Lab.gruppen PLM 12K44 Operation Manual
PLM+ SERIES
Powered Loudspeaker Management™ System
Operation Manual
PLM 20K44
PLM 12K44
Incorporating technologies from
1. Important safety instructions
2
PLM+ SERIES Operation Manual rev 1.0.0
1. Important safety instructions
Before using the device, be sure to carefully read the Safety Instructions. Keep this document with the device at
all times.
1. Read these instructions.
2. Keep these instructions
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation openings. Install in accordance
with the manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat
registers, stoves, or other apparatus (including ampliers)
that produce heat.
9. 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
the third prong is provided for your safety. If the provided
plug does not t into your outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles, and the point
where they exit from the apparatus.
11. Only use attachments/accessories specied by the
manufacturer.
12. Use only with a cart, stand, tripod, bracket, or table specied
by the manufacturer, or sold with the apparatus. When a
cart is used, use caution when moving the cart/apparatus
combination to avoid injury from tip-over.
13. Unplug this apparatus during lightning storms or when
unused for long periods of time.
14. Refer all servicing to qualied 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.
15. Use the mains plug to disconnect the appartus from the
mains.
16. WARNING: To reduce the risk of re or electric shock, do not
expose this apparatus to rain or moisture.
17. Do not expose this equipment to dripping or splashing and
ensure that no objects lled with liquids, such as vases, are
placed on the equipment.
18. The mains plug of the power supply cord shall remain readily
operable.
19. Do not connect the unit’s output to any other voltage source
such as battery, mains source, or power supply, regardless
of whether the unit is turned on or off.
20. Do not remove the top (or bottom) cover. Removal of the
cover will expose hazardous voltages. There are no user
serviceable parts inside and removal may void the warranty.
21. An experienced user shall always supervise this professional
audio equipment, especially if inexperienced adults or
minors are using the equipment.
22. The US National Differences clause 16.3 requires that
network cables must be ame rated VW-1.
1.1. Approvals
1.2. Warnings
1.2.1. Explanation of warning symbols
1.2.2. Warnings
To prevent electric shock do not remove top or bottom
covers. No user serviceable parts inside, refer servicing to
qualied service personnel.
Français: À prévenir le choc électrique n’enlevez pas les
couvercles. Il n’y a pas des parties serviceable à l’intérieur, tous
reparations doit etre faire par personnel qualié seulment.
The lightning bolt triangle is used to
alert the user to the presence of
un-insulated “dangerous voltages”
within the unit’s chassis that may be
of sufcient magnitude to constitute a
risk of electric shock to humans.
The exclamation point triangle is used to
alert the user to presence of important
operating and service instructions in the
literature accompanying the product.
This equipment conforms to the requirements
of the EMC Directive 2004/108/EC and the
requirements of the Low Voltage Directive
2006/95/EC.
Standards applied: EMC Emission
EN55103-1, E3
EMC Immunity EN55103-2, E3, with S/N
below 1% at normal operation level.
Electrical Safety EN60065, Class I
This equipment is tested and listed according to the
U.S. safety standard ANSI/ UL 60065 and
Canadian safety standard CSA C22.2
NO. 60065. Intertek made the tests and they
are a Nationally Recognized Testing Laboratory
(NRTL).
1. Important safety instructions
PLM+ SERIES Operation Manual rev 1.0.0
3
To completely disconnect this equipment from the AC
mains, disconnect the power supply cord plug from the AC
receptacle. The mains plug of the power supply cord shall
remain readily operable.
Français: Pour démonter complètement l’équipement de
l’alimentation générale, démonter le câble d’alimentation
de son réceptacle. La prise d’alimentation restera aisément
fonctionnelle.
To reduce risk of re or electric shock, do not expose this
apparatus to rain or moisture.
Français: Pour réduire les risques d’incendie ou de choc
électrique, n’exposez pas l’appareil à la pluie ou à l’humidité.
Do not expose this system/apparatus to dripping or splashing
and ensure that no objects lled with liquids, such as vases,
are placed on the apparatus.
Français: N’exposez pas ce système/appareil au
ruissellement ni aux éclaboussures et assurez-vous qu’aucun
objet contenant du liquide tel qu’un vase n’est placé sur
l’appareil.
This apparatus must be connected to a mains socket outlet
with a protective earthing connection.
Français: Cet appareil doit être raccordé à une prise secteur
avec terre de protection.
The mains plug is used as a disconnect device and shall
remain readily operable.
Français: Lorsque la prise du réseau d’alimentation est utilisés
comme dispositif de déconnexion, ce dispositif doit
demeuré aisément accessible.
1.2.3. Caution
To reduce the risk of re or electric shock, do not remove screws.
No user-serviceable parts inside. Refer servicing to qualied
service personnel.
Français: Pour réduire le risque d’incendie ou de choc
électrique, ne pas retirer les vis. Aucune pièce réparable par
l’utilisateur. Coner l’entretien àpersonnel qualié.
1.2.4. User responsibility
Mains connection grounding
Your amplier must be connected to a grounded socket outlet.
Speaker output hazard on amplifiers
Ampliers are capable of producing hazardous output
voltages. To avoid electrical shock, do not touch any exposed
speaker wiring while the amplier is operating. The external
wiring connected to the speaker terminals shall be installed
by a qualied person, or ready-made leads or cords of
appropriate capacity shall be used.
As the power output channels on ampliers produce high
voltage, do not connect or disconnect speaker cables when
the mains power is on.
Radio interference
A sample of this product has been tested and complies with
the limits for the European Electro Magnetic Compatibility
(EMC) directive. This equipment has also 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 from electrical equipment. This product uses
radio frequency energy and if not used or installed in
accordance with these operating instructions, may cause
interference to other equipment, such as radio receivers.
However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which
can be determined by turning the equipment on and off, the
user is encouraged to try to correct the interference by one or
more of the following measures:
• Reorient or relocate the antenna.
• Increase the separation between the equipment and
re c e iver.
• Connect the equipment to an outlet on a circuit different
from that to which the receiver is connected.
• Check if the affected unit complies with the EMC limits for
immunity, (CE-labeled). If not, address the problem with
the manufacturer or supplier. All electrical products sold
in the EC must be approved for immunity against
electromagnetic elds, high voltage ashes, and radio
interference.
• Consult the dealer or an experienced radio/TV technician
for help.
Speaker damage
Amplier apparatus is very powerful and can be potentially
dangerous to both loudspeakers and humans alike. Many
loudspeakers can be easily damaged or destroyed by
overpowering them. Always check the speaker’s continuous
and peak power capabilities. Although the ampliers
attenuators can be used to reduce the overall gain, an
increase of the input signal can result in full output power,
which may cause damage to connected speakers.
Maintenance
For safe and reliable operation, the dust lters on both sides
of the front panel, behind the grilles, should be removed and
cleaned regularly to ensure maximum airow through the
device.
If the dust lters are not maintained there will be safety
risks; for example, high internal temperatures could ignite
the dust and start a re. There is also a risk that the unit will
malfunction since it is dependent on constant airow from
front to rear. If the dust lters are not clean and the unit
malfunctions, any resulting problems will not be covered by
the warranty.
This Class A digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe A est conforme à la norme NMB-003
du Canada.
Table of Contents
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PLM+ SERIES Operation Manual rev 1.0.0
Table of Contents
1. Important safety instructions 2
1.1. Approvals
2
1.2. Warnings
2
2. Introduction 6
2.1. Welcome
6
2.2. Main Features
6
2.3. Additional Documentation
8
3. Installation 8
3.1. Unpacking
8
3.2. Mounting
8
3.3. Cooling
10
3.4. Operating Voltage
10
3.5. Grounding
11
4. Product Overview 12
4.1. Front Panel Overview
12
4.2. Rear panel
14
5. Operation and performance 16
5.1. Operation precautions
16
5.2. Power Output Performance
16
5.3. Amplier and Load Protection Systems
18
5.4. Power Supply
24
6. Signal Flow and Lake® Processing 25
6.1. Signal Flow
25
6.2. Level Adjustments & Mute Points
25
6.3. Lake Processing and Control
26
6.4. Modules and Frames
27
6.5. Loudspeaker Processor Overview
27
6.6. Files and Presets
28
7. Front Panel Interface 29
7.1. Overview
29
7.2. Front Panel Key Lock
30
7.3. Power Button
30
7.4. Mute Enable Button
31
Table of Contents
PLM+ SERIES Operation Manual rev 1.0.0
5
7.5. Meter Button 31
7.6. Menu Button
31
7.7. Exit Button
31
7.8. Dynamic Buttons, Controls and LEDs
32
7.9. Warning and Fault Indications
37
7.10. Meter Mode
39
7.11. Menu Mode
43
8. Back Panel Interface 57
8.1. Speaker Outputs
57
8.2. Analog Inputs
60
8.3. AES3 Digital I/O
62
8.4. RJ45 etherCON Network Connections
62
8.5. Power Inlet
64
9. Appendix 65
9.1. Faults and Warnings Overview
65
9.2. Maintenance
68
9.3. Factory Default Settings
68
9.4. Current Draw and Thermal Dissipation Specications
70
9.5. Glossary of Terms, Acronyms and Abbreviations
72
10. Application Guide 74
10.1. Rack I/O Panels
74
10.2. Power Distribution
74
10.3. Gain Structure
75
10.4. Gain / Level Optimization
77
10.5. Speaker Congurations
80
10.6. Digital Audio Connections
80
10.7. Digital Clock Conguration
83
11. Technical Specications 85
12. Warranty and Support 87
12.1. General
87
12.2. International Warranties
87
12.3. Technical Assistance and Service
87
2. Introduction
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PLM+ SERIES Operation Manual rev 1.0.0
2. Introduction
2.1. Welcome
Thank you for choosing the Lab.gruppen PLM+ Series of Powered Loudspeaker Management systems for your
sound reinforcement needs. We are condent that you will be pleased with the performance, unique features,
conguration exibility, reliability, and long-term durability offered by this product.
For fast installation and use of this product, your welcome package includes a printed copy of the PLM+ Series
Quick Start Guide which contains the information required to safely install the product and place it in service.
Control and editing features are accessible via the front panel interface or via the included Lake Controller software.
It is recommended that the Quick Start Guide and all product documentation on the included USB key is reviewed
to ensure familiarity with the various conguration and control options.
Thank you again for placing your condence in Lab.gruppen products.
2.2. Main Features
The PLM+ Series incorporates a number of sophisticated technologies to ensure the best possible performance
and many years of reliable operation. The following section summarizes the benets of each feature; additional
information is available in the reference manuals.
2.2.1. Amplifier Platform
The PLM+ Series power output section has expanded upon Lab.gruppen’s robust, road-proven
PLM 20000Q amplier. Features common to both platforms include extraordinary power density; 4 channels of
patented Class TD® output stages, a Power Factor Corrected (PFC), Regulated Switch Mode Power Supply
(R.SMPS™), the high-efciency Intercooler® copper-nned cooling system, and a full suite of protection features,
including the Breaker Emulation Limiter (BEL). Signal inputs are analog, AES digital, and Dante digital audio
network.
2.2.2. Amplifier DSP (Digital Signal Processor)
Various features of PLM+ Series devices are controlled by the on-board DSP, some of which are summarized in
this section.
2.2.2.1. Input Gain (Sensitivity)
Input gain (sensitivity) is set in the digital domain for PLM+ Series devices, and may be controlled via the Lake
Controller software or front-panel interface.
2. Introduction
PLM+ SERIES Operation Manual rev 1.0.0
7
2.2.2.2. ISVPL™
The Inter-Sample Voltage Peak Limiter (ISVPL) tailors each power output to the characteristics of the connected
load. Please refer to section 5.3.1 for further information.
2.2.2.3. Load Verification & Performance Monitoring
A comprehensive set of proprietary DSP-based tools are provided for load verication and real-time performance
monitoring. These functions utilize LoadLibrary, a comprehensive database for each loudspeaker component of the
connected load (usually one or more band-limited drivers in a multi-way system).
Using this data and a brief test signal, LoadSmart compares actual response to predicted response, identifying
any malfunctioning components or connection errors. During the performance, PLM+ monitors real-time voltage,
current draw, and temperatures of the PLM+ amplier stages as well as the power supply. This allows operators to
avoid power compression and identify potential problems.
Please refer to the Lake Controller Operation Manual for detailed information on PLM+ Series load verication
and real-time performance monitoring functionality.
2.2.3. Lake Processing and Controller
PLM+ Series devices integrate seamlessly into the Lake Processing environment and are accessible via the Lake
Controller software. Processing modules offer precise settings for gain, delay, crossover settings, equalization and
limiting. Lake processing features incorporated in each module include Raised Cosine Equalization™, linear phase
crossovers, and LimiterMax™ loudspeaker protection. Please refer to the Lake Controller Operation Manual for
further information.
2.2.4. Analyzer Plug-in
Lake Controller software provides integration with third-party real-time analyzers, providing simultaneous
measurement display and EQ adjustment via the Lake Controller. Approved analyzers include Rational Acoustics
Smaart 7, SysTune from AMFG, and WaveCapture Live-Capture Light or Live-Capture Pro; additional third-party
analyzers may be approved in the future.
Please refer to the Lake Controller Operation Manual for further information regarding the Analyzer plug-in and
associated functionality.
2.2.5. Dante™ Audio Network
PLM+ Series devices include Dante digital audio networking as standard. Utilizing the latest advances in Ethernet
technology, Dante offers simplied system conguration and extremely low latency while delivering very high quality
uncompressed digital audio across the Lake network. The Zen™ automatic conguration feature enables plugand-play setup without third-party DHCP or DNS servers. Dante is compatible with high-bandwidth networks,
allowing large numbers of audio channels to be distributed alongside control and analyzer data.
3. Installation
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PLM+ SERIES Operation Manual rev 1.0.0
2.3. Additional Documentation
This document, the PLM+ Operation Manual, serves as the primary reference source for detailed information
on the installation and operation of PLM+ Series Powered Loudspeaker Management systems. It also provides
detailed information on set-up and conguration using the front-panel interface.
If you intend to use the device as part of a networked system, or access features via the Lake Controller, please
refer to the various supporting documents which can be located via these methods:
• Start > Programs > Lake Controller > Documentation (after installing Lake Controller software)
• On the included installer USB key, or via the downloaded software installer
• Online at: http://labgruppen.com/products/documentation/
3. Installation
3.1. Unpacking
Carefully open the shipping carton and check for any damage to the device or the supplied accessories. Every
Lab.gruppen product is tested and inspected before leaving the factory and should arrive in perfect condition. If
any damage is discovered, please notify the shipping company immediately. Only the consignee may initiate a
claim with the carrier or their insurers for damage incurred during shipping. Save the carton and packing materials
for the carrier’s inspection.
In addition to the PLM+ Series device, the shipping carton includes the following items:
• PLM+ Series Quick Start & Field Reference Guide
• AC mains lead (power cable) with Neutrik® powerCON® connector
• Rear brackets for additional rack support (pair) along with associated mounting hardware
• Software Installer and Documentation USB key
Please keep the original carton and associated packaging to facilitate shipping of the device should the need arise.
3.2. Mounting
Airow for cooling the device is from front panel (intake) to rear panel (exit). Please ensure that no objects, such as
rack doors or lids, are placed at the front or rear of the rack to ensure that airow is maximized. This device has no
top or bottom vents and therefore PLM+ units may be stacked directly on top of each other.
Sufcient space should be available at the front of the rack to accommodate the handles, and at the rear to
accommodate connectors and cables; allowance must be made for cable or loom bends within a rack.
3. Installation
PLM+ SERIES Operation Manual rev 1.0.0
9
3.2.1. Rear Mounting
Two rear support brackets along with associated mounting hardware are included with the PLM+, as shown in
Figure 3.1; it is recommended that these are used wherever possible. Fit the brackets to the vertical rails at the rear
of the rack. Figure 3.2 and Figure 3.3 show the tting options for xed and removable installation.
The support brackets are reversible and may be tted to point either to the front or rear of the rack; the orientation
used depends on the rack depth and position of the rear rack rails.
Two mounting methods are possible; note that the method shown in Figure 3.2 additionally provides extra security
against unauthorized removal. For situations where rapid removal and replacement is required, the method shown
in Figure 3.3 should be used.
Fig 3.1: Rear support bracket with mounting hardware
Fig 3.2: Rear support bracket mounted for Fig 3.3: Rear support bracket mounted for
xed installation and bracket pointing forward removable installation and bracket pointing back
3. Installation
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PLM+ SERIES Operation Manual rev 1.0.0
3.3. Cooling
3.3.1. Overview
The PLM+ Series devices use a forced-air cooling system with airow from front to rear, allowing high continuous
power levels without thermal problems. Front-to-rear airow is preferable as air at the front of a rack is cooler than
that at the rear in nearly all situations; never attempt to reverse the airow. The operation of the PLM+’s cooling
system is dependent on front-to-rear airow; it will not function effectively with external airow in the opposite
direction.
Make sure an adequate air supply is provided in front of the PLM+, and that the rear of the PLM+ has sufcient
space to allow air to escape. If the PLM+ is rack-mounted, never operate the unit with any front or rear rack doors
or covers in position. It is recommended to keep the ambient temperature around the PLM+ as cool as possible.
An increased temperature can have a signicant negative impact on the expected lifetime on the components
inside the PLM+.
Note: Fit solid blanks (not ventilation blanks) to unused rack spaces to ensure effective air circulation.
Leaving gaps in between items of equipment degrades the effectiveness of forced-air cooling.
If installing one or more PLM+ Series devices in a rack with other fan-cooled equipment, be sure that all the
other equipment also uses front-to-rear airow for cooling. If this precaution is not observed, there is a risk of
overheating, as units with the reverse airow will be drawing in air which has already been heated by the PLM+s.
3.3.2. Temperature Sensing and Protection
The PLM+ is equipped with a sophisticated temperature sensing system which protects it from any overheating
which may occur as a result of inadequate ventilation.
Note: Always ensure the dust lters behind the detachable front panel are clean to ensure maximum
possible airow.
3.4. Operating Voltage
The label adjacent to the mains (AC) input connector indicates the AC mains voltage for which the device is wired
and approved. Both PLM+ models incorporate a universal power supply operating from 80 to 265 V. Only connect
the mains cable (AC cord) to an AC source of the voltage shown on the label.
The PLM+ uses primary switching, which means the mains power is rectied on the primary side of the
transformer. This makes the power supply insensitive to mains frequency variation, and it will operate normally on
line frequencies from 45 to 75 Hz.
3. Installation
PLM+ SERIES Operation Manual rev 1.0.0
11
If the mains plug (AC plug) tted to the mains cable (AC cord) is not appropriate for your country, it can be removed
and a locally-sourced one tted instead, observing the color coding in the table below:
Table 3.1: AC Plug Conguration
If you are not 100% condent of your competence to replace the mains plug (AC plug), the task should be carried
out by qualied personnel.
Once a suitable AC power supply is connected, the device can be turned on using the front panel power button.
When the device is turned on, the power button LED changes from red (Standby) to green (Active).
Note: In-rush current is controlled and limited during the soft-start sequence. This enables multiple
PLM+ units on the same AC mains circuit to be turned on simultaneously
3.5. Grounding
Analog inputs feature Iso-Float™ ground isolation, a technology which combines the benets of transformer
coupled isolation with the advantages of clean, direct-coupled inputs.
The audio converters are galvanically isolated, and not connected to mains ground. High-speed transformers and
opto-isolators create a barrier between the device and the outside electrical environment.
Note: The Iso-Float feature is activated by default, but may be disabled via the Lake Controller software,
or via the front panel menu.
Use correctly-shielded balanced audio input connections to minimise hum and interference. Please refer to section
8.2.4 for further information.
NEVER disconnect the earth (ground) pin on the mains cable (AC power cord).
powerCON pin
L Brown
N Blue
Green/Yellow
4. Product Overview
12
PLM+ SERIES Operation Manual rev 1.0.0
4. Product Overview
4.1. Front Panel Overview
The front panel presents the following amplier status indicators:
The front panel controls are clustered around a daylight readable LCD 3 , allowing adjustment and monitoring of
the majority parameters and meters. The two clusters of controls on either side of the LCD include ve dedicated
function buttons
4 5 6 7
12
, eight dynamic function buttons with embedded LEDs
8 9
and a rotary data
encoder 11 .
1
Handles – Two sturdy cast aluminium handles are integrated into the front panel. The handles should be used
when carrying the device, and when tting into or removing from a rack. Ensure that any door or removable rack
front cover has sufcient depth to clear the handles.
2
Dust Filters – Two dust lters are tted behind metal covers. To remove the covers, loosen the thumbscrews
located behind the handles. Once detached, the dust lter elements can be removed for cleaning; please refer to
section 9.2 for further information.
Note: NEVER operate this device without the dust lters in place.
3
Display – The display illuminates when the device is on. The LCD, function buttons, and the rotary encoder
provide real-time control and monitoring of most parameters. The LEDs embedded in the function buttons indicate
available menu options, provide conrmation of Controller communication, and indicate various faults and
warnings.
The brightness and contrast of the display and front panel LEDs can be adjusted via the front panel menu. A
screensaver will turn off the display when the unit is left without any action or signal present. It will light up again
at the push of any button or when signal reaches above 20 dB on any input. Please refer to section 7 for further
details.
4
Standby – PLM+ Series devices are powered on and to standby using the top-left button, or via the
Lake Controller.
3
1 2 4
5
6
7 8 9 12
11
10 2 1
4. Product Overview
PLM+ SERIES Operation Manual rev 1.0.0
13
5
Mute Enable – Select MUTE ENABLE to allow the dynamic function buttons to operate as mute controls for
the Module inputs and power output channels. The MUTE ENABLE button ashes when the mode is selected;
a subsequent press deselects this mode. If left activated, MUTE ENABLE mode will automatically disable two
minutes after the last mute action.
6
Meter – The METER button scrolls through various meter views including the default Home View, Amplier
Meters View, Temperature Meters View, Input Meters View and Module Meters View. Pressing METER from Menu
Mode returns the screen to Meter Mode with the Home View displayed. Please refer to section 7.5 for further
details.
7
Menu – After pressing the MENU button, the LCD will display the top level menu. In Menu Mode the dynamic
function buttons enable access to various information and functionality. Please refer to section 7.6 for further details.
8
Dynamic Function Buttons with LEDs (Left of LCD) – The function of these buttons change according to
the currently selected view or menu.
• In Menu Mode they are used for menu navigation and for parameter selection
• In Meter Mode they provide Module input mute/unmute functionality in conjunction MUTE ENABLE
The left buttons provide Module input mute functionality, mute indication and faults and warning indications relating
to the individual PLM+ inputs. All four LEDs will iluminate simultaneously when indicating global faults or warnings.
Please refer to section 7 for further details.
9
Dynamic Function Buttons with LEDs (Right of LCD) – The function of these buttons change according to
the currently selected view or menu.
• In Menu Mode they are used for menu navigation and for parameter selection
• In Meter Mode they provide PLM+ output mute/unmute functionality in conjunction MUTE ENABLE
All LEDs provide individual mute, clip, fault and warning indications for the PLM+ power outputs channels. Please
refer to section 7 for further details.
10
Communication LED – The high-intensity white LED illuminates white to indicate that the Module/Frame is
selected in the Lake Controller; it ashes white to indicate communication with the Lake Controller.
The brightness of the LCD and communications LED can be adjusted in the Frame page of the Main Menu on the
front panel.
11
Rotary Encoder – The rotary encoder is used to modify various parameters (e.g. input level) via the menu.
When a menu item is selected that permits adjustment of parameter values, the ring around the rotary encoder
illuminates. In Home View the encoder can be used to scroll through the Meter Views.
12
Exit – The EXIT button is used primarily while navigating the menu system in Menu Mode; pressing EXIT will
return the menu up one level. In Meter Mode, pressing EXIT returns the metering display to the default Home View.
4. Product Overview
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PLM+ SERIES Operation Manual rev 1.0.0
4.2. Rear panel
3 4 51
2
INPUT 1 INPUT 2 INPUT 3
AES/EBU
INPUT 1-2 INPUT 3-4
SECPRIM
Must be grounded/earthed
Made in Sweden
PIN 1: SCRN 2: POS 3: NEG
ANALOG WITH ISO-FLOAT
TM
50-60Hz
100-240V 2400-2950W
Ser. N:o
Removed!
CH 2
CH 1
CH 4
CH 3
SPEAKER OUTPUTS
CLASS 3 WIRING
BRIDGE
BRIDGE
INPUT 4
SWITCHED 00/ 000 Base-TX1 1
1Gbps 1Gbps
LINK
ACT
LINK
ACT
PLM 2K44
1
1+/- CH 1+/2+/- CH 2+/-
1+/- CH 1+/2+/- CH 2+/-
3+/- CH 3+/4+/- CH 4+/-
1+/- CH 3+/2+/- CH 4+/-
CLASS 3
WIRING
BRIDGE CH 1 & 2:
1+:+
2- : -
BRIDGE CH 3 & 4: 1+ : +, 2- : -
SPEAKER OUTPUTS
INPUT 1 INPUT 2 INPUT 3
AES/EBU
INPUT 1-2 INPUT 3-4
SECPRIM
Must be grounded/earthed
Made in Sweden
PIN 1: SCRN 2: POS 3: NEG
ANALOG WITH ISO-FLOAT
TM
50-60Hz
100-240V 2400-2950W
INPUT 4
SWITCHED 00/ 000 Base-TX1 1
1Gbps 1Gbps
LINK
ACT
LINK
ACT
PLM 2K44
1
6
The PLM+ is available with a choice of connectors for power outputs: binding posts or Neutrik speakON®. Both
connection methods allow for Bridge Mode operation, which is activated from the Lake Controller software. Please
refer to the Lake Controller Operation Manual and section 8.1.1 of this Operation Manual for further information on
Bridge Mode.
1
Binding Posts – In this version, the power outputs for loudspeaker connection are available on four separate
pairs of fully enclosed binding posts. Bridge Mode can be enabled via the Lake Controller software; please refer to
the Lake Controller Operation Manual for further information.
2
speakON Connectors – The power outputs are simultaneously available on a single 8-pole speakON
connector, and on two 4-pole speakON connectors. The two 4-pole connectors carry the outputs of channels 1
& 2 and 3 & 4 respectively. Bridge Mode can be enabled via the Lake Controller software. Please refer to the Lake
Controller Operation Manual.
3
Analog Inputs – Analog inputs are available on four standard XLR3F latching connectors. The inputs are
electronically balanced and feature Lake Iso-Float circuitry. The impedance is 20 kohms, and the inputs can accept
a maximum input level of +26 dBu.
4
AES3 Inputs – Two latching XLR3F connectors are provided for AES3 digital audio signals (four audio
channels). Input impedance is 110 ohms, please ensure that 110 ohm digital audio cables are used; standard XLR
microphone cables are rarely suitable for reliable digital audio transmission.
Note: The PLM+ does not provide Analog or AES loop through / Link connectors. Where needed,
it is recomended to use Y-split cables or patchpanels wired to connect the Inputs with Link output
connectors. The AES3 termination load shall be enabled when the PLM+ is the last unit connected
within an AES3 daisy-chained system. The termination may be disabled, if desired, via the front panel
menu and within the Lake Controller software.
4. Product Overview
PLM+ SERIES Operation Manual rev 1.0.0
15
5
Primary Network Connector – The primary Neutrik RJ45 etherCON® connection provides integration into
an Ethernet control network which may include other Lake Processors and the Lake Controller software. Network
connection permits full control of all functions along with real-time metering from a remote position. This device
supports the Dante audio networking protocol, which allows transmission of multichannel, high-denition digital
audio over the same Ethernet connection.
Use the primary connector when using a star network topology, consisting of individual Cat-5e connections
between the devices and an Ethernet switch. Alternatively this connection can be used to daisy chain directly to
another Lake Processor. The daisy chain topology should not be used with Dante. For a technical reference to the
Ethernet Port, please refer to section 8.4. Additional information is also available in the Lake Network Conguration
Guide.
Note: The Ethernet ports operate at the Ethernet data rate of up to 1 Gbps and allow straight or
crossed network cables. LEDs above each port indicate network activity (ACT) and Gigabit network
connections (Gbps). If Gbps LED is unlit, speed is 100 Mbps.
6
Secondary Connector – The secondary network connector can be used to daisy-chain multiple LM,
PLM, PLM+ or D Series devices. Alternatively, a Dante dual-network topology can be created by connecting all
secondary network connectors to a separate Ethernet switch, ensuring full redundancy in the event of a network
component failure.
Note: Additional processor conguration is required for a dual redundant network setup. The device
may be congured for Dual Redundancy from the Network menu of the front panel or via Lake
Controller. See the Lake Controller Operation Manual for further details.
When the device operates in Dual Redundancy, a symbol (=) is displayed in the status bar. Dual
Redundancy is not enabled by default and must be congured.
For a technical reference of the Ethernet Port, please refer to section 8.4. Additional information is also available in
the Lake Network Conguration Guide.
Note: When connecting multiple devices to an Ethernet network, care must be taken NOT to create a
closed loop which causes network malfunction.
5. Operation and performance
16
PLM+ SERIES Operation Manual rev 1.0.0
5. Operation and performance
This chapter provides comprehensive information on PLM+ Series connection, setup, operation and performance.
The detailed information included here is essential to realizing the full functionality of the PLM+ Series devices.
5.1. Operation precautions
Make sure that the Standby button on the PLM+’s front panel is either unlit (OFF), or red (STANDBY), before
making any input or output connections.
Ensure the AC voltage is within the range printed on the label adjacent to the AC mains connector.
Ensure no input signal is present when powering on the PLM+ to reduce the risk of any inadvertent bursts of high
level audio.
5.2. Power Output Performance
The PLM+ uses Lab.gruppen’s patented Class TD technology (Tracking Class D) in the output stages, which
couples the efciency of Class D topologies to the sonic purity of Class A/B designs.
The primary benet is that Lab.gruppen’s Class TD works perfectly under all load conditions. The output maintains
its at frequency response even into complex loads with very low nominal impedances. Reliability is very high,
and there is no interference with nearby RF equipment. Superior efciency allows greater power density while
minimizing cooling requirements, yet sound quality matches that of the best Class A/B designs.
5.2.1. Symmetrical Power
The PLM+ models can deliver power as shown in Table 5.1 when all channels are driven equally.
Table 5.1: Symmetrical Load Power Ratings
Load Impedance (ohms)
2 ohms
(per channel)
2.67 ohms
(per channel)
4 ohms
(per channel)
8 ohms
(per channel)
16 ohms
(per channel)
PLM 12K44 300 0 W 300 0 W 300 0 W 1900 W 950 W
PLM 20K44 4400 W 5000 W 4400 W 2300 W 1150 W
5. Operation and performance
PLM+ SERIES Operation Manual rev 1.0.0
17
5.2.2. Rational Power Management™
Rational Power Management™ (RPM) is a unique Lab.gruppen feature that allows for exible allocation of power
across channels of a PLM+. Power that is not used by one output channel is free for use by another output
channel with greater demands. RPM allocates power up to the total limits of the specic amplier model. RPM
exists in two modes. See the image below.
PLM+ Series - Amp channels power adjusted to match the loudspeaker requirements
3000 W
MIDSUB
LOW
HIGH
Figure 5.2: PLM 12K44 - Amp channels power adjusted to match the loudspeaker requirements
Auto RPM: The frame will automatically allocate power per output channel according to the ISVPL settings in the
speaker preset (per module output) in Lake Controller. If the ISVPL settings taken together allow total output higher
than the capabilities of the amplier, RPM will reduce the ISVPL limiter thresholds evenly based on a proportional
reduction in dB. When RPM is active, an RPM icon will be displayed next to the “Actual ISVPL” values in the
Events & Control section. If actual ISVPL is above the normal platform maximum and equals speaker threshold, the
RPM indicator will be green. If actual ISVPL is above normal platform maximum but below speaker threshold, the
RPM indicator will be yellow.
Custom RPM: The CAFÉ software allows users to create an advanced custom power allocation scheme.
Switching to Custom mode disables the Automatic mode. When RPM is active an RPM icon will be displayed
next to the “Actual ISVPL” values in the Events & Control section. Please nd more information about this in
documentation supplied with the CAFÉ software download.
RPM limitations: PLM 20K44 allows all four channels to deliver Channel Max output voltage of 194V.
PLM 12K44 allows two channels to deliver Channel Max output voltage of 194V.
5. Operation and performance
18
PLM+ SERIES Operation Manual rev 1.0.0
CAFÉ with ESP: CAFÉ (Conguring Ampliers For the Environment) is a dedicated software application for
Windows and OSX that provides tools for system planning, specication and commissioning. CAFÉ incorporates
the Equipment Specication Predictor, a software module that examines SPL and speaker requirements for a
project and generates requirements for output power on an amplier and system level. For more information on
CAFÉ and ESP, please consult the documentation supplied with the CAFÉ software download.
5.3. Amplifier and Load Protection Systems
The PLM+ is equipped with a comprehensive set of protection circuits. If operating conditions become sufciently
extreme that any of these circuits become active, indication is provided by LEDs in one or more soft function
buttons 5-8, together with adjacent warning text. In addition to this, notication is also presented within the Lake
Controller software and within system log les.
5.3.1. Inter-Sample Voltage Peak Limiter (ISVPL)
The ISVPL is a high quality voltage limiter that can deliver seamless limitation to any desired level. Its ensures that
the voltage at the output terminals never exceeds the dened threshold.
It operates on these principles:
• The signal is delayed slightly to allow the ISVPL to look-ahead and reduce the gain before voltage in excess
of the threshold can appear at the output. This results in zero voltage overshoot at the output with a rounded
limitation up to the threshold.
• The amplitude of the output signal between digital samples is predicted which permits the ISVPL to respond to
analog peaks that may occur at the digital to analog converter.
• The release time of gain reduction is adaptive depending on the dynamics of the signal.
It is possible to select different ISVPL proles for limiting optimization for a specic frequency band and personal
preference. The proles are divided into two categories, with one category optimized for low distortion and the
other focusing on producing high sound pressure level (SPL). Within each category there are proles optimized for
the different frequency bands.
5.3.1.1. Low Distortion Profiles
• Universal – The universal prole is a soft limiter that can be used for all frequencies and is conservative in its
action upon VCL and CPL.
• Sub/LF – The Sub/LF prole is tuned for frequency bands below 600 Hz. It has longer attack and release times
and is less conservative when it comes to acting upon VCL and CPL.
•
5.3.1.2. High SPL Profiles
High SPL proles do not use the adaptive release time feature. High SPL proles optimized for high frequencies
use less of the look-ahead delay peak-rounding feature; this feature is used most in the Sub prole and least the
HF prole.
• Sub - The Sub prole is optimized for frequencies between 20 - 200 Hz
• LF - The LF prole is optimized for frequencies between 20 - 1200 Hz
• MF - The MF prole is optimized for frequencies between 300 - 6000 Hz
• HF - The HF prole is optimized for frequencies above 1 kHz
5. Operation and performance
PLM+ SERIES Operation Manual rev 1.0.0
19
Table 5.3 shows the theoretical maximum output power for a given load impedance and ISVPL setting.
Note: An ISVPL-to-load calculator that will assist in generating the appropriate ISVPL setting for a desired
power load is available at www.labgruppen.com/plm. The ratings shown in the table below are limited by the
CPL (Current Peak Limiter) functions, not by ISVPL settings, due to power output channel current capacity.
Max. Sinewave Burst Power (Watts)
LLoad Impedance (ohms)
2 2.67 4 8 16
LISVPL SETTING (V peak)
194 4489 5993 4705 2352 1176
193 4489 5993 4656 2328 1164
181 4489 5993 4095 2048 1024
167 4489 5223 3486 174 3 872
153 4489 4384 2926 1463 732
121 3660 274 2 183 0 915 458
101 2550 1910 1275 638 319
83 1722 1290 861 431 215
70 1225 918 613 306 15 3
56 784 587 392 19 6 98
47 552 414 276 138 69
38 361 270 181 90 45
17.8 79 59 40 20 10
Table 5.3: ISVPL-to-output examples
The ISVPL threshold may be set at any level between 17.8 V and 600 V via the PLM+’s menu system. For further
details, please refer to section 7.11.2.5 of this manual, and also to the PLM+ Series chapter in the Lake Controller
User Manual.
PLM+ devices that have a smaller peak output voltage can still set the ISVPL threshold up to 600 V. When a
threshold is set above the maximum capability of a power output channel, the maximum ISVPL for that product will
be automatically set. Therefore, the ISVPL threshold can be in at the Module for the speaker’s maximum capability,
and the Module le remains cross-compatible with all PLM and PLM+ Series devices.
5.3.2. Current Peak Limiter (CPL)
The output Current Peak Limiter (CPL) ensures that the power output section will not be damaged by forcing it to
deliver current levels at the outputs that exceed the maximum current ratings of the output transistors. The CPL
keeps the output transistors within their Safe Operating Area (SOA). The CPL is non-adjustable.
CPL activity is indicated on the power output channel LED (embedded in the associated output channel’s function
button to the right of the LCD). Activity on an affected channel results in a ashing red indication together with a
CURRENT CLIP warning message displayed on the screen adjacent to the LED. A warning is also displayed on
the controlling PC via the network.
5. Operation and performance
20
PLM+ SERIES Operation Manual rev 1.0.0
This condition indicates an attempt to draw excessive current at the output. The output is attenuated until the
output current falls below the maximum current rating. Limiting is performed by the ISVPL limiter in conjunction
with the selected ISVPL prole. Please refer to the Technical Specications in Section 11 for further details
regarding ratings.
Note: If excessive current is indicated, check the output cables and examine the loudspeaker. If
impedance appears normal, you may rectify the condition by altering the ISVPL settings or lowering
input levels. CPL indication can be triggered by excessively low output impedance, possibly the result
of too many loudspeaker cabinets connected in parallel.
5.3.3. Power Average Limiter (PAL)
PAL activity is indicated by all four LED’s to the left adjacent to the display ashing red, together with a PAL ACTIVE
warning message displayed on the screen. A warning is also displayed on the Lake Controller software.
The Power Average Limiter Active warning (PAL Active) will be displayed when the power supply’s maximum rated
design parameters are reached. When this warning is displayed, gain limiting is being applied to the signal and the
ISVPL threshold is lowered accordingly.
5.3.4. Breaker Emulation Limiter (BEL™)
The PLM+ ampliers are powerful devices that can draw a considerable amount of current from the mains supply.
The BEL models the temperature in the external breaker and limits the mains current to prevent it from tripping.
The BEL can be congured with both a breaker prole and a current value. The current value can be set from 5 to
32 Arms.
There are three different proles available for selection:
• Conservative - The conservative prole allows no momentary current above the congured threshold.
• Fast - The fast prole models the time constant of the trip-curve corresponding to a fast breaker. It momentarily
allows current above the threshold to pass for a short time, leading to an increased modeled temperature. For
the limiter to disengage, the current must reduce below the threshold to enable the breaker to cool down.
• Universal - The universal prole models the time constant of the trip-curve corresponding to a slow breaker.
It momentarily allows current above the threshold for a longer time, leading to an increased modeled
temperature. For the limiter to disengage the current has to reduce below the congured current for the breaker
to cool down.
The BEL can be congured via the PLM+ front panel and within the Lake Controller software.
5. Operation and performance
PLM+ SERIES Operation Manual rev 1.0.0
21
5.3.5. Under Voltage Limiter (UVL™)
PLM+ devices are equipped with an under voltage limiter. With mulitple powerful devices on a mains distribution
line, heavy current loads risk the reduction of voltage below that required for devices to function. The UVL
reduces the mains current draw when voltage drop below 80 V. The amount of reduction applied increases as
mains voltage drops towards 65 V, then at 65 V the power supply is shut down. The mains supply is continually
monitored and when sufcient voltage returns the power supply automatically restarts.
5.3.6. Current Average Limiter (CAL™)
The Current Average Limiter (CAL) monitors the RMS current drawn from each power output channel to ensure
that the power output stages are not overloaded. When activated, it regulates the current to a safe level to protect
the channel. The CAL should not be activated in normal usage, but if it is, its operation is indicated by an active
LED and the message CAL ACTIVE. Further indication is given within the Lake Controller software.
5.3.7. Voltage Clip Limiter (VCL)
If current draw from the PLM+’s power supply is too high, the PSU’s regulation capability may be exceeded and
the internal voltage rails may drop and cause clipping. If this occurs the VCL acts rapidly to prevent clipping on
the subsequent peaks. Limiting is performed by the ISVPL limiter in conjunction with the selected ISVPL prole.
Indication of this condition is shown on the output LEDs.
5.3.8. Temperature Protection
5.3.8.1. Overview
PLM+ Series devices are equipped with a sophisticated temperature sensing system that provides protection from
overheating which may occur as a result of inadequate ventilation or excessive power output.
Thermal measurements are made at several points within each power output channel along with measurements
in the power supply and DSP areas. If temperature in any area reaches a critical level then a warning is displayed
and gain reduction is applied. If the temperature continues to increase and reaches a dangerous level then a fault
is displayed and audio is muted. Each power output channel, the power supply and DSP area have separate
indications.
For all temperature faults, temperature monitoring will continue at 0.5 second intervals, with the output remaining
muted. When the area has cooled below the dangerous threshold, the fault condition is cleared and audio is
restored.
5. Operation and performance
22
PLM+ SERIES Operation Manual rev 1.0.0
5.3.8.2. Power Output Channels
A power output channel temperature warning or fault is indicated in one of the front panels LEDs (in the right-hand
soft function buttons).
• A warning is indicated by a static yellow LED and adjacent warning message: TEMP WARN:CH
• A fault is indicated with a static red LED and adjacent warning message: TEMP FLT:CH
An event report is sent to the Lake Controller software for both the warning and the fault. If a temperature fault
condition arises on a power channel, the output of that channel will be muted.
5.3.8.3. Power Supply / DSP
A power supply (PSU) or DSP temperature warning or fault is indicated by the LEDs in the four left function buttons
being lit at the same time.
• A warning is indicated by static yellow LEDs and adjacent warning message: TEMP WARN:PSU
(or TEMP WARN:DSP)
• A fault is indicated with static red LEDs and adjacent warning message: TEMP FLT:PSU (or TEMP FLT:DSP)
At temperatures above the critical warning level and below the dangerous fault level, the ISVPL threshold is slowly
reduced to decrease the output power and cool down the device. This enables the device to continue to pass
audio, although with a reduced amplitude, in extreme conditions. If reducing the ISVPL threshold does not cool
down the device a temp fault will still be issued when the dangerous temperature level is reached. An event report
will be sent to the Lake Controller software for both the warning and the fault.
5.3.9. DC Protection
DC protection is implemented on each power output to prevent damage to connected loudspeakers or any
PLM+ components. DC present at the output will cause the PLM+’s power output module breaker to blow. In this
instance a red LED will illuminate and NEEDS SERVICE will display on the LCD.
Note: The power output channel modules are independent of the input voltage. This is not a userservicable fault condition and the unit should be returned for repair.
5.3.10. VHF Protection
The PLM+ includes protection circuits that detect Very High Frequency (VHF) content in the input signal. The
detection is frequency-dependent, initiated from 10 kHz upwards. If continuous VHF signals are detected above
the threshold, the output will mute for approximately 6 seconds before a further measurement is taken. When
continuous VHF signal stops, the output unmutes and the amplier returns to normal operation.
5. Operation and performance
PLM+ SERIES Operation Manual rev 1.0.0
23
This protection system recognizes only continuous VHF signals at high levels that will not appear in speech or
music. Any such content can therefore be considered as a fault condition. VHF protection is essential to avoid
damage to HF drivers.
VHF protection is dependent on a combination of output power level and frequency. Figure 5.4 shows a
decreasing power threshold, from approximately 10 kHz upwards, which illustrates increasing sensitivity of the
protection system with frequency. When continuous output power above the threshold line is detected, VHF
protection becomes active.
Trigger voltage
Voltage [Vrms]
100
90
80
70
60
50
40
30
20
10
0
0 5
10 15 20 25 30
Frequency [kHz]
Fig 5.4: VHF Protection Frequency Sensitivity
The attack time of the VHF protection circuitry also changes with frequency, becoming shorter at higher
frequencies. This is shown in Figure 5.5.
Full output voltage
Time [ms]
1400
1200
1000
600
800
400
20
200
0
0 5
10 15 20 25 30
Frequency [kHz]
Fig 5.5: VHF Protection Attack Time Variations
The VHF protection circuit is NOT a limiter and does not alter the PLM+’s frequency response. It is implemented
solely to detect continuous VHF content. HF content of normal music or speech signals at peak levels will be
passed in full.
Operation of the VHF protection circuits is indicated by one (or more) of the output channel LEDs (in the right-hand
soft function buttons) showing steady red. The adjacent fault message will show VHF FAULT. It is also reported as
a fault via the control network.
5. Operation and performance
24
PLM+ SERIES Operation Manual rev 1.0.0
5.3.11. Short Circuit Protection
A low impedance or short circuit at the power output terminals is detected when the output current is high (Current
Peak Limiter is active) and, simultaneously, the peak output voltage is below a predetermined threshold. When
this situation occurs, the output stage is muted to protect it from damage. Operation of the short circuit protection
system is indicated by an output channel LED (in the right-hand soft function buttons) showing steady red. The
adjacent fault message will show SHORT CIRCUIT. It is also reported as a fault via the control network to the Lake
Controller software. The presence of a short circuit (or low impedance) is re-tested every six seconds, and the
output remains muted until the fault clears.
5.4. Power Supply
The R.SMPS (Regulated Switch Mode Power Supply) is designed to keep supply voltage rails at optimum levels
even when the mains voltage drops. Mains voltages can drop as much as 20% below nominal before there is any
effect on rail voltages. Thus the R.SMPS can deliver full rail voltage to the output stage at all times, allowing the
PLM+ to exhibit consistent transient response and a clean LF response. PLM+ features a universal power supply
with power factor correction (PFC). The device can accept any mains voltage, from 65 V to 265 V, allowing it to
function worldwide in many different congurations. The PFC reduces current peaks on the lines and reduces the
requirements placed on the mains distribution system. PLM+ units offer an unparalleled power factor extremely
close to one.
5.4.1. Low Inrush Current
High power ampliers with inadequate inrush current limiting can draw considerable current from the mains at turnon, sometimes tripping a fast-acting mains breaker. The PLM+, however, has very low inrush current to prevent
tripping of breakers.
Several PLM+s can, under normal conditions, be powered up simultaneously. If you do experience problems
powering up multiple PLM+s simultaneously, they must either be turned on manually in an ordered manner, or
sequenced remotely using the Lake Controller software’s Global Control feature. Alternatively, the capacity of the
mains supply should be increased.
Note: If insufcient power is available to allow simultaneous power-up, then there is probably insufcient
capacity for full power output during operation. It is recommended that additional capacity is added to
the mains power distribution system.
6. Signal Flow and Lake® Processing
PLM+ SERIES Operation Manual rev 1.0.0
25
6. Signal Flow and Lake® Processing
6.1. Signal Flow
The gures below depict the audio signal ow for a PLM+ Series device. It is worth noting that this sophisticated
device provides seven points in the signal chain where the signal level can be adjusted, muted or disconnected.
The blue sections represent Frame data, and the red sections represent Module data - please refer to the Lake
Controller Operation Manual for further information.
Important information regarding correct setting of the gain structure can be found in section 10.3.
INPUTS
Dante Receivers 1-8
AES 1-4
Analog 1-4
OUTPUTS
Dante 1-8
(no mutes)
AES/Analog
pass through
to Dante
Input
Routers
1-4
WITH
INPUT
MUTES
Input
Mixer A
Input
Mixer B
Input
Mixer C
Input
Mixer D
Lake Contour
Module A
Attenuator
Mute
Phase Rev
Custom RPM
Lake Contour
Module B
Lake Contour
Module C*
Lake Contour
Module D*
ISVPL
Auto RPM
Amp Gain LoadSmart LoadPilot AMP
Attenuator
Mute
Phase Rev
Custom RPM
ISVPL
Auto RPM
Amp Gain LoadSmart LoadPilot AMP
Attenuator
Mute
Phase Rev
Custom RPM
ISVPL
Auto RPM
Amp Gain LoadSmart LoadPilot AMP
Attenuator
Mute
Phase Rev
Custom RPM
ISVPL
Auto RPM
Amp Gain LoadSmart LoadPilot AMP
Module Data stored in Module FIles (Speaker Presets)
Frame Data stored in System Files and Frame Presets
Output Routing
1 2 43 5
Figure 6.1: PLM+ Signal Flow Diagram
6.2. Level Adjustments & Mute Points
1
Input Router Stage Input selection and MUTE
2
Input Mixer Stage Router on /off connection to mixer and gain settings
3
Module Input Stage Mute (N/A for LM Series Mesa Mode) and gain settings
4
Module Output Stage Mute and gain settings
5
Output Router Stage Output on /off routing connections
6
Attenuation Stage Power output channel mute and attenuation settings
7
Amp Gain Stage Amplier gain control
Note: If the required audio signal is not passing correctly, verify the connection, mute and gain settings
at all seven stages.
6. Signal Flow and Lake® Processing
26
PLM+ SERIES Operation Manual rev 1.0.0
6.2.1. Power Output Section: Limiting and Sensitivity
The Current Peak Limiter (CPL) dynamically limits the drive to the power stage based on three parameters: sensed
output current level, feedback from the output stage, and sensed voltage clip from the ISVPL. This ensures that
power output is maintained within the design limits of the PLM+.
The adjustable Inter-Sample Voltage Peak Limiter (ISVPL) sets the PLM+’s maximum output voltage and therefore
also the maximum output power. The ISVPL setting is made via MENU > MODULE > LIMITERS > ISVPL, and can
also be set from the Lake Controller software.
The sophisticated output section monitors faults and generates warnings when appropriate; warnings are
displayed on the front panel of the PLM+ and also sent as messages over the control network. In the rare event
that maximum ratings are signicantly exceeded, the PLM+ will mute until the condition has been rectied or
the incorrect setting has been readjusted. Sensing circuits also transmit local output power stage temperature,
processor card temperature, and PSU temperature to the appropriate protection circuits. Please refer to section
5.3 further details.
Table 6.2 lists PLM+ Series analog input sensitivity in dBu and Vrms for various Amp Gain settings and maximum/
minimum ISVPL settings, assuming an analog input headroom of 26 dBu.
Table 6.2: Analog Input Sensitivity in dBu and Vrms
6.3. Lake Processing and Control
As outlined in section 2.2.3, this device integrates seamlessly into the Lake Processing environment, providing all
features, functionality and connectivity associated with all Lake Processors. The internal Lake Processing includes
programmable crossovers, EQ, dynamics and other functions, and can be fully controlled via the Lake Controller
software with a version number of 6.3 or later. Additionally, many functions can be controlled or accessed directly
via the front panel.
The Lake Controller Operation Manual and Lake Network Conguration Guide are supplied on the accompanying
USB key and additional documentation is available from the Start Menu after software installation.
Visit http://labgruppen.com to download the latest software, rmware and documentation for your devices.
Input Sensitivity
LISVPL SETTING
194 V 17.8 V
LGAIN (dB)
+44 +1.0 0.87 -19.8 0.08
+41 +4.0 1.22 -16. 8 0.11
+38 +7.0 1.73 -13 .8 0.16
+35 +10. 0 2.44 -10.8 0.22
+32 +13. 0 3.45 -7. 8 0.32
+29 +16 .0 4.87 -4.8 0.45
+26 +19 .0 6.88 -1. 8 0.63
+22 +23.0 10 .90 +2 .2 1.00
6. Signal Flow and Lake® Processing
PLM+ SERIES Operation Manual rev 1.0.0
27
6.4. Modules and Frames
6.4.1. Overview
A Frame represents one physical Lake Processor device (e.g. PLM 12K44). A maximum of four Modules are
contained within each Frame; these are referred to as Module A, B, C and D. The number of Modules shown in a
given Frame is dependent upon the signal processing conguration of that Frame.
Each Module can be congured as a Classic Crossover (Bessel, Butterworth, Linkwitz-Riley), as a Linear Phase
Crossover, or as multiple full bandwidth Auxiliary Outputs. The default conguration for the PLM+ is 4 x Contour
Classic 1 Way (CL1-Way) Output Modules, providing a total of twelve Module outputs that can be routed to any of
the four power outputs.
Please refer to the Lake Controller Operation Manual for further information.
6.4.2. LoadLibrary™ and Fingerprints
In addition to the standard loudspeaker presets (Module les), the Lake Controller also includes a set of enhanced
Module les specically for use with the PLM and PLM+ Series.
These supplementary PLM+ Module les, known as the LoadLibrary, incorporate both Lake DSP parameters along
with PLM+ specic data; LoadLibrary Module les include parameter settings for the Amplier Gain and ISVPL
limiter. Additionally, LoadLibrary loudspeaker types may also include data relating to the electrical characteristics of
a particular loudspeaker.
Electrical characteristic data is used to enable load verication (LoadSmart) to be performed on the PLM+.
This data set is termed a Fingerprint. When a PLM+-specic loudspeaker type is loaded, its Fingerprint load
characteristics are included. These load characteristics are stored in a le with a “.mdl” sufx and are loaded
simultaneously with the module le.
6.5. Loudspeaker Processor Overview
The Lake Processing system within PLM+ Series devices may be congured with up to four processing Modules
containing a total of up to twelve processing Module outputs, that can be routed to any of the four power output
channels.
Each set of processing elements is referred to as a Module and can be congured as crossovers, full bandwidth
auxiliary outputs, or a combination of the two. The relationship between inputs and outputs is dened via the Lake
Controller or via the front panel Input Cong Menu.
The Lake Processing system provides two distinct categories of crossovers:
• Innite Impulse Response lters (IIR) such as the classic Bessel, Butterworth or Linkwitz-Riley types; these are
available with slopes ranging from 6 dB/octave to 48 dB/octave.
• Finite Impulse Response lters (FIR) providing zero phase shift with steep transition slopes at the crossover
frequencies. These are also referred to as Linear Phase Crossovers.
Notes
6. Signal Flow and Lake® Processing
28
PLM+ SERIES Operation Manual rev 1.0.0
6.6. Files and Presets
The Lake system provides various methods for storing and recalling Module, Frame, or system-wide data. An
overview is provided below; for further information please refer to the Lake Controller Operation Manual.
6.6.1. Module, System and Sub-System Configuration Files
Module, System and Sub-System Conguration les are stored on the Lake Controller PC, and data is passed
across the network when recalling or storing these type of les.
• A Module le is the smallest set of data that can be stored and recalled; it contains crossover, gain, delay, and
limiter information for an individual loudspeaker (see Figure 6.1).
A Module le may be recalled into other Lake devices. It is not possible to store a Module File directly on
the hardware device.
• A System or Sub-System Conguration File contains a set of Module le information in addition to Frame
related information such Group data and I/O conguration (see Figure 6.1).
6.6.2. Frame and System Presets
The entire processor conguration can be stored as a Frame Preset on this hardware device. Presets can be
recalled via the front panel (refer to section 7.11.7) or via the Lake Controller software or Preset Manager utility;
presets can be stored using the Lake Controller software or Preset Manager utility.
A maximum of 100 Frame Presets can be stored on this device. The data within a Frame Preset includes the
congurations of all Modules in the Frame, including levels, crossover, EQ, input mixer, routing, and all other
parameters. As Frame Presets are stored in the hardware device, recall is available without using a PC.
Using the System Presets function in the Lake Controller, entire system congurations can be stored and recalled
across a network of LM, PLM and PLM+ Series devices. This enables fast retrieval and switching of entire system
congurations as minimal data is being sent between the Controller and Processors.
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