Lab.gruppen PLM 20K44 User manual

PLM+ SERIES
Powered Loudspeaker Management™ System
Operation Manual
Rev. 3.0.1
Item no. OM–PLM+PLM+ SERIES
Powered Loudspeaker Management™ System
Rev. 3.0
Quick Start Guide
PLM 20K44
PLM 12K44
PLM 5K44
Item no. QSG-PLM+SERIES
Incorporating technologies from
PLM 20K44
PLM 12K44
PLM 5K44
Incorporating technologies from

1. Important safety instructions
2
PLM+ SERIES Operation Manual rev 3.0.1
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 ampliers)
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 specied by the
manufacturer.
12. Use only with a cart, stand, tripod, bracket, or table specied
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 qualied 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
qualied 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 qualié 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 sufcient 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 3.0.1
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 qualied
service personnel.
Français: Pour réduire le risque d’incendie ou de choc
électrique, ne pas retirer les vis. Aucune pièce réparable par
l’utilisateur. Coner l’entretien àpersonnel qualié.
1.2.4. User responsibility
Mains connection grounding
Your amplier must be connected to a grounded socket outlet.
Speaker output hazard on amplifiers
Ampliers are capable of producing hazardous output
voltages. To avoid electrical shock, do not touch any exposed
speaker wiring while the amplier is operating. The external
wiring connected to the speaker terminals shall be installed
by a qualied person, or ready-made leads or cords of
appropriate capacity shall be used.
As the power output channels on ampliers 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
receiver.
• 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
Amplier 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 ampliers
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 airow 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 airow 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
4
PLM+ SERIES Operation Manual rev 3.0.1
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. Amplier and Load Protection Systems 18
5.4. Power Supply 24
5.5. LoadPilot Load Monitoring 25
6. Signal Flow and Lake® Processing 28
6.1. Signal Flow 28
6.2. Level Adjustments & Mute Points 29
6.3. Lake Processing and Control 30
6.4. Modules and Frames 30
6.5. Loudspeaker Processor Overview 31
6.6. Files and Presets 31
7. Front Panel Interface 32
7.1. Overview 32
7.2. Front Panel Key Lock 33
7.3. Power Button 33

Table of Contents
PLM+ SERIES Operation Manual rev 3.0.1 5
7.4. Mute Enable Button 34
7.5. Meter Button 34
7.6. Menu Button 34
7.7. Exit Button 34
7.8. Dynamic Buttons, Controls and LEDs 35
7.9. Warning and Fault Indications 40
7.10. Meter Mode 42
7.11. Menu Mode 46
8. Back Panel Interface 60
8.1. Speaker Outputs60
8.2. Analog Inputs 63
8.3. AES3 Digital Inputs 65
8.4. RJ45 etherCON Network Connections 65
8.5. Power Inlet 67
9. Appendix 68
9.1. Faults and Warnings Overview 68
9.2. Maintenance 71
9.3. Factory Default Settings 71
73
9.5. Glossary of Terms, Acronyms and Abbreviations 76
10. Application Guide 78
10.1. Rack I/O Panels 78
10.2. Gain Structure 78
10.3. Gain / Level Optimization 79
82
10.5. Digital Audio Connections 83
86
88
12. Warranty and Support 90
12.1. General 90
12.2. International Warranties 90
12.3. Technical Assistance and Service 90

2. Introduction
6 PLM+ SERIES Operation Manual rev 3.0.1
2. Introduction
2.1. Welcome
Thank you for choosing the Lab.gruppen PLM+ Series of Powered Loudspeaker Management systems for your
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 is reviewed to ensure familiarity with
the various configuration and control options.
2.2. Main Features
The PLM+ Series incorporates a number of sophisticated technologies to ensure the best possible performance
2.2.1. Amplifier Platform
The PLM+ Series also incorporates Lab.gruppen’s exclusive Rational Power Management (RPM), which allows
Any channel in either model is capable of delivering higher outputs than the average 25% of the total power.
requirements for touring loudspeaker systems.
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.
The PLM+ 20K44 and 12K44 amplifiers feature four channels of Lab.gruppen's unique and patented
Class TD®output stages, and high-efficiency Intercooler®copper-finned cooling system. The PLM5K44
uses a newly developed Class D technology design with increased efficiency and sustained sonic perfor-
mance. All models have a regulated Switch Mode Power Supply (R.SMPS™) with unparalleled Power Factor
Correction (PFC) extremely close to one, and a full suite of protection features including the Breaker Emulation
Limiter (BEL).

2. Introduction
PLM+ SERIES Operation Manual rev 3.0.1
7
2.2.2.1. Amplifier Gain
Amplier Gain is set in the digital domain for PLM+ Series devices, and may be controlled via the Lake Controller
software or front-panel interface.
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 verication and real-time performance
monitoring. These functions utilize Fingerprint les available for some loudspeaker presets in the Lake LoadLibrary.
The LoadLibrary compiles a comprehensive database for each loudspeaker component of the connected load,
usually one or more band-limited drivers in a multi-way system.
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 simplied system conguration and extremely low latency while delivering very high quality
uncompressed digital audio across the Lake network. The Zen™ automatic conguration feature enables plug-
and-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
8 PLM+ SERIES Operation Manual rev 3.0.1
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
For complete information on DSP configuration and operation using Lake Controller, please refer to the
Lake Controller Manual, available online at www.labgruppen.com/support.
For detailed information on configuration and operation of the power platform using CAFÉ, please refer to the guide
embedded in the software or to the CAFÉ Coach video series available on the Lab.gruppen
YouTube channel or via a link on www.labgruppen.com.
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
Please keep the original carton and associated packaging to facilitate shipping of the device should the need arise.
3.2. Mounting
top or bottom vents and therefore PLM+ units may be stacked directly on top of each other.
accommodate connectors and cables; allowance must be made for cable or loom bends within a rack.

3. Installation
PLM+ SERIES Operation Manual rev 3.0.1
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
10 PLM+ SERIES Operation Manual rev 3.0.1
3.3. Cooling
3.3.1. Overview
direction.
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.
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
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.
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. All PLM+ models incorporate a universal power supply operating from 65 V to 265 V, but with
UVL (Under Voltage Limiting) active below 80 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
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 3.0.1
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 Conguration
If you are not 100% condent of your competence to replace the mains plug (AC plug), the task should be carried
out by qualied 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 benets 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 230 V Cable 115 V Cable
LBrown Black
NBlue White
Green/Yellow Green

4. Product Overview
12
PLM+ SERIES Operation Manual rev 3.0.1
4. Product Overview
4.1. Front Panel Overview
The front panel presents the following amplier 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 sufcient 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, except when screen saver is active. 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 conrmation of Controller
communication, and indicate various faults and warnings. The display automatically returns to Home view if no
activity within two minutes.
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 with very low power output signal for
30 minutes. It will light up again at the push of any button, when the Lake Controller communicates with any frame
or when signal reaches above -20 dB on any power output. 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 3.0.1 13
5Mute 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 bu
a subsequent press deselects this mode. If left activated, MUTE ENABLE mode will automatically disable two
minutes after the last mute action.
6Meter
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.
7Menu– 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.
8Dynamic 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
eously when indicating frame faults (red) or
warnings (yellow). Please refer to section 9 for further details.
9Dynamic 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 MUTEENABLE
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
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
14 PLM+ SERIES Operation Manual rev 3.0.1
4.2. Rear panel
3 4 51
1 23
4
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
ANALOGWITH ISO- FLOAT TM
50-60Hz
100-240V 2400-2950W
Ser. N:o Removed!
CH 2
CH 1
CH 4
CH 3
SPEAKER OUTPUTS
CLASS 3WIRING
BRIDGE
BRIDGE
INPUT 4
SWITCHED 00/ 000 Base-TX1 1
1Gbps 1Gbps
LINK
ACT
LINK
ACT
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
75 6
Input Connectors
1Analog Inputs– Four analog inputs are available on standard XLR-3F connectors, electronically balanced and
featuring Lake Iso-Float circuitry. Impedance is 20 kohms; maximum input level is +26 dBu.
2AES3 Inputs– Two latching XLR-3F connectors accept four channels of AES3 digital audio. Input impedance
is 110 ohms; ensure that 110 ohm digital audio cablesare used.
Output Connectors
The PLM20K44 and PLM12K44 are Your device will be equipped with one of the two output connector options.
Both options allowfor BridgeMode operation, which isactivated in the Lake Controller software. Please refer
to the LakeController Operation Manual for more information. The PLM5K44isequipped with both binding posts
and speakON connectors, and does not support Bridge Mode operation.
3Binding Posts– Power outputs are available on four separate pairs of fully enclosed binding posts.
4speakON connectors – Power outputs are available simultaneously on a single 8-pole connector (PLM20K44
and PLM12K44 only) and on two 4-pole connectors. The four-pole connectors carry outputs for channels 1&2
and 3&4 respectively. For PLM5K44, connector 1 carries output channels 1 and 2, connector 2 carries channel 2,
connector 3 carries channel 3and 4, and connector4 carries channel 4.
INPUT 1 INPUT 2 INPUT 3
PIN 1: SCRN 2: POS 3: NEG
ANALOG WITH ISO-FLOAT TM
INPUT 4
Ser. N:o Removed!
AES/EBU SWITCHED 00/ 000 Base-TX1 1
INPUT 1-2 INPUT 3-4 SECPRIM
1Gbps 1Gbps
LINK
ACT
LINK
ACT
PLM 5K44
CH 2CH 1SPEAKER OUTPUTS
CH 2CH 1
1+/- CH 1+/-
2+/- CH 2+/-
1+/- CH 2+/-
CH 4CH 3
CH 4CH 3
CLASS 2
WIRING
1+/- CH 3+/-
2+/- CH 4+/-
1+/- CH 4+/-
Must be
grounded/
earthed
50-60Hz
100-240V
2400-2950W
3
1 2 5 6 4 7

4. Product Overview
PLM+ SERIES Operation Manual rev 3.0.1 15
Ethernet and Power Connectors
5Primary Network Connector– Theprimary 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 ofall functions along with real-time metering from a remoteposition. This device
supports theDante audio networking protocol for multichannel, high-definition digital audio over the same Ethernet
connection.
Usethe primary connector when using a star network topology, consisting of individual Cat-5e connections
between the devices and an Ethernet switch. Alternatively, this connectioncan beused todaisy chain directly to
another Lake Processor. The daisy chain topology should not be used with Dante.
Note: Do not create a closed loop when configuring multiple devicesin an Ethernet network; this will
cause a network malfunction.
6Secondary Network Connector – Thesecondary network connector can be used to daisy-chain multiple
PLM+ Series devices.Alternatively, a Dante dual-network topology can be created byconnecting all secondary
network connectors to a separateEthernet switch, ensuringfull redundancyin the event of a network component
failure.
7Mains Power Connector – AC mains input for the PLM20K44 and PLM12K44 is via a Neutrik powerCON
connector, rated at 32A. Connector mates with supplied AC mains cable. PLM5K44 uses a standard IEC locking
connector. See previous section on Operating Voltage for more information.

5. Operation and performance
16 PLM+ SERIES Operation Manual rev 3.0.1
5. Operation and performance
5.1. Operation precautions
Make sure that the Standby button on the unit’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 unit to reduce the risk of any inadvertent
bursts of high level audio.
5.2. Power output performance
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
5.2.2. Rational Power Management™
across channels of the PLM+ unit. Power that is not used by one output channel is free for use by another output
channels that can produce the maximum channel power of the largest model. Hence, by using RPM, it is possible
model.
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 3000 W 3000 W 3000 W 1900 W 950 W
PLM 20K44 4400 W 5000 W 4400 W 2300 W 1150 W
PLM 5K44 900 W 1250 W 1250 W 1250 W 700 W
The PLM20K44 and PLM12K44 use Lab.gruppen’s patented Class TD technology (Tracking Class D) in the output stages,
which couples the efficiency of Class D topologies to the sonic purity of Class A/B designs. The primary benefit is that
Lab.gruppen’s Class TD works perfectly under all load conditions. The output maintains its flat 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 efficiency allows greater power density while minimizing cooling requirements, yet
sound quality matches that of the best Class A/B designs. The PLM5K44 uses a newly developed Class D technology
design with increased efficiency and sustained sonic performance.

5. Operation and performance
PLM+ SERIES Operation Manual rev 3.0.1
17
Desired power can be specied in several domains: burst and peak power; peak and RMS voltage; and also
the speaker’s AES power rating. By specifying the nominal impedance of the load, the RPM algorithms have all
input data required to calculate resulting RPM settings. If the desired RPM settings taken together allow total
output higher than the capabilities of the amplier, RPM will reduce actual RPM conguration evenly based on a
proportional reduction in dB. Once applied, the RPM functionality will ensure that the channel is not delivering more
power than specied. The ISVPL limiter algorithm performs the actual limitation. As default, the smaller models in
the range have an RPM conguration detailing an equal shared power allocation cross the channels at a voltage
(default voltage limitation) given in the specication sheet. To prevent the risk of over allocating the power supply
for varying or incorrect load impedances, RPM has a limitation for the smaller models in the range of the number of
channels that can be lifted above the default voltage limitation. RPM can be congured in two modes.
PLM+ Series - Amp channels power adjusted to match the loudspeaker requirements
3000 W
MIDSUB LOW HIGH
Figure 5.2: 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. Auto RPM assumes a nominal impedance of the Load and
applies an approximate power allocation. Auto RPM is default for PLM+.
Custom RPM: The CAFÉ software allows users to create an advanced custom power allocation scheme.
Switching to Custom mode disables the Automatic mode. Additional information is available in documentation
supplied with the CAFÉ software download.

5. Operation and performance
18
PLM+ SERIES Operation Manual rev 3.0.1
CAFÉ with ESP: CAFÉ (Conguring Ampliers For the Environment) is a dedicated software application for
Windows and OSX that provides tools for system planning, specication and commissioning. CAFÉ incorporates
the Equipment Specication Predictor (ESP), a software module that examines SPL and speaker requirements
for a project and generates requirements for output power on an amplier and system level. ESP will generate a
custom RPM conguration optimizing the power allocation within the frame. 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 sufciently
extreme that any of these circuits become active, indication is provided by amber or red LEDs on the front panel,
and by text notications in the Lake Controller and CAFÉ software. Refer to section 9.1 for more information on
warnings and faults.
5.3.1. Inter–Sample Voltage Peak Limiter (ISVPL)
The ISVPL is a high quality voltage limiter that can deliver seamless signal limiting to any desired level. It ensures
that the voltage at the output terminals never exceeds the dened 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 proles for limiting optimization for a specic frequency band and personal preference. The
proles 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 proles optimized for the different
frequency bands.
5.3.1.1. Low Distortion Profiles
• Universal – The universal prole 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 prole 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 proles do not use the adaptive release time feature. High SPL proles optimized for high frequencies
use less of the look–ahead delay peak–rounding feature; this feature is used most in the Sub prole and least the
HF prole.
• Sub – The Sub prole is optimized for frequencies between 20 – 200 Hz
• LF – The LF prole is optimized for frequencies between 20 – 1200 Hz
• MF – The MF prole is optimized for frequencies between 300 – 6000 Hz
• HF – The HF prole is optimized for frequencies above 1 kHz

Lake-enabled amplifier devices (D Series Lake, PLM+, PLM) that have a smaller peak output voltage capability still
allow ISVPL speaker threshold settings up to 600 V. When a threshold is set above the current maximum capability
of a power output channel, the actual ISVPL will automatically be set to the maximum ISVPL for that channel.
channel and displayed in [ ]. Therefore, the ISPVL threshold can be set at the Module for the speakers’s maximum
capability, and the Module file remains cross-compatible with all Lake-enabled amplifier devices.
5. Operation and performance
PLM+ SERIES Operation Manual rev 3.0.1 19
Table 5.3 shows the theoretical maximum output power for a given load impedance and ISVPL setting.
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 1743 872
153 4489 4384 2926 1463 732
121 3660 2742 1830 915 458
101 2550 1910 1275 638 319
83 1722 1290 861 431 215
70 1225 918 613 306 153
56 784 587 392 196 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 in the Lake Controller software. For further
details, please refer to the Lake Controller User Manual.
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.
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
CPL activity is shown by red indication on the Power channel LED of the affected output channel and a
corresponding text description on the front panel in Lake Controller and CAFÉ software programs.
Refer to section 9.1 for more information on warnings and faults.
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. Operation and performance
20 PLM+ SERIES Operation Manual rev 3.0.1
5.3.3. Power Average Limiter (PAL)
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 output signal
and the ISVPL threshold is lowered accordingly.
PAL activity is shown by flashing yellow on the frame LEDs and a corresponding text description on the front and
in Lake Controller and CAFÉ software programs. Refer to section 9.1 for more information on warnings and faults.
5.3.4. Breaker Emulation Limiter (BEL™)
The BEL models the temperature in the external breaker and limits the mains current to prevent the breaker from
•
•
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.
•
momentarily allows current above the threshold for a longer time, leading to an increased modeled temperature.
5.3.5. Under Voltage Limiter (UVL™)
PLM+ devices are equipped with an under voltage limiter. With multiple, 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 drops below 80 V. The amount of reduction applied increases as mains
voltage drops towards 65 V; at 65 V the power supply is shut down. The mains supply is continually monitored and
value can be set from 1 to 32 Arms, though the PLM 12K44 will automatically limit at between 5-25 and the
PLM 5K44 between 2-15 Arms. Just as with ISVPL, the actual value is displayed in [ ]. The different models have
different maximum current capabilities as specifies in the specification sheet. Also, the smaller models can be
configured all the way up to maximum user range. When the nominal current is set above the model’s capabilities,
the actual current is set to the maximum capabilities of the unit. Therefore, the nominal current can be set for the
application and the configuration remains cross-compatible with all the models. There are three different profiles
available for selection:
The BEL is configured manually from the front panel with the Lake Controller or CAFÉ software. CAFÉs ESP
design aid can also predict the current consumption, with the exact speaker requirements, and propose a
safeguarding BEL configuration
BEL activity is shown by flashing yellow on the frame LEDs and a corresponding text description on the front panel,
in Lake Controller and CAFÉ software programs. Refer to section 9.1 for more information on warnings and faults.
UVL activity is shown by flashing yellow on the frame LEDs and a corresponding text description on the front panel,
in Lake Controller and CAFÉ software programs. Refer to section 9.1 for more information on warnings and faults.