dbx 160SL User Manual
160SL
Stereo
Compressor/Limiter
Owner’s Manual
IMPORTANT SAFETY INFORMATION
The symbols shown above are internationally accepted symbols that warn of
potential hazards with electrical products. The lightning flash with arrowpoint in
an equilateral triangle means that there are dangerous voltages present within
the unit. The exclamation point in an equilateral triangle indicates that it is
necessary for the user to refer to the owner’s manual.
These symbols warn that there are no user serviceable parts inside the unit.
Do not open the unit. Do not attempt to service the unit yourself. Refer all
servicing to qualified personnel. Opening the chassis for any reason will void
the manufacturer’s warranty. Do not get the unit wet. If liquid is spilled on the
unit, shut it off immediately and take it to a dealer for service. Disconnect the
unit during storms to prevent damage.
Safety InStructIonS
NOTICE FOR CUSTOMERS IF YOUR UNIT IS EQUIPPED WITH A POWER CORD.
WARNING: THIS APPLIANCE SHALL BE CONNECTED TO A MAINS SOCKET OUTLET WITH A
PROTECTIVE EARTHING CONNECTION.
WARNING FOR YOUR PROTECTION
READ THE FOLLOWING:
KEEP THESE INSTRUCTIONS
HEED ALL WARNINGS
FOLLOW ALL INSTRUCTIONS
THE APPARATUS SHALL NOT BE EXPOSED TO DRIPPING OR SPLASHING
LIQUID AND NO OBJECT FILLED WITHI LIQUID, SUCH AS VASES, SHALL
BE PLACED ON THE APPARATUS.
CLEAN ONLY WITH A DRY CLOTH.
DO NOT BLOCK ANY OF THE VENTILATION OPENINGS. INSTALL IN ACCORDANCE WITH THE MANUFACTURER’S INSTRUCTIONS.
DO NOT INSTALL NEAR ANY HEAT SOURCES SUCH AS RADIATORS,
HEAT REGISTERS, STOVES, OR OTHER APPARATUS (INCLUDING AMPLIFIERS) THAT PRODUCE HEAT.
ONLY USE ATTACHMENTS/ACCESSORIES SPECIFIED BY THE MANUFACTURER.
UNPLUG THIS APPARATUS DURING LIGHTNING STORMS OR WHEN
UNUSED FOR LONG PERIODS OF TIME.
Do not defeat the safety purpose of the polarized or grounding-type plug. A
polarized plug has two blades with one wider than the other. A grounding
type plug has two blades and a third grounding prong. The wide blade or third
prong are provided for your safety. If the provided plug does not fit your outlet, consult an electrician for replacement of the obsolete outlet.
Protect the power cord from being walked on or pinched particularly at plugs,
convenience receptacles, and the point where they exit from the apparatus.
Use only with the cart stand, tripod bracket, or table specified by the manufacture, or sold with the apparatus. When a cart is used, use caution when moving
the cart/apparatus combination to avoid injury from tip-over.
The cores in the mains lead are coloured in accordance with the following code:
GREEN and YELLOW - Earth BLUE - Neutral BROWN - Live
As colours of the cores in the mains lead of this appliance may not correspond with the coloured
markings identifying the terminals in your plug, proceed as follows:
•
The core which is coloured green and yellow must be connected to the terminal in the plug
marked with the letter E, or with the earth symbol, or coloured green, or green and yellow.
•
The core which is coloured blue must be connected to the terminal marked N or coloured black.
•
The core which is coloured brown must be connected to the terminal marked L or coloured red.
This equipment may require the use of a different line cord, attachment plug, or both, depending
on the available power source at installation. If the attachment plug needs to be changed, refer
servicing to qualified service personnel who should refer to the table below. The green/yellow
wire shall be connected directly to the units chassis.
CONDUCTOR
L LIVE BROWN BLACK
N NEUTRAL BLUE WHITE
E EARTH GND
WIRE COLOR
Normal Alt
GREEN/
YEL
GREEN
WARNING: If the ground is defeated, certain fault conditions in the unit or in the system to
which it is connected can result in full line voltage between chassis and earth ground. Severe
injury or death can then result if the chassis and earth ground are touched simultaneously.
Refer all servicing to qualified service personnel. Servicing is required when
the apparatus has been damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not operate normally, or
has been dropped.
POWER ON/OFF SWITCH: If the equipment has a Power switch, the Power
switch used in this piece of equipment DOES NOT break the connection from
the mains.
MAINS DISCONNECT: The plug shall remain readily operable. For rackmount or installation where plug is not accessible, an all-pole mains switch with
a contact separation of at least 3 mm in each pole shall be incorporated into
the electrical installation of the rack or building.
FOR UNITS EQUIPPED WITH EXTERNALLY ACCESSIBLE FUSE RECEPTACLE: Replace fuse with same type and rating only.
MULTIPLE-INPUT VOLTAGE: This equipment may require the use of a different
line cord, attachment plug, or both, depending on the available power source at
installation. Connect this equipment only to the power source indicated on the
equipment rear panel. To reduce the risk of fire or electric shock, refer servicing to qualified service personnel or equivalent.
If connected to 240V supply, a suitable CSA/UL certified power cord shall be
used for this supply.
IMPORTANT SAFETY INFORMATION
eLectroMaGnetIc
coMPatIBILIty
This unit conforms to the Product Specifications noted on the Declaration
of Conformity. Operation is subject to the following two conditions:
• this device may not cause harmful interference, and
• this device must accept any interference received, including
interference that may cause undesired operation.
Operation of this unit within significant electromagnetic fields should be
avoided.
• use only shielded interconnecting cables.
u.K. MaInS PLuG WarnInG
A molded mains plug that has been cut off from the cord is unsafe.
Discard the mains plug at a suitable disposal facility.
NEVER UNDER ANY CIRCUMSTANCES SHOULD YOU
INSERT A DAMAGED OR CUT MAINS PLUG INTO A 13
AMP POWER SOCKET.
Do not use the mains plug without the fuse cover in place.
Replacement fuse covers can be obtained from your local retailer.
Replacement fuses are 13 amps and MUST be ASTA approved to
BS1362.
DECLARATION OF CONFORMITY
Manufacturer’s Name: dbx Professional Products
Manufacturer’s Address: 8760 S. Sandy Parkway
Sandy, Utah 84070, USA
declares that the product:
Product name: dbx 160SL
Note: Product name may be suffixed by the letters-EU.
Product option: None
conforms to the following Product Specifications:
Safety: IEC 60065 -01+Amd 1
EMC: EN 55022:2006 (N/A; Analog Product)
IEC61000-4-2
IEC61000-4-3
IEC61000-4-4
IEC61000-4-5
IEC61000-4-6
IEC61000-4-8
IEC61000-4-11
Supplementary Information:
The product herewith complies with the
requirements of the:
Low Voltage Directive 2006/95/EC
EMC Directive 2004/108/EC.
RoHS Directive 2002/95/EC
WEEE Directive 2002/96/EC
With regard to Directive 2005/32/EC and EC
Regulation 1275/2008 of 17 December 2008, this
product is designed, produced, and classified as
Professional Audio Equipment and thus is exempt
from this Directive.
Roger Johnsen
Director, Engineering
Signal Processing
8760 S. Sandy Parkway
Sandy, Utah 84070, USA
Date: August 16, 2011
If you want to dispose this product, do not mix it with general household waste. There is a
separate collection system for used electronic products in accordance with legislation that
requires proper treatment, recovery and recycling.
Private household in the 25 member states of the EU, in Switzerland and Norway may return their used
electronic products free of charge to designated collection facilities or to a retailer (if you purchase a similar
new one).
For Countries not mentioned above, please contact your local authorities for a correct method of disposal.
By doing so you will ensure that your disposed product undergoes the necessary treatment, recovery and
recycling and thus prevent potential negative effects on the environment and human health.
European Contact: Your local dbx Sales and Service
Office or
Harman Signal Processing
8760 South Sandy Parkway
Sandy, Utah 84070 USA
Ph: (801) 566-8800
Fax: (801) 568-7583
160S
160S
160S
160S
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Warranty
160SL
lue seriesb
160SL
160SL
160SL
controls controls
160SL
notes notes
160SL
160SL
160SL
Operations
Inspection Inspection
Operating Operating
Operating Operating
Connection
Installation
Technical
Introduction Introduction
to your system
considerations
support and factory service
160SL
Specifications
lue seriesb
contents
Manual
Introduction .....................................................................................................................................................1
160SL
Why you need compression ...............................................................................................1
The difference between compressors and limiters .....................................................2
The compression and limiting effects ..............................................................................3
Limiters and PeakStopPlus
™
.................................................................................................4
Connection To Your System ...............................................................................................................7
Operating Controls
.....................................................................................................................................8
Front Panel Description ........................................................................................................8
Rear Panel Description ..........................................................................................................13
Operating Notes ......................................................................................................................................... 17
OverEasy
Using the Compression Control .........................................................................................16
Using the Stereo Couple Switch ........................................................................................17
®
and Hard Knee ...................................................................................................16
Using the Auto Switch ...........................................................................................................17
Setting the Attack and Release Controls .........................................................................17
Using PeakStop
Specific Applications ..............................................................................................................19
Sidechain Applications ..........................................................................................................20
®
/PeakStopPlus
™
........................................................................................18
Technical Support/Factory Service................................................................................................ 23
Warranty
Block Diagram
Specifications
........................................................................................................................................................... 23
........................................................................................................................................... 24
................................................................................................................................................ 25
160S
notes notes
160S
160S
160S
Operating Operating
Connection
Installation
Technical
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Advanced
Warranty
160SL
Operations
Why You Need A Compressor
A remarkable feature of the human ear is that it can detect an extremely wide range of amplitude changes from the slightest whisper to a deafening clap of thunder. If one tries to record or reproduce this wide spectrum
of sound with the help of amplifiers, cassette recorders, records, or even digital recorders, one is immediately
restricted by the physical limitations of electronic and acoustic sound reproduction technology.
The useable dynamic range of electronic audio equipment is limited as much at low levels as at high levels. The
thermal noise of electrons in the components results in an audible noise floor and thus represents the bottom limit
of the transmission range. In such equipment, this is referred to as “hysteresis”. Referring to any magnetic media,
hysteresis is the amount of electrical impulse it takes for the tape recorder to begin to rearrange the magnetic
particles of the tape (record signal onto the tape). The more energy it takes, the more noise is introduced onto
the tape, making the noise floor more audible. The amount of hysteresis varies depending on the brand of tape
used, and depends on the materials used in the manufacture of the tape.
When magnetic tape was first used to record audio, hysteresis was a real concern, because it made the useable
dynamic range of magnetic tape very narrow. In the early 1960s, it was discovered that if a tape recorder supplied
an extremely high frequency tone to its record head (much higher than the magnetic tape could possibly record),
the tape’s hysteresis was greatly reduced, or, it took less electrical activity to start to rearrange the magnetic
particles of the tape. The result: a much lower noise floor level and a wider dynamic range. This tone is called a
“bias tone” or “bias frequency.” Today tape manufacturers produce tape optimized for specific bias frequencies,
and studio technicians align tape recorders’ heads according to these specifications, in order to take full advantage
of the tape recorders’ electronics, and the magnetic tape’s ability to record sound on its magnetic particles.
The upper limit of useable dynamic range is determined by the levels of the internal operating voltages; if they
are exceeded, audible signal distortion is the result. Although in theory the useable dynamic range sits between
these two limits, it is considerably smaller in practice, since a certain reserve must be maintained to avoid
distortion of the audio signal if sudden noise peaks occur. Technically speaking, we refer to this reserve as
headroom--usually about 10-20dB. A reduction of the operating level would allow for greater headroom, i.e. the
risk of signal distortion due to high level peaks would be reduced. However at the same time, the basic signal to
noise ratio of the program material would be increased significantly. It is therefore useful to keep the operating
level as high as possible without risking signal distortion in order to achieve optimum transmission quality. It
is possible to further improve the transmission quality by constantly monitoring the program material with the
aid of a volume fader, which manually changes the level of the program material. During low passages the gain
is increased, and during loud passages the volume is decreased. Of course it is fairly obvious that this kind of
manual control is rather restrictive; it is difficult to detect signal peaks and almost impossible to level them out.
Manual control is simply not fast enough to be satisfactory.
Introduction
160SL
The need therefore arises for a fast acting automatic gain control system which will constantly monitor the signals
and which will always adjust the gain to maximize the signal-to-noise ratio without incurring signal distortion.
This device is called a compressor or limiter.
1
160S
160S
160S
160S
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Warranty
lue seriesb
160SL
Operations
lue seriesb
Introduction
160SL
Clipping
Dynamic
Range
The Difference Between Compressors and Limiters
By measuring the dynamic range of musical instruments in live recording situations, you will experience
extreme amplitudes which will often lead to overload in subsequent signal processing equipment. Especially in
broadcasting and digital recording, these signal peaks can lead to heavy distortion. To avoid this kind of distortion
or, to avoid loudspeakers being damaged by overload, compressors and limiters are used.
Noise Floor
Operating Level
Audio levels below here are not heard, because of noise
The principle function of these devices is automatic gain control, as mentioned in the previous paragraphs, which
reduces the amplitude of loud passages and therefore restricts the original signal dynamics within a desired range.
This is useful, especially in conjunction with microphone recording techniques, to compensate for level changes
which are caused by inconsistent microphone techniques on the part of the player, or to restrict the natural
dynamic range of voices or instruments to achieve a more even level.
Although compressors and limiters perform similar tasks, one essential point makes them different:
Clipped signal heavily distorted
Headroom
Useable dynamic range
Limiters abruptly limit the signal above a certain level, while compressors control the signal “gently” over a wide
range. A limiter continuously monitors the signal and intervenes as soon as an adjustable level is exceeded. This
level is called the “threshold”. Any signal exceeding this threshold level will be immediately held below the set
threshold level.
A compressor also monitors the program material continuously and also has a set threshold level. However,
in contrast to the limiter, signals exceeding the threshold are not reduced abruptly, but gradually. Above the
threshold the signal is reduced in level relative to the amount the signal exceeds this point.
Generally, threshold levels for compressors are set below the normal operating level to allow for the upper
dynamics to be musically compressed. For limiters, the threshold point is set above the normal operating level in
order to provide peak signal limiting and thus protects subsequent equipment.
2
160S
notes notes
160S
160S
160S
Operating Operating
Connection
Installation
Technical
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Advanced
Warranty
Headroom
Useable dynamic range
Operating Level
Headroom
Clipping
Noise Floor
Useable dynamic range
Clipped signal heavily distorted
Audio levels below here are not heard, because of noise
Headroom
Useable dynamic range
Clipped signal heavily distorted
Audio levels below here are not heard, because of noise
+10
input
dBu
Operating Level
Headroom
Clipping
Noise Floor
Useable dynamic range
Clipped signal heavily distorted
Audio levels below here are not heard, because of noise
+10
0
-10
-20
time
+10
0
-10
-20
time
input
dBu
Figure 2 Figure 1
input
dBu
output
output
Headroom
Useable dynamic range
Clipped signal heavily distorted
Audio levels below here are not heard, because of noise
+10
input
dBu
160SL
Operations
The Compression and Limiting Effects
On a compressor, there is a relationship between the input signal, and the threshold level, input, output, and
ratio settings. Look at an input signal applied to the inputs of two compressors. The threshold level of the second
unit is set ten decibels higher than the threshold of the first unit. Since a compressor only affects signals that
exceed the threshold level, it is obvious that the signal of the first compressor will be compressed more, because
it exceeds the threshold level more than the level of the second unit, because the second compressor’s threshold
level is set higher.
input
dBu
+10
0
-10
-20
input
dBu
+10
0
-10
-20
Introduction
160SL
input
dBu
+10
0
Input of compressors
at different threshold
settings.
-10
= threshold
-20
time
The difference between compression and limiting is shown visually below. In the first diagram below, compression
“squashes” the signal. Its peaks are lowered, but the overall level of the signal is raised due to applied makeup gain (Output Gain). In the second diagram, the peaks are lowered to the threshold level, but the rest of the
signal has not been altered.
dBu
+10
0
-10
-20
Obviously, there is a large difference between these two signals in relation to their dynamic range and the
processed signal. In the third figure, it is shown to have been compressed, and in the fourth figure, it has been
limited.
time
Figure 1
time
dBu
+10
-10
-20
0
Figure 3 Figure 4
time
Figure 2 Figure 1
Difference in output of
compressors and limiters.
time
= threshold
3
160S
160S
160S
160S
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Warranty
lue seriesb
160SL
Operations
lue seriesb
Introduction
Furthermore, it is interesting to note that by comparing the input and output waveforms for the compressed
mode, the quietest sections of the input signal have been effectively raised in level, whereas the loudest sections
have been effectively decreased in level. The overall effect is that both ends of the dynamic range have been
pushed toward the middle. This squashing effect of compression is important to remember and highlights the
major difference between compressing and limiting.
Compressing and limiting differ in one more aspect: the dynamic settings for attack and release times. Attack
time is defined as the time taken to for a compressor to respond to program levels which have exceeded the
threshold point. Release time is the amount of time a compressor takes to return the program level to its original
level, after the last excursion over the threshold point. For compression, a preferably longer attack and release
time are generally the best in order to keep the overall output signal within a specified dynamic range. For
limiting applications, considerably shorter attack and release times are necessary to control fast transient signals
or to increase headroom.
To achieve inaudible compression, it is advisable to work with program dependent attack and release times. The
advantage of program dependent compression is most apparent when processing musical material that is varied.
The dbx 160SL Stereo Compressor is suitable for all applications because of its ability to be manually set at both
attack and release parameters.
160SL
Limiters and PeakStopPlus
Lower frequencies work best when compressed with slower attack times. When compressing a mix that includes
a wide range of frequencies, a compromise is made when setting the attack time. The attack setting would
generally suit the lowest frequency components of the material. For general dynamic range control with a
compressor, this is of no serious consequence.
However, in a “limiting” situation, where we are restricting the peaks of our signal to a maximum operating level
to avoid distortion in subsequent devices, a slow attack time is not acceptable. This would result in very fast
high frequency signal transients passing through unaffected by gain reduction. These transients could then cause
distortion in the following equipment such as tape recorders and radio transmitters. It is therefore necessary to
choose an attack time which is as close to “zero” attack as possible, independent of the frequency.
This makes the limiter necessary, and it’s why we include a peak limiter on almost all of our compression
products. The dynamics of the dbx limiters are set to handle these fast transients through a process called
PeakStop® and the newer, improved two-stage process called PeakStopPlus
The first stage of PeakStopPlus is the Instantaneous Transient Clamp™ which clamps the signal with a soft logarithmic clamp
function. This logarithmic function assures that the signal will not exceed the level set by the PeakStopPlus™ LEVEL control
by more than 2 dB typically, and that it will not introduce harsh artifacts. The second stage is a unique program limiter
featuring Intelligent Predictive Limiting™. Its function is to monitor the input signal and intelligently predict the amount of
gain reduction needed to keep the output signal below the ceiling set by the Instantaneous Transient Clamp™. Note, since
the PeakStopPlus™ limiter is a fail-safe limiter it must come after the OUTPUT GAIN control. If the output gain is set too high
as compared to the PeakStopPlus™ Level control, continuous limiting can occur. While PeakStopPlus™ is typically used as
a protective function, creative effects can be achieved by intentionally driving the signal into heavy PeakStopPlus™ limiting.
Great care has gone into the design of the PeakStopPlus™ limiter to keep it acoustically transparent. Appropriate use of it
can protect your gear while keeping the signal free of artifacts.
™
®
.
4
160S
notes notes
160S
160S
160S
Operating Operating
Connection
Installation
Technical
to your system
considerations
contents
concept
diagram
applications
support and factory service
160S
160S
160S
160S
160S
160S
160S
Manual
Design
Block
Controls
Advanced
Warranty
160SL
Operations
For best results the Limiter functions of your compressor should be used in conjunction with the Compressor
functions.
When we at dbx decided to make a premium compressor that would perform to the industry’s highest standards,
it became readily obvious that every component and design strategy had to be chosen with high-performance
foremost in mind. After the evolutionary process of engineering design and implementation was complete, the
result was stunning. Here is a partial list of the features found on the 160SL. You won’t hear about most of them
anywhere else, but they are critical to the amazing specs, comprehensive functionality, and visionary design of
the 160SL Stereo Compressor.
• New dbx V8™ VCA module exhibits a dynamic range of 127dB
with extremely low distortion!
• V8™ VCA is encased in a specially-designed zinc-aluminum
housing for shielding and thermal characteristics. This allows for
peak performance of the VCA in any environment.
• Precision 0.1% and 1% metal film resistors.
• Gold-palladium- nickel board-to-board connectors.
• Jensen® transformers.
• Gold-plated Neutrik® XLR connectors.
• Rare earth magnet relays with gold contacts in a hermetically
sealed nitrogen environment.
• Military-grade glass epoxy circuit boards.
• Double-shielded Toroid transformer ensures no self-generated
power supply noise enters the audio path.
• High-drive output transformers are capable of driving 1000 feet of
Belden 8451 cable to +30dBm.
• Striking blue custom-machined, 1/4” thick front panel.
• Hand-crafted, solid aluminum knobs.
• LEDs mounted in machined, stainless steel housings.
• Custom dbx VU meters with peak indicators.
• Heavy-gauge chassis.
• Switchable OverEasy®/hard knee characteristics enable the 160SL
to sound like the traditional 165A as well as the old and still
popular 160.
• Program dependent Auto mode, or fully variable attack and
release.
• PeakStop/PeakStopPlus™ switchable limiting topologies, the
perfect complement to the 160SL feature set.
• Sidechain capabilities, switchable from the front panel.
Introduction
160SL
5
Loading...