
As the controller measures and integrates the MPX energy over time the drive to
the processing will be modied until the measured MPX power satises the reference
level as set by the Stereo Generator menu’s BS412 control. The control’s “0dB” setting
conforms to the current ITU‑R BS.412‑7 Multiplex Power standard.
Pilot Injection
The Pilot Injection control adjusts the level of the 19kHz stereo pilot and
is adjustable from 0 (Off) to 20% of the main composite signal amplitude in
0.1% steps.
Pilot Phase
Small corrections to the 19kHz stereo pilot phase may be made in 0.5
degree steps up to +/‑22.5 degrees. The ability to vary the stereo pilot phase
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FM-55 GUI
relative to the 38kHz subcarrier allows FM‑55 to compensate for nonlinear time delays
in the transmission system. Such time delays skew the phase relationships between the
19kHz stereo pilot and the 38kHz stereo subcarrier and degrade stereo separation.
MPX Output
The MPX #1 and MPX #2 level controls set the peak
output amplitude of the TX 1 and TX 2 outputs on the
rear panel BNC connectors respectively. These controls
are used to set total modulation in the presence of audio
and can be set to levels between ‑24dB and +6.00dB in
0.05dB steps. The control setting for approximately 3.5V
P‑P (1V RMS) into a 10k ohm load is +2.40dB.
If MPX #2 Pilot Only is checked, the MPX #2 output
becomes a 19kHz sine wave synchronizing source for RDS generators.
Multipath Limiter
The FM‑55’s Stereo Generator is equipped with a special algorithm called the Automatic
Multipath Limiter. This algorithm operates in the sum/difference domain and automatically
controls the amount of difference channel (L‑R) amplitude as a function of the instantaneous
sum channel (L+R) amplitude.
The purpose of this algorithm becomes clear when one realizes that a large amount
of L‑R is known to exacerbate FM multipath.
We said “exacerbate” because a high level of L‑R does not cause multipath. Rather,
the behavior of a stereo receiver as it blends between stereo and mono becomes much
more obvious when there is a large amount of L‑R in the decoded audio because of the
acoustical summation of L+R and L‑R energy in the listening environment. When the L‑R
signal “goes away” during a receiver blend the perceived audio level drops and the larger
the amount of L‑R present when such a blend occurs, the more noticeable the multipath
“event” will be to the listener.
When stereo enhancement is utilized in the program chain (or in the audio processor)
L‑R energy is naturally increased – this is the purpose of stereo enhancement – to exag‑
gerate the stereo image width by increasing the level of L‑R. When taken to the extreme
however the extra L‑R energy can cause either unnatural sounding audio on some program
material (the hole in the middle effect), odd behavior in many stereo receivers, or both.
Another issue is that in FM broadcasting, each dB of L‑R increase results in a like
decrease in level in the L+R sum channel and it is this signal that is responsible for mono
loudness. This is important to keep in mind when a fair percentage of the listening audience
might be listening on mono receivers!
In order to make stereo enhancement “play nice” with the majority of stereo receivers
in real‑world listening environments with all types of program material, it is preferable to
have some sort of controlling mechanism in place to “manage” the amount of L‑R energy
present in the transmitted signal as a function of program material. This is precisely what
the Automatic Multipath Limiter does.
There are eleven operational choices available under the Automatic Multipath Limiter
Threshold control settings: 10% to 100% in 5% percent steps, and an Off setting. Off is
the setting immediately above the setting for 100%.
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FM-55 GUI
When in the Off position the Stereo Width Limiter is completely out of the circuit.
When the control is at the 100% position the L-R may be permitted to achieve 100% of
the instantaneous L+R audio level. At lesser percentages the amount of L-R energy is
constrained to that percentage of the L+R level at that instant.
A recommended setting for this control is 70%, which constrains the L-R to about
3dB below the L+R. With the Automatic Multipath Limiter at this setting it will almost
never touch “normal” stereo program material – even when stereo enhancement is used.
This is in contrast to a control in another audio processor that has static settings for Stereo, -3dB, -6dB, and Mono. In that product, setting the control to -3dB causes a static
3dB reduction in stereo separation on all program material regardless of whether it needs
it or not. We believe our approach is better because it is intelligent. It does not decrease
stereo separation on program material that does not need it but, as you will see in a few
short paragraphs, it can help REDUCE separation, naturally, on over enhanced material.
Using the Multipath Limiter With Stereo Enhancement
Normally, one would not expect to want to add and, at the same time, want to RESTRICT
or REDUCE stereo enhancement. However, the FM-55, like all Wheatstone FM processors,
allows you to do just that. So, why would you?
Let’s say you want to enhance so you get some consistently wide stereo in the region
where the human ear will perceive it… between approximately 800Hz thru 3kHz. Now,
let’s say that your production guru likes to add ADDITIONAL stereo enhancement to their
production pieces. Or, you play some recordings (classic rock, oldies) that hard pan audio
between the left and right channels. Well, enhancement plus enhancement can sometimes
lead to… OVER-enhancement.
That’s where the multipath LIMITER comes in. Like an audio limiter keeps rising
audio levels from exceeding a xed level, the multipath, the multipath limiter can keep
a check on rising L-R levels.
At the end of the day, the stereo information transmitted by a typical FM radio station
is never fully recovered at the receiver. A good receiver will give us MAYBE 35-40dB at
1kHz? So why not manage your enhancement for REAL WORLD listening situations?
With the multipath limiter you can… and still maintain the illusion of stereo enhancement!
Analog L/R Output
Analog L/R Output Level
The Analog L/R Output Level control sets the absolute peak
output level after all processing. The front panel and remote GUI
bargraph meters display the peak output levels. The control has an
Off position and levels can adjusted in 0.05dB steps over the range
of -80.0dB to 0.00dB.
De-Emphasis
When DeEmp. is checked the appropriate de-emphasis is ap-
plied to the FM analog output according to any pre-emphasis which may be in effect. If
no pre-emphasis is being applied this check box has no effect.
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FM-55 GUI
PreDelay
When the PreDelay box is checked the analog FM output will always be sourced
ahead of the FM Diversity Delay.
Digital Output
Digital Output Level
The Digital Output Level control sets the absolute peak output level in dBFS after all processing. The control has an Off
position and levels can adjusted in 0.05dB steps over the range
of -80.0dBFS to 0.00dBFS.
Baseband192 and AES Modes
The Digital Output has two options for the type of output. The
rst is baseband192 (bb192). When set to bb192, the digital output XLR jack on the rear
of the FM‑55 carries the Wheatstone baseband192 AES over MPX digital composite
signal that is compatible with exciters designed to ingest a digital composite signal.
WARNING:
You should check with your exciter manufacturer to make sure
your equipment has the capability to ingest the baseband192 AES over
MPX standard before selecting this option. Interfacing the FM‑55 to an
non‑compatible exciter with this option selected can cause unwanted results.
Unlike traditional AES, baseband192 completes the nal phase of the all‑digital
airchain that is clean AND highly competitive. Baseband192 allows you to use the
composite clipper and stereo generator in the audio processor while the signal remains
in the digital domain. Previously, if you wanted to interface your audio processor with
your exciter using an AES signal, you needed to use the stereo generator in the exciter to
complete the airchain. With the bandwidth available in Wheatstone audio processors and
on the input of compatible exciters, it is now possible to interface a COMPOSITE signal
over AES between the processor and the exciter. The stereo generator is now BACK in
the audio processor, where it can work intelligently with the rest of the audio processing.
The FM-55 supports the traditional AES interface between processor and exciter.
By selecting AES3, the output appearing on the rear XLR connector is a standard AES
L/R signal that can interface with STL systems or exciters that have AES input options.
WARNING:
If your exciter has the option for AES over MPX (baseband192) but you
require or desire to use a traditional AES interface, make sure your exciter
and the FM‑55 have compatible settings. Mismatching the settings between
the exciter and the processor can cause unwanted results. You should consult
the user manual for your exciter or contact the manufacturer for information
on conguring your exciter for the correct mode.
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FM-55 GUI
De-Emphasis
When DeEmp. is checked the appropriate de-emphasis is
applied to the FM digital output according to any pre-emphasis
which may be in effect. If no pre-emphasis is being applied this
check box has no effect.
PreDelay
When the PreDelay box is checked the digital FM output
will always be sourced ahead of the FM Diversity Delay.
Sample Rate
Select the system’s sample rate frequency: 48kHz or 44.1kHz.
SCA Inputs
Inputs applied to the SCA connectors are high pass ltered
to reduce hum and then low‑pass ltered at 94kHz before being
digitized at 192kHz. The SCA #1 and SCA #2 gain controls set the
SCA injection levels and can be set to OFF, or to levels between
-80.0dB and +10.0dB and in 0.05dB steps.
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page 3 – 33a
FM-55 GUI
SYSTEM MENU
The System screen allows system‑wide settings to be congured, such as how the GUI
communicates with the hardware and security settings within the processor.
Input/Output Settings Change With Preset
When this box is unchecked, recalling presets ignores the settings
of the input and output level controls and other system controls as‑
sociated with those functions. The following are considered to be
FM‑55 system, or global, parameters, which are saved with presets
but not restored when presets are taken, unless the Input/Output
Settings Change With Presets check box is checked. When this
box is checked, the following control settings are recalled whenever a preset is recalled:
From INPUT Menu:
• Analog Input Gain
• Digital Input Gain
• Left/Right Balance
From Stereo Generator Menu:
• Pilot Injection Level
• Pilot Phase
• BS412
• Analog Output Level
• Digital Output Level
• SCA #1 & SCA #2 Injection Levels
• Pilot Only
• TX 1 & TX 2 Levels
Wheatstone recommends that this option remain unchecked unless you have a need
to change any of the above settings when a new preset is taken. When this option is NOT
selected, the parameters listed above remain static between presets and only the sound
adjustments are changed.
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FM-55 GUI
Metering Data Over TCP/IP
By default, the FM‑55 utilizes the UDP protocol for
transmitting metering data to the remote GUI (the TCP protocol
with its guaranteed accurate packet delivery is always used
for control).
In some situations UDP packets are blocked by Internet
Service Providers, and when this occurs the GUI can
successfully connect to the FM‑55 but there is no visible metering data. Unless one can
successfully convince the ISP to allow unsolicited UDP trafc on their network (doubtful)
the solution is to utilize VPN Tunneling (which encapsulates all packets into TCP) or
simply switch the FM‑55 and its GUI to use the TCP protocol for metering. When the
Metering data over TCP/IP box is checked the TCP protocol is used for transmitting
metering data instead of UDP.
System Status
The system status shows you the current hardware tem‑
perature (in degrees Celsius), the active input (indicated by
the “active” status), WheatNet‑IP info, and digital output rate.
The green dot next to the digital input indicates the presence
of an AES signal, whether that input is active or not. The same
applies to the analog input indicator. A green dot indicates
that audio is present on the analog side.
In this example, the temperature of the unit is 42.4 C, the
analog input has no audio (indicated by the red dot) and the digital input has lock and
is active (indicated by the green dot and the “active” status).
Security
Remote Login
When Remote Login is clicked, a password prompt box will open as
shown on the left. There is no default password in the FM‑55. If you are set‑
ting this up for the rst time, you can skip
the Password part and just enter the New
Password and Verify the new password.
Other options in this menu include
the ability for the PC to remember the
password for the processor, to hide the
password as you type it (with dots instead
of the actual characters) and the ability to
gang the password for both the processing
and output options.
When access is restricted, only the System tab will
be allowed to be viewed. If you try and access another
tab, you will be prompted to input the proper password
that covers the functions in that tab.
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FM-55 GUI
Front Panel
The FM‑55 front panel can be passcode protected if desired to prevent
unauthorized access. The desired passcode can be entered either through
the front panel Access dialog (see Chapter 2, page 2‑10) or via a remotely
connected GUI. The passcode must be four characters long and use the digits
0 through 9, creating 10,000 possible passcode combinations.
The System screen of the software GUI is equipped with a button labeled
Front Panel. Clicking on this button opens the dialog box shown, which
offers three front panel security options:
Disable Front Panel – Clicking on this choice turns off the ability to do all local
front panel navigation on the FM‑55 hardware. When selected, this option prevents
all front panel access leaving the only access via a remotely connected software GUI.
No Password Required – Clicking this option removes a front panel password if one
is already assigned and also makes the front panel accessible without using any passcode.
Password – Clicking this option prompts the user for a front panel passcode. If a
passcode is entered and one has never been assigned before, that passcode becomes
the front panel passcode and local access to front panel functions will require the use
of this passcode.
If a passcode had already been assigned to the front panel, entering a passcode in
this dialog will immediately change the front panel password to the one that was entered
via this GUI dialog.
If the front panel has been locked and the passcode lost or forgotten, local front panel
access can be regained by using the GUI to either assign a new and known passcode,
or remove an existing passcode by clicking the No Password Required option and then
clicking Ok.
Note that the hardware may also be unlocked by other, much less convenient means.
Please contact the factory for the procedure if it become necessary.
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FM-55 GUI
GUI Access
The system allows you to grant access at certain levels of permission in
order to control the privileges of those accessing the various features of the
FM‑55. Privileges are granted by Access Code, not by user type. In fact, user
types are created through the generation of access codes for those user types.
Examples:
• Suppose Access Code 0000 is created with Preset Takes being the only box checked.
This means that a user which has been assigned access code 0000 can only take
presets.
• Suppose Access Code 5678 is created with Preset Takes and Setting Changes both
checked. This means that a user with access code 5678 cannot only take presets,
but can also make changes to the settings within those presets. Note, however, that
because Preset Saves was not checked when this access code was created, that user
may make changes to a preset but may not save them!
GUI Lock
In the event that security has been enabled by conguring the GUI Access Code &
Permissions Dialog (above), then selecting GUI Lock will immediately lock the GUI on
the host PC, prohibiting access until it has been unlocked with the proper access code.
If the access code has been lost or forgotten you need to contact our technical support
at (252) 638‑7000 or email us at: techsupport@wheatstone.com.
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FM-55 GUI
Side Bar Region
To the right of the control area is a vertically disposed row of buttons.
We will explain each button in turn.
Preset
When left‑clicked, a dialog box appears, showing folders that
contain presets.
Double‑clicking on a preset brings it
immediately into use in the FM‑55.
The box stays open until deliberately
closed, allowing differing presets to
be double‑clicked upon readily in suc‑
cession. This is a very direct means of
comparing presets. It is important to
remember to save the present settings
as a preset before invoking others, or
they will be lost.
Note also that you can only take presets that are already
loaded in the FM‑55 from this dialog box.
Library
When the Library button is pressed a
window‑style dialog box appears containing
three panels. The large panel on the left shows
the presets currently stored on the FM‑55.
The upper right panel shows the preset
folders on the PC hosting the GUI, and the
lower panel shows the presets stored in the
folder chosen in the above panel.
Normal windows‑style drag‑and‑drop
functions allow presets to be freely moved
between the hardware and the PC and vice
versa. Note that when preset are moved this
way, it is copies of presets, not the presets
themselves which are moved. The original
preset always stays where it was stored last.
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FM-55 GUI
Locking Presets
Presets stored on the FM‑55 may be locked by the user to prevent inadvertent over‑
writing, renaming, or deletion. This is accomplished by opening the Preset Library by
clicking on the Library button in the GUI. Once the list of presets is open, the ones actually
stored within the processor hardware
itself will be visible in the left pane.
There are two ways to manage the
lock status of user presets:
• The rst method is by highlighting
a preset (single left click) and then
right clicking it to open a dialog box.
Among the options are Lock Preset
and Unlock Preset.
• The second method is by highlighting
a preset as above, and then clicking
the Edit option at the top of the Preset
Library dialog box to reveal the Lock
Preset/Unlock Preset options. Note
that these are user‑level lock options
and therefore cannot be used to over‑
ride the lock status of a factory‑locked
preset!
How to View Preset Changes
It is possible to visually compare two
different presets on the FM‑55 with a spe‑
cial feature called Preset Difference.
When the Library tab is opened, high‑
light any preset you’d like to compare with
the current preset running on the proces‑
sor. Then right click and select View and
Diff from the sub‑menu. You will see the
window on the right open.
Any parameter that is listed with a RED
background indicates a parameter that is
different between the preset running on
the hardware and the preset that has been
highlighted. Parameters which are not
highlighted have the same values between
the two presets.
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FM-55 GUI
Save
Clicking on the Save button opens a dialog box (shown on the left),
prompting the user for a name
for the preset being saved. The
preset will be saved into the
next available empty slot unless
another empty slot is chosen
by nudging the preset number
(Preset #) up or down. Note
that it is possible to save the present settings in over an existing and
unlocked preset and doing so erases the previous preset’s contents.
Factory presets are protected from being inadvertently overwritten.
Quick Save (QSave)
The FM‑55 has a unique feature to Wheatstone processors that allows instant compari‑
son of work in progress to a known reference, such as another preset, or some midpoint
while adjustments are being made. We call this feature QSave (for Quick Save).
In the Side Bar of the FM‑55 GUI you’ll nd three buttons, QSaveA, QSave B, and
B=A.
QSaveA and QSave B represent two temporary memory buffers that hold all current
FM‑55 processing settings as long as power is applied to the unit.
While QSaveA is highlighted green any adjustments that you make to controls on the
FM‑55 are being concurrently saved to temporary buffer A.
QSave B operates on buffer B and just like QSaveA its being selected is shown by a
green highlighting.
One way to use this feature is to compare the sound of a factory preset to changes
you’ve made to it without having to rst save it as a user preset. To do this:
• Recall the factory or user preset that you wish to adjust.
• Ensure that QSaveA is highlighted. If it is not, press its button to highlight it.
• Press the B=A button. This will copy the contents of QSave buffer A to QSave
buffer B. Now the contents of both A and B buffers are identical.
• Change some settings on the FM‑55 and they will automatically be stored in the A
buffer.
• Compare your changed settings to the recalled factory preset by pressing the QSave B
button.
• Compare those settings back to the factory preset by pressing QSaveA.
• When you are happy with your changes you can commit them to a user preset using
the preset Save dialog explained previously.
Likewise, QSaveA and QSave B can be used to compare the sounds of two different
sets of user settings. To do this:
• Load the preset that you want to change, make changes to it, and press QSaveA to
save those settings to buffer A.
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FM-55 GUI
• Make some additional changes and then press QSave B to save
those additional changes to buffer B.
• Now buffers A and B have your two different settings you can
compare them by toggling back and forth between QSaveA and
QSave B.
• When you are pleased with one set of settings and need more
buffers for further tweaking, you can use the A=B/B=A button
to make the two buffers the same and have one of them to use to
start comparing from again.
Devices
Clicking on the Devices button opens a list
of the FM‑55 devices known to the GUI (if any).
Highlighting the desired FM‑55’s name and hit‑
ting Select causes the GUI to attempt to connect
to it if you are Online.
In the event there are no FM‑55’s are listed
yet, or a new one needs to be added, clicking the
Add button brings up a small Edit Device dialog
box which asks for the new prospect’s name and
IP address.
Headphone Source
The headphones may be driven by a number of selected points
inside the signal processing chain as follows:
Input: Output of the audio input selector, analog or AES.
Ana Inp: Audio appearing on the analog line input.
Dig Inp: Audio appearing on the digital input, whether it be
WheatNet‑IP or AES3 .
FM Out: FM output of the processing chain.
NOTE: The FM‑55 headphone routing selector allows you to monitor an unselected
audio input without having to put it on the air. This can be handy for conrming that an
audio source is present without actually switching to it!
Headphone Control
On the left side of the front panel of the FM‑55 is a quarter inch
female TRS jack for headphone use. The volume control for the head‑
phone output is located on the lower right side of the GUI.
To adjust the headphone volume slide the fader right to increase
volume and left to decrease it.
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FM-55 GUI
Title Bar Region
Along the top edge of the FM‑55 GUI screen (in line with the Wheatstone FM55
product label to the left, and the Windows About, Minimize, and Exit icons to the right)
are indicators and controls for the management of devices and presets. The FM‑55 GUI
is capable of controlling multiple FM‑55 units (Devices) and managing the presets within
them. Whether a connection is made (Status), and which device and which preset are
presently under command are indicated.
Status
This indicator shows four different statuses:
Online – The GUI is in communication with an FM‑55.
Ofine – The GUI and FM‑55 are disconnected.
Trying – The GUI is attempting to nd the FM‑55 on the LAN and connect to it.
Pending – The GUI has found the FM‑55 and is trying to complete the connection.
An adjacent and illuminated button toggles between Online and Ofine.
Device
The name of the FM‑55 to which the GUI is connected (or with which it is attempting
to connect) shows in the Device window in amber text.
Double‑clicking on the name area
brings up the Devices dialog box. A list
of FM‑55 devices that the GUI knows
about is shown in the box. Highlighting
the desired FM‑55’s name and hitting
Select causes the GUI to attempt to
connect to it if the Online/Ofine but‑
ton is green (Online).
In the event no FM‑55 units are
listed, or one is adding a further device,
or one for the rst time, Add brings
up the Edit Device dialog box, which
asks for the new prospect’s name and
IP address.
Current Preset
The Current Preset window shows the current preset that is active on the processor.
When the preset name is displayed in GREEN text the currently running preset reects
exactly what has been last saved to that preset and that no changes have been made.
When the preset name is showing in RED text, the current preset has been modi‑
ed and is not saved on the FM‑55 hardware. In order to return the preset name text to
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FM-55 GUI
GREEN, the modied preset must be saved, or
a new preset has to be retaken from the list of
saved presets.
As covered earlier (page 3‑39), it is possible
to visually compare two different presets on
the FM‑55 with a special feature called Preset
Difference.
Double‑clicking on the name brings up a
Preset Difference – parameter‑by‑parameter,
setting‑by‑setting – comparison list between the
current FM‑55 settings and the recalled preset.
Any parameter that is listed with a RED
background indicates a parameter that is different
between the preset running on the hardware and
the preset that has been highlighted. Parameters
which are not highlighted have the same values
between the two presets.
Notes on Online and Offline Working
Often it will be required that the GUI act directly and instantaneously upon the FM‑55
when a preset is selected. This is the Online mode.
Ofine, however, is more of a management utility intended for creating presets or
tweaking them without needing to listen to them on the host FM‑55.
Changes can be made to presets and congurations without affecting the sound of the
processing occurring within the FM‑55.
Importantly, any adjustments made on the GUI Ofine will not take effect until the
preset changes have been saved, the FM‑55 is Online to the GUI again, and the preset is
made active by selecting it.
Invoking a preset – by double‑clicking a preset from the box brought up by clicking
the Presets button – does one of two things, depending on whether the GUI is in Online
or Ofine mode:
• Online – the double‑clicked preset is immediately sent to the FM‑55 and becomes
active.
• Ofine – the double‑clicked preset brings that preset onto the main control and
display screen for perusa l/editing. Any data entry /control which involves activity
within the main graph will still operate upon the preset, but not on the FM‑55’s audio.
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FM-55 GUI
Accessing Menu Options
Right clicking anywhere on the FM‑55 Control Panel will open a pop up menu tree
with access to File, Hardware, and Presets choices. These choices lead to sub‑menus
and dialog boxes that may also be accessed by clicking on other dedicated buttons on
the main FM‑55 control panel. As with many Windows programs, the GUI has multiple
ways to access menu trees – go ahead and explore!
File Menu Items
The File menu tree may be accessed by right clicking
anywhere on the main FM‑55 Control Panel.
About – Brings up the About box to indicate the GUI’s
software version. Note this is not where the rmware versions
running on the hardware are polled. That is done under the
Hardware option covered in a moment.
Choose Skin... – Brings up the Choose Skin dialog box. In some GUIs there are mul‑
tiple skins available which allow the user to pick different color schemes and such. Not
all GUIs have multiple skins but many do.
Exit – Closes down (exits!) the entire GUI (not just the dialog window).
Hardware Menu Items
The Hardware menu tree may be accessed by right
clicking anywhere on the main FM‑55 Control Panel.
Please note that most of the Hardware‑related items
require you to be connected (Online) to the FM‑55
because that is where the data must come from. Sub
menu choices include:
Devices... – Opens the Devices dialog box. Al‑
lows the creation, editing, selection, and deleting of
Wheatstone processors connected to your system.
On-Line Mode... – Toggles between ONLINE and OFFLINE modes. This is the state
the GUI will assume the next time it is started. This state is also remembered when the
GUI is closed – if it was online to FM‑55 at the time it will attempt to go back online the
moment the GUI starts up next.
Login Password... – Opens the Passwords dialog box for editing login passwords.
Version... – Displays the current software and rmware versions running in the FM‑55
hardware.
Update... – Opens the Choose a le to download dialog box. Only valid les of type
*.rbn are visible. See below.
Reboot... – Sends a remote command to restart the FM‑55. NOTE: Rebooting will
take you off the air for 20‑30 seconds!
FM-55 Hardware Update
New or updated FM‑55 software may be released at any time to implement new
features, change specications, or correct known bugs. The Hardware Update choice
will open a separate dialog box which will prompt the user for the correct le type to be
uploaded to the FM‑55. Upon completion of the update you will be asked to restart the
FM‑55 (cycle its power).
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FM-55 GUI
The FM‑55 is extremely easy to update when new rmware becomes available from
Wheatstone. The update le is a “.RBN” which is packaged with a new GUI.
Before performing updates to the FM‑55 make sure an auxiliary processor is available
for when FM‑55 needs to be rebooted after the upgrade as there will be approximately
30 seconds of silence until FM‑55 reboots. Alternately perform the upgrade at a time when
you can temporarily remove audio
from the air without it being an issue.
To update the FM‑55, right click
on any portion of the control area
in any screen of the remote GUI to
open pop up menu tree. Select the
Hardware and then Update… option.
The screen at right will appear.
Navigate to the location of the
RBN le that was downloaded from
the Wheatstone Processing website
or if a new GUI version was just in‑
stalled, the RBN that was unpacked
during its installation. Verify that
the version number is correct in
that it matches the version number
listed in the documentation about
the rmware upgrade. If so, select
the Open option in the Choose a le
to download window. The prompt shown at right will
appear with wording of the text varying according to
versions to be uploaded.
Recheck that the versions match the documentation!
Then click Yes .
Progress boxes will pop up as the download progress
occurs:
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FM-55 GUI
When the system has nished downloading, you will get a prompt to reboot the
FM‑55. This can be done by removing and restoring power or by sending the reboot
command from the GUI.
After the FM‑55 reboots the new RBN code will be running on the motherboard.
If you have any questions about an update, feel free to contact Wheatstone Technical
Support at techsupport@wheatstone.com.
Presets Menu Items
The Presets menu tree may be accessed by right clicking
anywhere on the main FM‑55 Control Panel.
Take... – Brings up the Take Preset dialog box.
Save – Brings up the Save as Presets dialog box.
Library... – Brings up the Preset Library dialog box.
These dialogs replicate those accessible using the so‑labeled
buttons on the GUI itself. The right click menu structure is
simply another way to get there from here…
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APPENDICES
Appendices
Appendix A
General Specifications ..................................................................A-3
Appendix B
Interpreting Common Audio Processing Terms .........................A-8
Background ................................................................................................................A-8
Audio Terms and Wheatstone Processing .................................................................A-9
Thump/Rumble/Bottom ...........................................................................................A-9
Punch/Boom/Tubby/Warm .....................................................................................A-10
Mud ........................................................................................................................A-10
Honk .......................................................................................................................A-10
Whack ....................................................................................................................A-10
Fuzzy/Tinny ............................................................................................................A-11
Sibilance .................................................................................................................A-11
Treble/Bright/Open .................................................................................................A-11
Finally .....................................................................................................................A-12
Appendix C
WheatNet-IP Configuration ..........................................................A-14
Adding FM-55 to The WheatNet-IP System ..............................................................A-14
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APPENDICES
Appendix A
Contents
General Specifications ..................................................................A-3
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APPENDICES
General Specifications
Analog Line Input
Type: Electronic Differential
Impedance: > 10Kohm (bridging)
Optimum Source Impedance: < 1Kohm
A/D Converter: AKM5394. 192kHz, 24-bits
Minimum Input Level: +20dBu
Digital Line Input
Data Standard: AES/EBU (AES3)
Data Amplitude: Per AES3-2003 assuming minimum
allowable output signal amplitude of 2V
and minimum allowable input signal
amplitude of 200mV
AES Receiver: CS8416, 192kHz, 24-bits
Type: Wheatnet-IP
Data Type: 100 BASET Ethernet Network Compatible
Sample Rate: 32kHz - 96kHz (auto selected)
Input Reference: Variable between -32dBFS to -8dBFS
Input Gain Adjustment Ranges
Gain Range +/-12dB
Gain Adjustment Resolution.: 0.5dB
Gain Calibration: A gain control setting of 0.0 aligns an external
0dBFS signal with the FM-55’s 0dBFS
internal reference
Input Failsafe
Type: Automatic
Analog Fail Cause: Audio level below -42dBFS (xed)
Response Time: 30 seconds (xed)
Digital Fail Cause 1: Audio level below -42dBFS (xed)
Response Time: 30 seconds (xed)
Digital Fail Cause 2: Corrupted or invalid AES data
Response Time: Immediate (xed)
Failsafe Direction: Digital to Analog/Analog to Digital
(no Digital to Digital)
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APPENDICES
Audio Level Balance
Type: Common to both Analog and Digital inputs
Analog/Digital L/R Balance Range: +/-12dB
Control Resolution: 0.5dB
Voice Symmetry via Phase Rotation
Operating Modes: In/Bypass
Filter Type: 4
th
Order All-pass
High-Pass Filter
HPF Filter Class: 24dB/octave Butterworth
Frequency range: 20Hz – 300Hz
Parametric Equalizer
Section: Four
Frequency Range: 20Hz – 20kHz
Bandwidth Range: 0.2 – 3.0 octaves
Boost /Cut Range: +/- 14.0dB
Options: Bypass
5 Band Leveller/Compressor with iAGC
Drive Gain Range: -12.0dB to +6.0dB in 0.5dB steps
AGC Backoff: 0dB to -6dB
AGC/Compressor Thresholds: Offset +/- 6dB from reference
AGC Threshold Backoff (per band): 0dB to -6dB AGC
Leveller Attack: 50mS to 1 sec
AGC Release: 1000mS to 7000mS
AGC Band Coupling: 0dB to -6.0dB per band to key band
Compressor Attack: 10mS to 50mS
Compressor Release: 50mS – 1000mS (1 second)
Compressor Ratio: 2:1 to 6:1
L+R Mixer: +/- 6dB Boost/Cut
L-R Mixer: +/- 6dB Boost/Cut
Gated Modes: Ooze/Freeze
Gate Threshold Range: -20.0dB to -79dBFS, plus OFF
iAGC Attack: 2 to 7.0 seconds
iAGC Release: 2 to 7.0 seconds
RTZ Down: 2 to 7.0 seconds
RTZ Up: 2 to 7.0 seconds
Options: Bypass iAGC, Leveler or Compressor
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APPENDICES
Crossover Frequencies
Super Low to Low Band: 50-130Hz
Low to Low Mid Band: 220-540Hz
Low Mid Band to High Mid Band: 800-2400Hz
High Mid Band to High Band: 3500Hz-7500Hz
Band Output Trims, Sum: +/- 6dB
Band Output Trims, Difference: +/- 6dB
FM Peak Limiter
Multiband/Drive: +/- 3dB
Bass Clipper Threshold: -6 to 0dB
Bass Clipper Options: Enable, Bass Style 2
Main Clipper Drive: +/- 3dB
FM Pre-emphasis Modes: Flat/50µS/75µS
FM De-emphasis Modes: Follows selected pre-emphasis
Multiband Knee: Soft/ Hard
Multiband Threshold: +/-6dB relative to Drive
Multiband Attack: 10ms to 50ms (this is not a misprint)
Multiband Release: 3ms to 300ms (this is not a misprint)
FM Diversity Delay: OFF to 10 seconds, 100µS increments
Stereo Generator
Reference grade Stereo Generator with embedded Composite Processing, Test Oscillator,
SCA digitizer, and composite analog output or digital baseband192 output.
Composite Processor: Oversampled Clipper
D/A Conversion: 24 bit
MPX Processing Drive Range: +/-3dB
Automatic Multipath Limiter: 10% to 100% in 10% steps, plus Off
19kHz Stereo Pilot Injection: 0-20%, 0.1% steps
19kHz Stereo Pilot Phase: +/- 22.5 degrees referenced to 38kHz
SCA 1 & 2 Input: Analog, 10Kohm input impedance
Maximum SCA Input Level: +24dBu
Digital Output Trim Level: -48dBFS to 0dBFS
Digit al Output Options : L/R, L/R de-emph, L/R pre-delay, baseband192
TX 1 & 2 Output Standard Level: 3.5V P-P (1V RMS)
TX 1 & 2 Maximum Output Level: 8V P-P into 1kohm (+12dBu)
38 kHz Suppression 70dB or better @ 75kHz deviation
Pilot Protection: >60dB at 9% injection
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APPENDICES
Pilot Stability; >1.0 Hz
Pilot Level: Adjustable 0-20% injection
57kHz protection: >55dB @ 4% injection
Signal to Noise Ratio: >85dB
Total Harmonic Distortion (THD): <0.02
Stereo Separation: >55dB
Crosstalk: >70dB (main to sub/sub to main)
Analog Audio Outputs
Analog L/R Outputs: 48dBFS to 0dBFS
Analog Output Options: De-emphasize, pre-delay
Maximum Output Level: +20dBu
Signal to Noise Ratio: >80dB
Total Harmonic Distortion: <0.02% 20Hz to 15kHz
L/R Crosstalk: >75dB 20Hz to 15kHz
D/A Conversion: 24 bits
AES Output
AES Output Level: -48dBfs to 0dBfs
Digital Output Options: De-emphasize, pre-delay, AES3 or baseband192
Maximum Output Level: 0dBFS
Sample Rate: 44.1kHz or 48kHz user selectable
Signal to Noise Ratio: >100dB
Total Harmonic Distortion: <0.02% 20Hz to 15kHz
Test Oscillator
Frequencies: 50Hz to 80kHz plus 31.25kHz Bessel
Output Level: 0 to 100% in 1.0% steps
System
Headroom Level: >20dB
Nominal Operating Level: -20dBFS digital
Processing Latency: 9mS maximum – all features engaged
Total Harmonic Distortion: <0.1%, 20Hz – 20 kHz *
Intermodulation Distortion: <0.1% SMTPE *
Signal to Noise Ratio: >85dB *
Signal Chain Internal Dynamic Range: >144dB
Stereo Separation: >50dB (FM)
Crosstalk: >50dB, 20Hz – 15kHz *
Power Requirements: 100-250 VAC (auto sensing)
50/60Hz, 100 VA Max.
* Bypass Preset, unity gains, and 75µS pre and de-emphasis
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APPENDICES
Power Connector: EMI suppressed IEC male
Shipping Weight: 15 pounds
Operating Temperature: 0 to 50 degrees C (32 to 122 degrees F)
Overtemp alarm reporting via GUI
Allspecicationssubjecttoimprovementorchangewithoutnotice.
Preset Management
The FM‑55’s advanced preset management system allows the creation, storing, and
recallof80presetswithintheFM‑55itselfandanunlimitednumbermaybestoredonthe
WindowsPChostingtheGUI.Inadditiontoprocessingparameters,allSystemparameters
arestoredwithinpresetsallowingthepreservationofthecompleteprocessing“environment.”
Optionally,InputandOutputsettingsmaybestoredandrecalledwithpresets.
Preset Encryption
PresetsareencryptedusingtheFM‑55internal32bitserialnumberastheencryption
key.
General Purpose Interface (GPI)
TheFM‑55isequippedwiththeabilitytohaveGeneralPurposeInput/Outputclosure
viaRJ‑45suppliedontherearoftheunit.RefertoChapter1page1‑14fordetails.
Ethernet Interface
TheFM‑55containsanauto‑sensing100BaseTEthernetswitchwithoneportavailable
ontheoutsideoftheunitforelduse.Becausetheswitchisauto‑sensingitisnotnecessary
toutilizeacrossovercablewhenconnectingaPCdirectlytotheFM‑55.
Software Remote Control
Supplied Windows® FM‑55 GUI software affords control of all system and processing
parametersviaa100BaseTEthernetinterface.
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page A – 6a
APPENDICES
Appendix B
Contents
Interpreting Common Audio Processing Terms .........................A-8
Background ................................................................................................................A-8
Audio Terms and Wheatstone Processing .................................................................A-9
Thump/Rumble/Bottom ...........................................................................................A-9
Punch/Boom/Tubby/Warm .....................................................................................A-10
Mud ........................................................................................................................A-10
Honk .......................................................................................................................A-10
Whack ....................................................................................................................A-10
Fuzzy/Tinny ............................................................................................................A-11
Sibilance .................................................................................................................A-11
Treble/Bright/Open .................................................................................................A-11
Finally .....................................................................................................................A-12
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APPENDICES
Interpreting Common Audio Processing Terms
Background
When tasked with adjusting audio processing one is often faced with myriad meanings
for the same sound descriptors. When the program director comments that it needs more
“thump,” what does he really mean? If he says that the audio is too “crunchy,” what is
he hearing? Or if he says that the competition is nice and “bright” and they have some
nice “rumble,” what exactly is that? Or what if he wants more bass and you add some
bottom end but now he says “we sound too muddy”? How do we untangle this and get to
the bottom of what the PD really means?
Lots of “audio” terms regarding audio processing have been invented and bandied
about over the years. Ever since radio stations started employing circuits instead of humans
to control the modulation of transmitters we’ve tried to come up with words to describe
the effects of processing and what we hear. Many of these terms were born out of simply
trying to put into words the positive and negative artifacts of early compressors and limiters
(thump, muddy, honk, tubby). Still others were born later when EQ and different forms
of “enhancers” were added to audio chains and audio processors to exaggerate certain
parts of the frequency spectrum (rumble, punch for bass; bright, airy, open to describe
presence and the high end).
The language of audio processing more often than not needs the benet of an interpreter.
Some oft-used terms can easily have multiple meanings and be confused with others.
Some of the terms we use simply don’t describe very well what is actually happening to
the audio. For instance, one listener might feel the audio is “muddy” while another one
still might describe it as “warm.” Which one is right? For starters, “muddy” is not usually used in a positive sense, while warm, on the other hand, often means the sound has
a pleasing low end. See the confusion here?
The terms themselves, the ones that we use to describe sound, can be confusing enough.
The real question then becomes, what do these terms really mean, and which knob do
we turn if we want to change the sound? In fact, here is a very common challenge: if the
audio is too “muddy,” do you turn up the high end, or do you reduce the low end? Which
control is the right one if you wanted to bring up some low end “rumble” or “sub bass”?
And here’s another one; if the audio is “tinny,” is the problem that there’s too much energy
up around 8,000Hz or is the problem actually further down in the spectrum?
We’ve created a graphic to try to bring some understanding to the more common terms
we broadcasters use to describe sound and where these sounds actually reside in the audio
frequency spectrum. While creating an exhaustive list isn’t impossible, it is well beyond
the scope of what we’re trying to accomplish here. What we’ve done instead is compile
the terms we most commonly hear customers use, and then lay them out in graphic form
to help visualize what sounds live in what part of the audio spectrum we hear.
Included in the chart below are the frequency ranges of the most common instruments
heard in compilations played on the radio. The idea here is to marry musical instruments
and their sounds with the terms we all use. One good example might be the term “Honk,”
which coincidentally happens to be right in the middle of the frequency range created by
saxophones. The goal here is simple; offer a better understanding of how to adjust an audio processor so that the “thump” you want will be the “thump” you get and not “tubby.”
Please note that some of the controls mentioned on the following pages may not be
available on the FM-55. The discussion is generic to a wide variety of Wheatstone processor models.
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APPENDICES
Common audio processing terms and the parts of the spectrum
they govern are at the bottom of the chart. The top part of the chart
shows the frequency range of common musical instruments heard
on the radio (male and female voice included)
Audio Terms and Wheatstone Processing
So how do you tweak a processor to change its sound “texture”? Let’s start with the
low end…
THUMP/RUMBLE/BOTTOM
These terms describe bass generally found at and below about 80Hz. Good stereo
systems, closed or noise reduction headphones and car audio systems with subwoofers
can usually reproduce the audio way down here. Many times such systems even have their
own complex bass enhancement features. The FM-55 is equipped with a very specialized
bass clipper system. This system is an intelligent clipper that samples the bass frequency
relationship between bands 1 and 2 and is able to make changes to the audio based on
user settings in the ve band section as well as the ve band limiter.
The bass clipper has a threshold control as well as a style control. This allows you to
select if the bass clipper primarily focuses on Band 1 or when “Bass Style 2” is selected,
both Band 1 and 2. Moving the threshold control clockwise raises the bass clipper
threshold and allows more bass through to the main clipper. Conversely, moving the control
counter-clockwise puts more clipping into the control of the bass clipper.
Other ways of enhancing lower frequencies would be to set the Band 1 to Band 2
crossover at 50Hz or 60Hz in the leveler/compressor section and raising the threshold
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APPENDICES
of Band 1. This will allow very low bass to pass more freely through the leveller and
compressor section, with the lower bands of the limiter and the bass clipper managing
the rest.
PUNCH/BOOM/TUBBY/WARM
The sound of bass “punch” and “boom” usually fall in the range of 70Hz to 150Hz.
“Tubby” on the other hand usually falls between 150Hz and 300Hz. Band #2 of the
parametric Equalizer may be used to gently and broadly boost audio in the range of 75Hz
to 120Hz to safely reinforce the “punch” and “boom” of lower bass without creating
undesirable effects such as “tubbiness.”
The enhancement of “punch” and “boom” can be especially tricky because many
listeners’ sound systems don’t have the ability to reproduce lower and sub bass
frequencies. Therefore it’s especially important to use several known reference systems
when adjusting the enhancement of very low frequencies because it is easy to create
distortion or “muddiness.” How many stations have awesome sounding bass on the PD’s
car stereo but end up sounding terrible on clock radios and boom boxes? Always listen
on multiple radios in multiple listening environments to get the best feel for the effects
created by purposeful bass enhancement.
MUD
When someone says that audio is “muddy” they usually mean too much energy is
in the 250Hz to 400Hz range. Sometimes it’s caused by a misadjusted Equalizer or
a processor maladjustment that is allowing a leveller or compressor band to add too
much gain. In most cases it’s a good idea to keep from boosting energy in this region.
In fact, additional clarity and detail can be created by a broad equalization cut in the
range between 180Hz and 400Hz. This surprising little secret can be more effective
at “adding” detail in low bass and midrange than adding equalizer boost at the same
frequencies. It’s true! Try it!
HONK
Think Saxophone. Honk is above “mud” but below “fuzzy” and “tinny.” Honk oc-
curs between about 400Hz and 1,200Hz and begins to overlap “fuzzy” and “tinny” at
around 1000Hz. Usually audio in this range stands out on its own in the mix and any
enhancement should be slight because our ears are already very sensitive to these frequencies. This frequency range is also quite delicate because much of the perceived
stereo sound eld width also occurs in this range. When audio has a “honk,” “fuzzy,”
or “tinny” texture (and it’s usually a texture that one DOESN’T like), faster attack times
in the Compressor for that frequency band can help smooth things out. Another trick is
to relocate the Band 3 to Band 4 crossover to around 2,000Hz which allows Band 3 to
better manage any “harshness” that might tend to pop out on certain material.
WHACK
This is the sound where percussion just “explodes.” First, note that this is much
less of an equalization issue and much more about creating a temporarily dense sound
by momentary fast compression. To achieve more “whack” it can help to speed up the
Leveller or Compressor release times in Band 3. Another trick is to slow down the attack
time of the Band 3 leveller which will allow the Band 3 compressor to be more active.
This will enhance “whack.”
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APPENDICES
FUZZY/TINNY
Yes, “fuzzy” and “tinny” really are this far down in the audio spectrum! A “tinny”
sound might be described by some as a harsh midrange or too much presence instead
of something happening higher up in the audio spectrum. Both “fuzzy” and “tinny” live
between about 1,200Hz and 2,000Hz. One of the best ways to manage either is to broadly
and slightly reduce equalization in this range, or even increase the attack time in Band 3
of the Leveller and Compressor.
Sometimes there is a tradeoff between getting more “whack” and keeping “fuzzy/
tinny” at bay. Speeding up the compressor in the 1,000Hz to 1,500Hz range to get more
compression “whack” can sometimes add undesirable side effects, one of which is the
creation of what sounds like “fuzzy,” “dense,” or even “tinny.” In audio processing, especially broadcast audio processing, everything is a tradeoff. While Wheatstone processors
provide the most wiggle room for getting the sound you hear in your head on the air,
sometimes compromises will need to be made.
SIBILANCE
Sibilance is a vocal artifact and because it sounds so unnatural it tends to stick out
like a sore thumb. Excessive sibilance can be the result of too much high-end boost or
too much nal clipper drive. Sibilance tends to be most prevalent in the 4,000Hz to
8,000Hz portion of the frequency spectrum. Microphone processors (like the Wheatstone
M1 and M2) are great tools for keeping vocal sibilance under control. Their specialized
de-esser sections are specially tailored for removing or minimizing excessive “esses.”
When excessive sibilance is an issue and there is no microphone processor to control it,
lowering the FM-55’s Band 4 to Band 5 crossover setting and/or using a slightly faster
attack time on the Band 5 Leveller/Compressor can help.
Sibilance can sometimes be found in an unlikely place; the L-R. “But voice is mono…”
you say, “…so there is no L-R…” Well, yes and no. When the left and right channels
don’t have perfect balance or there is phase shift between the channels, energy ends up
in the L-R. Why? By denition the L-R signal is the difference between the left and right
channels, regardless of whether it’s level, or phase, or both. When phase is the culprit
the error is generally larger at high frequencies, making the L-R energy also greater at
higher frequencies. As if by magic, sibilance appears in the L-R and the only way to x
it is to tend to what’s causing it or reduce the level of L-R at frequencies where sibilance
might reside. The Leveller’s multiband mixer can help with this. Slightly reducing the
setting of the Band 4 and Band 5 L-R mixer can help tame sibilance without having too
negative an effect on stereo separation.
TREBLE/BRIGHT/OPEN
Treble (like its friends Bass and Midrange) is a generalized term for the high end in
most broadcast and recording systems. Bright and Open are oft-used descriptive terms
of treble styles.
Unfortunately, bright can be a positive or negative term. For instance, laser-bright is
usually a negative term used to describe too much enhancement in the upper end. The
term probably borrows its origins from the early days of CDs when brighter supposedly
meant cleaner.
Open is a term usually reserved for describing audio texture in the upper midrange
when it doesn’t sound overly processed, packed in, or is lacking in detail. To achieve a
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APPENDICES
more open sound in any processor there is usually some sacrice in loudness. Fortunately
the FM-55 is much more forgiving in this regard and most users have an easier time
being loud with the FM-55 while still being quite clean and open. Operating the Leveller
and Compressor with slower attack and release times and making some minor tradeoffs
in loudness will push perceived quality off the charts while going a long way towards
achieving an open and easy to listen to sound. When this is the target sound, starting
with one of our Classical or Jazz presets and then “turning things up” is a good way
to approach achieving this sound. These presets are surprisingly competitive without
sounding “processed.”
FINALLY
As always, Wheatstone’s Tech Support team is available to answer any questions,
help with setup, or assist in tweaking your station to the sound you hear in your head but
might not know how to achieve. Shoot us an email at techsupport@wheatstone.com or
give us a call at 252-638-7000. We know our processors inside and out and can make
them sit up and dance in any market or format.
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APPENDICES
Appendix C
Contents
WheatNet-IP Configuration ..........................................................A-14
Adding FM-55 to The WheatNet-IP System ..............................................................A-14
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APPENDICES
WheatNet-IP Configuration
Along with Digital AES3 and Analog inputs FM‑55 is also equipped with WheatNet‑IP
(WNIP), the Audio Over Internet Protocol (AoIP) used in our Wheatstone BLADE and
IP audio network control surface environment. WheatNet‑IP permits FM‑55’s input
audio and its output to be carried over the same standard CAT5 Ethernet cable as that
used for remotely controlling FM‑55.
This procedure assumes that your facility is equipped with at least one Wheatstone
BLADE and the associated Navigator software. The BLADE used may even be the
multiband, eight processor “Aura8ip” processing BLADE whose physical inputs and
outputs (half analog, half digital) may even be used as a substitute for FM‑55’s physical
I/O.
Open up WheatNet‑IP Navigator to gain access to FM‑55’s WheatNet‑IP‑associated
input and output signals.
Once the WheatNet‑IP Navigator software is open and you are logged into the
system we must create a new device for FM‑55. Because FM‑55 is not a “BLADE”
it appears and operates as a “peripheral device” within the WheatNet‑IP system. Our
Sideboard, an outboard mixer/controller for use with any BLADE’s pair of 8‑channel
utility mixers is one example of a peripheral device. Another example of a peripheral
device is Tieline’s Genie codec. These devices, while technically not BLADEs, can
interact with any WheatNet‑IP system and have signals routed to and from them. What
they lack, however, is the built‑in intelligence of an actual BLADE.
Adding FM-55 to The WheatNet-IP System
The rst thing to do is click on Navigator’s System Peripheral Devices tab (in previous
Navigator GUI versions this was the System 3rd Party Devices tab) which will open a
new window listing any peripheral devices currently present.
Clicking on the Add button opens a dialog where a new FM‑55 may be added to
the system. Here we will add the new FM‑55’s name, its hardware IP address, and tell
the system what BLADE will be its host. At this time we do not have to modify the
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“FM55 Input” and “FM55 Out”.
Of course these signals may be
manually crosspointed (and locked
if desired!) to make connections, or
it may be done through the many
other methods available within the
WheatNet‑IP system for routing
signals and changing the routes of
both audio and logic signals.
More information on conguring
and using WheatNet‑IP Navigator
and the other features and capabilities
of the WheatNet‑IP system may be
found in the WheatNet‑IP BLADE3
Audio Over IP Network manual.
APPENDICES
TCP Port setting so we can leave it set to 60021.
Once input to the dialog is nished, click on the
Ok button and it will close.
Next we’ll open the System Crosspoint window
and see that our new FM‑55’s input and output
signals are now present and available for routing.
Note that as shown in the example below
we’ve used Navigator’s signal name editing
capability to assign FM‑55’s input and output
signals the names we desire. Until changed the
default names begin with “FM55” and will be
Assistance in conguring FM‑55 for WheatNet‑IP may be obtained by giving us a
call at 252‑638‑7000 or by emailing techsupport@wheatstone.com.
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