Lab.gruppen PLM Series User manual
Rev. 1.0.5
Item no. OM-PLM
Operation Manual
PLM™Series
Powered Loudspeaker Management™systems
2 PLM Series Operation Manual
1 CONTENTS
1 CONTENTS...................................................................................................................................................2
2 APPROVALS ................................................................................................................................................6
3 WARNINGS .................................................................................................................................................6
3.1 Explanation of Graphical Symbols .......................................................................................................6
3.1.1 WARNING ................................................................................................................................6
3.1.2 CAUTION..................................................................................................................................6
3.2 Important Safety Instructions ..............................................................................................................6
3.3 User responsibility ...............................................................................................................................7
3.3.1 Mains connection grounding ....................................................................................................7
3.3.2 Speaker output hazard..............................................................................................................7
3.3.3 Radio interference ....................................................................................................................7
3.3.4 Speaker damage.......................................................................................................................7
3.3.5 Maintenance.............................................................................................................................7
4 WELCOME...................................................................................................................................................8
4.1 Introduction .........................................................................................................................................8
4.2 Main Features......................................................................................................................................8
4.2.1 Amplifier platform.....................................................................................................................8
4.2.2 Amplifier DSP: Gain, ISVPL™, load verification and performance monitoring..........................8
4.2.3 Dolby®Lake®Processing and Controller ..................................................................................8
4.2.4 SmaartLive®integration............................................................................................................9
4.2.5 Dante™audio network ..............................................................................................................9
4.3 Additional Documentation ...................................................................................................................9
5 INSTALLATION .........................................................................................................................................10
5.1 Unpacking..........................................................................................................................................10
5.2 Mounting ...........................................................................................................................................10
5.3 Rear Mounting ...................................................................................................................................10
5.4 Cooling...............................................................................................................................................11
5.5 Operating Voltage ..............................................................................................................................12
5.6 Grounding ..........................................................................................................................................12
6 PLM SERIES FEATURES ..........................................................................................................................13
6.1 Front Panel overview .........................................................................................................................13
6.2 Rear Panel overview ..........................................................................................................................15
6.2.1 Input connectors and Links ....................................................................................................15
6.2.2 Output connectors..................................................................................................................16
6.2.3 Network connectors...............................................................................................................16
6.2.4 AC input..................................................................................................................................16
6.3 Integrated Dolby Lake Processing .....................................................................................................17
6.3.1 Dolby Lake Controller (DLC) PLM Edition software ...............................................................17
7 OPERATION AND PERFORMANCE ........................................................................................................18
7.1 Introduction to Operation...................................................................................................................18
7.1.1 Operation precautions ............................................................................................................18
7.2 Power Output Performance...............................................................................................................18
7.2.1 Symmetrical power ................................................................................................................18
7.2.2 Asymmetrical power ..............................................................................................................18
7.2.3 Power over time .....................................................................................................................18
7.3 Amplifier and Load Protection Systems ............................................................................................19
7.3.1 Inter-Sample Voltage Peak Limiter (ISVPL) ............................................................................19
7.3.2 Current Peak Limiter (CPL) .....................................................................................................20
7.3.3 Power Average Limiter (PAL) .................................................................................................20
PLM Series Operation Manual 3
CONTENTS 1
7.3.4 Current Average Limiter (CAL)..................................................................................................20
7.3.5 Voltage Clip Limiter (VCL) .........................................................................................................20
7.3.6 Temperature protection.............................................................................................................20
7.3.7 DC Protection............................................................................................................................21
7.3.8 VHF Protection..........................................................................................................................21
7.3.9 Short circuit protection..............................................................................................................21
7.4 Power Supply.....................................................................................................................................22
8 SIGNAL FLOW AND PROCESSING.........................................................................................................23
8.1 Signal Flow .......................................................................................................................................23
8.1.1 Level adjustments ..................................................................................................................23
8.1.2 Mute points ............................................................................................................................23
8.1.3 Power Output section: Limiting and sensitivity......................................................................23
8.2 Loudspeaker Processor Configuration...............................................................................................24
8.3 Modules and Frames .........................................................................................................................25
8.3.1 LoadLibrary™ and Fingerprints...............................................................................................25
8.3.2 Super Modules .......................................................................................................................26
8.4 Presets...............................................................................................................................................26
8.4.1 Module files............................................................................................................................26
8.4.2 Frame Presets ........................................................................................................................26
8.4.3 Subsystem Presets.................................................................................................................26
8.4.4 System Presets ......................................................................................................................26
9 FRONT PANEL INTERFACE .....................................................................................................................27
9.1 Front Panel Navigation.......................................................................................................................27
9.1.1 General description of navigation in the PLM.........................................................................27
9.1.2 Pinging Modules in the DLC PLM Edition software from the PLM .......................................27
9.2 Key Lock Front Panel .........................................................................................................................28
9.3 Power button ....................................................................................................................................28
9.4 Mute Enable Button ..........................................................................................................................28
9.5 Meter Button ....................................................................................................................................28
9.6 Menu Button .....................................................................................................................................28
9.7 Network Activity LED .......................................................................................................................29
9.8 Rotary Encoder .................................................................................................................................29
9.9 Exit Button ........................................................................................................................................29
9.10 Soft Function Buttons ...................................................................................................................... 30
9.10.1 Mute functions ....................................................................................................................... 30
9.10.1.1 PLM Input Mute............................................................................................................ 30
9.10.1.2 Module Input Mute....................................................................................................... 30
9.10.1.3 Module Output Mute.....................................................................................................31
9.10.1.4 Power Output Mute.......................................................................................................31
9.10.2 LED Faults, warnings and clip indications...............................................................................31
9.10.2.1 Green indications ...........................................................................................................32
9.10.2.2 Yellow indications..........................................................................................................32
9.10.2.3 Red indications ..............................................................................................................32
9.11 Warning and Fault Indications........................................................................................................... 33
9.12 Meter Mode...................................................................................................................................... 34
9.12.1 Meter view 1 – Home View................................................................................................... 35
9.12.2 Meter View 2 – Module View................................................................................................ 35
9.12.3 Meter View 3 – Temperature View........................................................................................ 36
9.13 Menu Mode .......................................................................................................................................37
9.13.1 Menu View .............................................................................................................................37
9.13.2 Module submenu .................................................................................................................. 38
4 PLM Series Operation Manual
9.13.2.1 Gain .............................................................................................................................. 38
9.13.2.2 Delay ............................................................................................................................ 38
9.13.2.3 Phase Reverse ............................................................................................................. 38
9.13.2.4 Amp Gain...................................................................................................................... 38
9.13.2.5 Limiters ........................................................................................................................ 38
9.13.2.5.1 Inter-Sample Voltage Peak Limiter (ISVPL) .......................................................... 39
9.13.2.5.2 MaxPeak Level (MaxPeakLvl) .............................................................................. 39
9.13.2.5.3 MaxRMS Level (MaxRMSLvl).............................................................................. 39
9.13.2.5.4 MaxRMS Corner (MaxRMSCor) .......................................................................... 39
9.13.5.5.5 MaxRMS Attack (MaxRMSAtk) ........................................................................... 39
9.13.2.5.6 MaxRMS Release (MaxRMSRel)......................................................................... 39
9.13.2.6 Mutes ........................................................................................................................... 39
9.13.3 Input Routing and Settings submenu .................................................................................... 40
9.13.3.1 Input selection and sensitivity settings ........................................................................ 40
9.13.3.2 IsoFloat™ ......................................................................................................................41
9.13.3.3 AES/EBU input termination...........................................................................................41
9.13.4 Attenuation submenu..............................................................................................................42
9.13.5 Frame submenu ......................................................................................................................42
9.13.5.1 Frame Name ..................................................................................................................42
9.13.5.2 Frame Info .....................................................................................................................42
9.13.5.2.1 Firmware version (‘FW version’)........................................................................... 43
9.13.5.2.2 Latency (‘Inh. Latency’)........................................................................................ 43
9.13.5.2.3 Max Output Voltage (‘MaxOutVolt’)..................................................................... 43
9.13.5.2.4 Max Output Current (‘MaxOutCurr’).................................................................... 43
9.13.5.2.5 Serial Number (‘Serial no.’)................................................................................... 43
9.13.5.3 Frame Reset ................................................................................................................ 43
9.13.5.3.1 Factory Reset ....................................................................................................... 43
9.13.5.3.2 Soft Reset ............................................................................................................ 43
9.13.5.4 Network........................................................................................................................ 43
9.13.5.4.1 IP Address ............................................................................................................ 44
9.13.5.4.2 MAC Address....................................................................................................... 44
9.13.5.4.3 Frame ID .............................................................................................................. 44
9.13.5.4.4 Network statuses (‘Online’) ................................................................................. 44
9.13.5.4.5 IP Mask ................................................................................................................ 44
9.13.5.5 Latency match.............................................................................................................. 44
9.13.5.6 Display adjustments ..................................................................................................... 44
9.13.5.6.1 Display Contrast ................................................................................................... 44
9.13.5.6.2 Dimming............................................................................................................... 44
9.13.6 Frame Preset submenu.......................................................................................................... 44
9.13.7 LoadSmart™ .......................................................................................................................... 44
9.13.7.1 Configure # of cabinets in parallel ................................................................................. 45
9.13.7.2 LoadSmart verification.................................................................................................. 45
9.13.8 Dante...................................................................................................................................... 45
9.13.8.1 Using the PLM as a “break-in box” .............................................................................. 46
10 BACK PANEL INTERFACE ........................................................................................................................47
10.1 Power inlet.........................................................................................................................................47
10.1.1 PowerCon® wiring details.......................................................................................................47
10.2 Audio Input and Links ........................................................................................................................47
10.2.1 Analog inputs and Links ..........................................................................................................47
10.2.1.1 Unbalanced operation ....................................................................................................47
10.2.1.2 Iso-Float electronic balancing ....................................................................................... 48
1 CONTENTS
PLM Series Operation Manual 5
10.2.2 Digital inputs and Links.......................................................................................................... 48
10.3 Speaker Output Connections............................................................................................................ 49
10.3.1 Speakon output connectors ................................................................................................... 49
10.3.2 Binding Post output connectors ............................................................................................ 50
10.4 RJ45 connectors............................................................................................................................... 50
11 APPENDIX .................................................................................................................................................51
11.1 Faults and Warnings Overview..........................................................................................................51
11.2 Maintenance ..................................................................................................................................... 54
11.3 Factory Default Settings ................................................................................................................... 54
11.4 Current Draw and Thermal Dissipation Specifications ..................................................................... 55
11.5 Glossary of Terms, Acronyms and Abbreviations............................................................................. 56
12 APPLICATION GUIDE .............................................................................................................................. 69
12.1 I/O Panels ......................................................................................................................................... 59
12.2 Power Distribution ............................................................................................................................ 59
12.3 Gain Structure................................................................................................................................... 60
12.3.1 Gain / Level optimization.........................................................................................................61
12.4 Speaker Configurations..................................................................................................................... 65
12.5 Connecting Digital Audio Devices .................................................................................................... 65
12.5.1 AES/EBU digital audio ............................................................................................................ 65
12.5.2 Sampling rates and latency.................................................................................................... 65
12.5.3 Interconnecting digital audio .................................................................................................. 66
12.5.4 Digital audio cabling recommendations ..................................................................................67
12.5.5 Accessories ............................................................................................................................67
12.5.5.1 Passive splitters.............................................................................................................67
12.5.5.2 Distribution amplifiers ...................................................................................................67
12.5.6 Application hints .....................................................................................................................67
12.6 Digital Clock Configuration ............................................................................................................... 68
12.7 Firmware Upgrades .......................................................................................................................... 69
12.7.1 Firmware Upgrades Using the Update Utility ......................................................................... 69
12.7.2 Firmware Upgrades Using the Dolby Lake Controller PLM Edition ........................................71
12.8 Hot swapping PLM devices...............................................................................................................72
13 TECHNICAL SPECIFICATIONS ................................................................................................................73
14 WARRANTY ..............................................................................................................................................74
CONTENTS 1
6 PLM Series Operation Manual
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 approved according to the U.S. safety standard ANSI/ UL 60065 and Canadian safety standard CSA C22.2 NO. 60065. ETL
made the tests and they are a Nationally Recognized Testing Laboratory (NRTL).
3.1 Explanation of Graphical Symbols
The lightning symbol within a triangle is intended to alert the user to the presence of un-insulated “dangerous voltages” within the unit’s chassis that may be of
sufficient magnitude to constitute a risk of electric shock to humans.
The exclamation point within a triangle is intended to alert the user to presence of important operating and service instructions in the literature accompanying the
product.
3.1.1 WARNING
3.1.2 CAUTION
3.2 Important Safety Instructions
Before using your PLM, be sure to carefully read the applicable items of this Operation Manual and the Safety Instructions.
1. Keep this manual for future reference.
Heed all warnings.2.
Follow all instructions.3.
Do not use this unit near water.4.
Do not spill water or other liquids into or on the unit. Do not operate the unit while wet or standing in liquid.5.
Clean only with dry cloth.6.
Do not block the air intake or exhaust ports. Install the unit in accordance with the instructions.7.
Do not operate the unit near heat producing devices such as radiators, heat registers, stoves or other apparatus that produce heat. Always operate the unit with the chassis ground wire connected to the8.
electrical safety earth. Do not defeat the safety purpose of a grounding-type plug. A grounding-type plug has two pins and a third grounding prong. The third prong is provided for your safety. If the provided
plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
Connect only to AC power outlets rated 100 -120 V or 200 -240 V, 50- 60 Hz as dictated by the unit’s voltage configuration.9.
Do not use this unit if the power cord is broken or frayed. Protect the power cord from being walked upon or pinched, particularly at the plug and the point where it exits from the apparatus.10.
Only use accessories specified by the manufacturer.11.
The unit is intended to use in a 19” rack. Follow the mounting instructions. When a rack on wheels is used, use caution when moving the loaded rack to avoid injury from tipping over.12.
Unplug this apparatus during lightning storms or when unused for long periods of time.13.
Do not connect the unit’s outputs in parallel or series with any other unit’s output. Do not connect the unit’s output to any other voltage source, such as battery, mains source, or power supply, regardless14.
of whether the unit is turned on or off.
Do not run any of the unit’s outputs back into another channel’s input.15.
Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way such as:16.
Power-supply cord or plug is damaged.▸
Liquid has been spilled into the unit▸
An object has fallen into the unit▸
The unit has been exposed to rain or moisture▸
The unit does not operate normally▸
The unit was dropped or the chassis is damaged▸
17. Do not remove top or bottom covers. Removal of the covers will expose hazardous voltages. There are no user serviceable parts inside and removal may void the warranty.
18. An experienced user shall always supervise this professional audio equipment, especially if inexperienced adults or minors are using the equipment.
19. The mains plug is used as the disconnect device and shall remain readily accessible. If the mains plug is not readily accessible due to mounting in a 19” rack, then the mains plug for the entire rack must be
readily accessible.
20. The US National Differencescl.16.3 requires that network cables must be flame rated VW-1.
2 APPROVALS
To reduce risk of fire or electric shock, do not expose this apparatus to rain or moisture.
Do not expose this system/apparatus to dripping or splashing and ensure that no objects filled with liquids, such as vases, are placed on the apparatus.
L’appareil ne doit pas être exposé à des egouttements d’eau ou des éclaboussures et de plus qu’aucun objet rempli de liquide tel que des vases ne doit pas être
placé sur l’appareil.
This apparatus must be connected to a mains socket outlet with a protective
earthing connection.
Cet appareil doi t être raccordé á une prise de courant qui est branchée à la terre.
The mains plug is used as a disconnect device and shall remain readily operable.
Lorsque la prise du réseau d’alimentation est utilisés comme dispositif de déconnexion, ce dispositif doit demeuré aisément accessible.
To reduce the risk of fire or electric shock, do not remove screws. No user-serviceable parts inside. Refer servicing to qualified service personnel
3 WARNINGS
PLM Series Operation Manual 7
WARNINGS 3
3.3 User Responsibility
3.3.1 Mains connection grounding
Your PLM must be connected to a grounded
socket outlet.
3.3.2 Speaker output hazard
PLMs are capable of producing hazardous
output voltages. To avoid electrical shock, do
not touch any exposed speaker wiring while the PLM
is operating. The external wiring connected to the
speaker terminals shall be installed by a qualified
person, or ready-made leads or cords of appropriate
capacity shall be used.
As the power output channels produce high
voltage, do not connect or disconnect speaker
cables when the mains power is on.
3.3.3 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 B 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
fields, high voltage flashes, and radio inter-
ference.
Consult the dealer or an experienced radio/TV▸
technician for help.
3.3.4 Speaker damage
Your PLM Series device 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 PLM’s
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.
3.3.5 Maintenance
For safe and reliable operation, the dust covers behind
the front panel should be cleaned regularly. If the dust
filters are not maintained there will be safety risks.
For example the unit can ignite the dust and a fire
will occur due to high internal temperatures. There
is also a risk that the unit will malfunction since it is
dependent on constant airflow from front to rear. If
the dust filters are not clean and the unit malfunc-
tions, any resultant problems will not be covered by
the warranty.
8 PLM Series Operation Manual
4 WELCOME
4.1 Introduction
Thank you for choosing the Lab.gruppen PLM Series
of Powered Loudspeaker Management systems for
your sound reinforcement needs. We are confident
that you will be pleased with the performance, unique
features, configuration flexibility, reliability, and long-
term durability offered by PLM Series products.
To facilitate timely installation and use of this PLM
Series product, your welcome package includes a
printed copy of the PLM Series Quick Start and Field
Reference Guide. It contains the basic information
needed to safely install a PLM system and place it in
service. Control and editing features are accessible
either via the intuitive front panel interface or remotely,
with the included Dolby Lake Controller PLM Edition
software package.
We do, however, highly recommend reading through
all of the product documentation on the included CD
ROM in their entirety. As you become thoroughly
familiar with the many configuration and control
options available in PLM Series products, you may
learn about features and options that will affect your
choices of operational modes or loudspeaker system
configurations.
Thank you again for placing your confidence in
Lab.gruppen products.
4.2 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 benefits of each feature,
and gives a reference to the corresponding section
in this or other manuals.
4.2.1 Amplifier platform
The PLM Series amplifier section is built on the
foundation of Lab.gruppen’s robust, road-proven
FP+ Series. Features in common with the FP+ Series
include extraordinary power density, patented Class
TD® output stages, Regulated Switch Mode Power
Supply (R.SMPS™), the high-efficiency Intercooler®
copper-finned cooling system, and a full suite of
protection features. Signal inputs are analog, AES
digital, and Dante digital audio network; loop-through
outputs or redundant pairs are provided for each input
type. (See section 6.2.)
4.2.2 Amplifier DSP: Gain, ISVPL, load
verification and performance monitoring
Input gain (sensitivity) is set in the digital domain
in the PLM Series, controllable through the DLC
PLM Edition software or the front-panel interface.
The DSP-implemented Inter-Sample Voltage Peak
Limiter (ISVPL) tailors each power output to the
characteristics of the connected load. (See section
7.3 .1.)
The on-board DSP also implements a comprehensive
set of proprietary tools developed by Lab.gruppen
for load verification 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 then
compares actual-to-predicted response, identifying
any malfunctioning components or connection errors.
During the actual performance, SpeakerSafe™
monitors real-time load status, including amplifier,
loudspeaker voice coil and magnet temperatures;
this allows operators to avoid power compression
and identify potential problems. (See the Dolby Lake
Controller User Manual PLM Edition Addendum
for more detailed information on PLM Series load
verification and real-time performance monitoring
functions.)
4.2.3 Dolby Lake Processing and Controller
The PLM Series integrates seamlessly into the
Dolby Lake processing environment. Two processing
modules offer precise settings for gain, delay,
crossover slope, equalization and limiting. Dolby Lake
processing features incorporated in each module
include Raised Cosine Equalization, linear phase
crossovers, and LimiterMax™ loudspeaker protection.
The Super Module feature allows hardware processing
modules in two or more separate PLM Series units
to function as a single module in the Dolby Lake
Controller PLM Edition software interface. (See
section 8.2 and the separate Dolby Lake Controller
User Manual.)
4.2.4 SmaartLive integration
The Dolby Lake Controller PLM Edition enables
PLM Series Operation Manual 9
seamless, plug-in integration of the industry-standard
SmaartLive analysis system. With this feature,
operators can measure with SmaartLive and make
EQ adjustments at the same time, using the same
software controller on a Wi-Fi enabled Tablet PC. (See
the separate Dolby Lake Controller User Manual.)
4.2.5 Dante audio network
All PLM Series products include Dante digital
audio networking as standard. Based on the latest
advances in networking, Dante offers simplified
system configuration and extremely low latency
while delivering very high quality uncompressed
digital audio over the entire PLM Series network.
The Zen™ automatic configuration feature enables
“plug-and-play” setup without third-party DHCP or
DNS servers. Dante is fully compatible with new
high-bandwidth network backbones, allowing high
channel counts while also transporting third-party
control protocols through the same network.
4.3 Additional Documentation
This document, the PLM Series 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
configuration of internal features using the front-panel
interface.
However, if you intend to use the PLM Series unit(s)
as part of networked systems, or access monitoring
and control features via the Dolby Lake Controller
PLM Edition software application, then you may need
to refer to the following complementary documents.
All are available on the included CD-ROM or online
at http://www.labgruppen.com/index.php/support/
product_documentation/
PLM Series Quick Start and Field Reference Guide
– This document provides basic information needed
to unpack, install, and access basic feature sets of
the PLM Series. A printed copy is included with
your unit.
PLM Series Network Configuration Guide – This
document provides detailed information on creating
networks of PLM Series units, with sample network
topologies and specific recommendations for third-
party networking devices.
Dolby Lake Controller User Manual PLM Edition
Addendum – This document covers those features
and functions that are unique to the PLM Edition of
the Dolby Lake Controller software application.
Dolby Lake Controller Manual – This document
provides detailed information on features and
functions of Dolby Lake Controller exclusive of
features unique to the PLM Series. It is available
both on the included CD-ROM or via download at:
http://www.dolby.com/professional/live_sound/
support_download/documentation.html.
WELCOME 4
10 PLM Series Operation Manual
loom bends within a rack. In particular, the mains
cable (AC cord) and its Neutrik PowerCon connector
require at least 120 mm (4.75 inches) clear rack depth
behind the PLM rear panel. The PLM Series products
have no top or bottom vents; PLM’s may be stacked
directly on top of each other. It may be desirable to
include a 1U spacer between PLMs to permit more
convenient rear panel wiring.
5.3 Rear Mounting
Two rear support brackets, plus mounting hardware,
are included with the PLM (figure 5.3a). It is
recommended that these are used wherever possible.
They should be fitted to vertical rack rails at the rear
of the rack. Refer to figures 5.3b and 5.3c for details
of their installation.
Note that the support brackets are reversible and
may be fitted to point either to the front or rear of
the rack. The orientation used in a particular situation
will depend on the depth of the rack and the position
of the rear rack rails.
x2
x2 x2x2
Figure 5.3a: Rear support mounting hardware
Two mounting methods are possible; note that the
method shown in figure 5.3b additionally provides
extra security against unauthorized removal.
5 INSTALLATION
5.1 Unpacking
Carefully open the shipping carton and check for any
damage to the PLM Series product 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, the shipping carton should
contain the following items:
PLM Series Quick Start and Field Reference
▸
Guide
AC mains lead (power cord)▸
Rear brackets for additional rack support (pair)▸
Mounting hardware for above▸
CD-ROM containing:▸
Dolby Lake Controller PLM Edition software and*
firmware
PLM Series Operation Manual*
PLM Series Network Configuration Guide*
Dolby Lake Controller User Manual*
Dolby Lake Controller User Manual PLM Edition*
Addendum
Release Notes*
PLM Series Technical Data*
PLM 10000Q A&E Specifications*
We recommend that you keep the original carton and
all other packaging materials to facilitate shipping of
the PLM should the need arise.
5.2 Mounting
Airflow for cooling the PLM is from front panel
(intake) to rear panel (exit). There must be nothing
at the front or rear of the rack in which the PLM is
mounted – such as doors or lids - to impede the
airflow.
Note that there must always be sufficient space at
the rear of the PLM to permit efficient air exit (see
section 5.4) and to accommodate rear connectors
and cables; allowance must be made for cable or
PLM Series Operation Manual 11
For situations where rapid removal and replacement
of units is of paramount importance, the method
shown in figure 5.3c may be used as it does not
involve any permanently secured fixing at the rear
of the unit.
Figure 5.3c: Use tube for slide-on installation
Figure 5.3b: Use washer for xed installation
5.4 Cooling
The PLM uses a forced-air cooling system with
airflow from front to rear, allowing high continuous
power levels without thermal problems. (Front-to-rear
airflow 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 airflow. The operation
of the PLM’s cooling system is dependent on front-
to-rear airflow; it will not function effectively with
airflow 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
sufficient space to allow the exit air to escape. If the
PLM is rack-mounted, never operate the unit with
any front or rear rack doors or covers in position.
Also note that any unused rack spaces should have
solid blanks fitted (not ventilation blanks) to ensure
efficient air circulation. Leaving gaps in between
items of equipment degrades the effectiveness of
forced-air cooling.
If installing one or more PLM’s in a rack with other
fan-cooled equipment, be sure that all the other
units also use front-to-rear airflow for cooling. If
this precaution is not observed, there is a risk of
overheating, as units with the reverse airflow will
be drawing in air which has already been heated by
the PLMs.
The PLM is equipped with a sophisticated
temperature sensing system which protects
it from any overheating which may occur
as a result of inadequate ventillation. Should
a power output channel overheat, the temperature
sensing circuits will mute that channel until the
temperature reduces to a safe level. If the power
supply overheats, another sensing circuit will mute
will reduce the overall output level of all channels in
an effort to bring the PSU temperature down. If a
problem still exists, a sensing circuit will mute the
power output channel that has the highest temperature
reading, thereby reducing the overall temperature of
the power supply until it reduces to a safe operating
level.
Always make sure that the dust filters behind the
detachable front panel are clean to ensure maximum
possible airflow.
INSTALLATION 5
12 PLM Series Operation Manual
If the device malfunctions as a result of
dirty dust filters, any required repairs are
not covered by the warranty.
5.5 Operating Voltage
The label adjacent to the mains (AC) input
connector indicates the AC mains voltage for
which the amplifier is wired and approved. The
amplifier is built in two versions: 115 V and 230 V.
Connect the mains cable (AC cord) only to an AC
source of the voltage shown on the label.
Any damage resulting from a PLM Series
product being connected to an AC source
of incorrect voltage will not be covered by
the warranty.
The PLM uses primary switching, which means the
mains power is rectified 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.
If the mains plug (AC plug) fitted to the mains cable
(AC cord) is not appropriate for your country, it can
be removed and a locally-sourced one fitted instead,
observing the color coding in the table below:
PowerCon Pin 230 V Version 115 V Version
LBrown Black
NBlue White
Green/Yellow Green
Table 5.5: AC plug conguration
If you are not 100% confident of your compe-
tence to replace the mains plug (AC plug), the
task should be carried out by qualified personnel.
Once a suitable AC supply is connected, the PLM
can be turned on using the front panel power switch.
When the unit is switched on, the PLM goes through
a soft-start sequence as it performs a diagnostic
routine on the internal circuitry. The fans will run at
high speed for a short period before dropping to idle
speed, and the power symbol in the power switch will
change from red (Standby mode) to green (active).
In-rush current is controlled and limited during
the soft-start sequence, enabling multiple
PLMs on the same AC mains circuit to be
powered up simultaneously.
5.6 Grounding
Analog inputs feature Iso-Float ground isolation,
a technology which combines the benefits of
transformer-coupled isolation with the advantages
of clean, direct-coupled inputs.
The audio converters are galvanically isolated, and
not connected to the main ground. High-speed
transformers and opto-isolators create a barrier
between the PLM and the outside electrical
environment.
The Iso-Float feature is activated by default,
but may be disabled via the supplied Dolby
Lake Controller PLM Edition software, or
via the PLM’s front panel menu system.
In the interests of safety, NEVER disconnect the earth
(ground) pin on the mains cable (AC power cord).
Use correctly-shielded balanced audio input
connections to minimise hum and interference. Refer
to section 10.2.1 for more information.
5 INSTALLATION
PLM Series Operation Manual 13
QUICK GUIDE OVERVIEW 6
The front panel controls, clustered around a 2.5”
daylight readable LCD, perform most control and
monitoring functions via a simple menu system. The
two switch clusters on either side of the LCD include
dedicated function keys as well as eight “soft keys”
(functions vary according to current display page) and
a rotary data encoder.
Handles
Two sturdy metal handles are fitted to the front panel.
The handles always should be used when carrying
the PLM, and when fitting it in or removing it from
a rack. Ensure that any door or removable rack front
cover has sufficient depth to clear the handles.
Dust filters
Two dust filters are fitted behind metal covers. To
remove the covers, loosen the thumbscrews located
behind the handles. Once detached, the dust filter
elements can be removed for cleaning. See section
11.2 for information on cleaning the dust filters.
The device never should be operated
without the dust filters in place.
Display
The display illuminates when the PLM is active.
Many of the control and metering functions found
on conventional amplifiers are replaced on the PLM
by a set of on -screen pages which, together with the
soft keys and rotary encoder, allow monitoring and
control of operating parameters. Multicolor LEDs
embedded in the soft keys display fault and warning
status indications.
6.1 Front Panel Overview
The layout of various display “pages” is standardized
to a high degree for ease of use. In general, each
page is divided into two columns of four blocks,
with the left-hand column referring to inputs and
the right-hand to outputs. Each block has four rows
of data, which can be either alphanumeric or in the
form of a bargraph meter.
The brightness of the display and the adjoining
network activity LED can be adjusted in the Frame
page of the Main menu.
Comprehensive details of the various display pages
and the associated controls are given in section 9 –
Front Panel Interface.
Standby
The PLM is powered on and off by the top left-most
button, STANDBY. See Dolby Lake Controller User
Manual PLM Edition Addendum (sections 5.3.1 and
5.7) for further information regarding local and remote
power control.
Mute Enable
Select MUTE ENABLE to allow muting via the soft
function buttons of the inputs to the Dolby Lake
system, the power output channels, or both. The
MUTE ENABLE legend in the button flashes when
the mode is selected. A second press will deselect
the mode; however, if left active, MUTE ENABLE
mode will automatically cancel after two minutes if
no further mute actions are taken.
Meter
The METER button scrolls through three alternative
views: HOME, MODULE, and TEMPERATURE.
PLM SERIES
3
4
5
67
8
9
10 11
12
1 1
2 2
Figure 6.1: PLM front panel layout
14 PLM Series Operation Manual
QUICK GUIDE OVERVIEW 6
Pressing METER when in MENU mode returns the
screen to METER mode, and the HOME view is
displayed.
The display has two basic operating
modes: METER (default) and MENU.
Menu
Pressing the MENU button puts the screen display
into MENU mode, and the “top” page of the MENU
“tree” is displayed. Once in MENU mode, the function
buttons enable the user to navigate the menu tree
and access most PLM Series operating functions.
See sections 9.12.2 to 9.12.8 for more details.
Soft Function Buttons
Eight soft function buttons are set adjacent to the
display in two groups of four. These buttons are
unlabelled because their functions change according
to the current menu mode as displayed on the
screen. In MENU mode they are used to navigate
the menu tree and for the selection of parameters
to edit. In METER mode they will act in conjunction
with the MUTE ENABLE feature.
Status LEDs
Eight tricolor LEDs are integrated into the soft function
buttons for convenience. These convey both fault and
warning indications, plus the currently selected mute
status of the Dolby Lake Processing system inputs
and the output channels. Full details can be found
in section 9.10.
High-intensity LED
A white, high-intensity LED is located to the right
of the display. This LED illuminates when the PLM
Series’ control system is being accessed remotely via
the DLC PLM Edition software. Steady illumination
of the white LED indicates that the unit is selected
in the DLC PLM Edition software; a flashing white
LED indicates a change in parameters or operating
state.
The brightness of the display and the adjoining
network activity LED can be adjusted in the Frame
page of the Main menu.
Encoder
The rotary encoder is used to modify various PLM
parameters (e.g. input level) in the leaf nodes of
the menu tree. When a menu item is selected that
permits adjustment of parameter values, the ring
around the knob illuminates.
Exit
The EXIT key is used primarily while navigating the
menu system in MENU mode; pressing it takes the
display back to a previous screen (“up one level” in
the menu tree). In METER mode, pressing the EXIT
key always returns the display to the HOME view.
PLM Series Operation Manual 15
6 QUICK GUIDE OVERVIEW
6.2.1 Input connectors and Links
See section 10 for full details of
connector pinouts, etc.
Analog inputs
Analog inputs are available on two standard XLR3F
latching connectors. The inputs are electronically
balanced and feature Dolby’s patented Iso-Float
circuitry. The impedance is 20 kOhms, and the inputs
can accept a maximum input level of +26 dBu.
Analog links
Two latching XLR3M connectors are fitted adjacent
to the analog input connectors. These are paralleled
to the input connectors to provide an unprocessed
analog loopthrough to feed additional PLM Series
units, or other equipment.
AES/EBU inputs
A latching XLR3F connector is provided which accepts
an AES/EBU digital audio signal. Input impedance is
110 ohms.
The AES/EBU digital audio format is two-
channel, and thus both PLM inputs are fed
via a single connector. Selection of the
analog or digital inputs is made via the front
panel display or control software.
In comparison to analog signals, digital audio
signals such as AES/EBU require quite
different cabling and routing techniques. In
particular, standard XLR “mic cables” - even
high-quality ones - are rarely suitable for digital audio.
Always use 110 ohm digital audio cables. See sections
10.2.2 and 12.5 for further information before making
any connections to the AES/EBU inputs.
AES/EBU link
A latching XLR3M connector is fitted adjacent to
the AES/EBU input connector. This is paralleled
to the input connector to provide an unprocessed
AES/EBU loop-thru to feed further PLMs, or other
equipment. An AES/EBU 110 ohm termination load
is enabled by default when the PLM is the last unit
connected within an AES/EBU daisy-chained system.
The termination may be disabled, if desired, via the
front panel menu and within the DLC PLM Edition
software.
6.2.2 Output connectors
The PLM is available with a choice of connectors for
power outputs: binding posts or Neutrik Speakon.
Bridge mode operation: The PLM is capable
of bridge-mode operation, however the
present system management software
does not support this mode and therefore
bridged operation is NOT recommended.
6.2 Rear Panel Overview
Ser. N:o
Removed!
CH 2
CH
CH 4
CH 3
CLASS 2 WIRING
SPEAKER OUTPUTS
INPUT
INPUT 2LINK
LINK 2
AES/EBU
INPUT 1-2 LINK 1-2
LINK SECPRIMACT LINKACT
SWITCHED 10/100 Base-TX
Must be grounded/earthed
Made in Sweden
PIN 1: SCRN 2: POS 3: NEG
ANALOG WITH
I
SO-
F
LOAT
TM
200-240V 2500W
50-60Hz
PLM
0000Q
1
Ser. N:o
Removed!
CLASS 2 WIRING
SPEAKER OUTPUTS
INPUT
INPUT 2LINK
LINK 2
AES/EBU
INPUT 1-2 LINK 1-2
LINK SECPRIMACT LINKACT
SWITCHED 10/100 Base-TX
Must be grounded/earthed
Made in Sweden
PIN 1: SCRN 2: POS 3: NEG
ANALOG WITH
I
SO-
F
LOAT
TM
1+/- CH 1+/-
2+/- CH 2+/-
1+/- CH 1+/-
2+/- CH 2+/-
3+/- CH 3+/-
4+/- CH 4+/-
1+/- CH 3+/-
2+/- CH 4+/-
200/240V 2500W
50-60Hz
PLM
0000Q
1
1234
5
6
789
12
Figure 6.2: PLM rear panel layout
16 PLM Series Operation Manual
6 QUICK GUIDE OVERVIEW
Please contact plmsupport@labgruppen.com for
further information on bridge-mode operation.
Binding posts
In this version, the power outputs for loudspeaker
connection are available on four separate pairs of
fully-enclosed binding posts.
Speakon connectors
In this version, the power outputs are simultaneously
available on a single 8-pole Neutrik Speakon
connector, and on two 4-pole Neutrik Speakon
connectors. The two 4-pole connectors carry the
outputs of channels 1 & 2 and 3 & 4 respectively.
The table below shows the proper wiring scheme
for these Speakon outputs.
Pin
No.
NL4 #1 Chs.
1 & 2
NL8 Chs.
1 - 4
NL4 #2 Chs.
3 & 4
1+ Ch. 1 o/p + Ch. 1 o/p + Ch. 3 o/p +
1- Ch. 1 o/p - Ch. 1 o/p - Ch. 3 o/p -
2+ Ch. 2 o/p + Ch. 2 o/p + Ch. 4 o/p +
2- Ch. 2 o/p - Ch. 2 o/p - Ch. 4 o/p -
3+ Ch. 3 o/p +
3- Ch. 3 o/p -
4+ Ch. 4 o/p +
4- Ch. 4 o/p -
Table 6.2.2: Speakon wiring and pinouts
6.2.3 Network connectors
The two Neutrik RJ45 EtherCon®connectors
permit integration into an Ethernet control network
encompassing multiple PLM Series units as well as a
PC running the DLC PLM Edition software. Network
connection permits full control of all PLM functions,
and monitoring of all PLM operating parameters, from
a remote position. The PLM Series also supports
the Dante audio networking protocol, which allows
transmission of multichannel, high-definition digital
audio over the same Ethernet connection.
The Ethernet ports automatically switch to
operate at the two standard Ethernet data
rates of 10Base-T and 100Base-T, and also
allow either “crossed” or “straight” network
cables to be used. Two LEDs above each port indicate
connection to a valid network (LINK) and network
activity (ACT).
Full information on how to connect the PLM to a
network is contained within a separate document,
the PLM Series Network Configuration Guide.
Primary connector
Use this connector when the network is a simple
“star” configuration, consisting of individual Cat-5e
connections between PLMs and a local Ethernet
switch. Alternatively it can be used to connect to
the Secondary connector of another PLM within a
network, thus forming a daisy-chain topology.
Secondary connector
The secondary network connector can be used as a
loop-through to daisy-chain multiple PLMs into the
network. Alternatively, system security can be greatly
increased by using a dual-network topology. In this
case, the Secondary connector is connected to an
alternative Ethernet distribution system employing
a second set of switches, thereby ensuring full
redundancy and no single point-of-failure in the case
that Dante is used and a switch or cable fails. Further
information on PLM network configurations can be
found in the PLM Series Network Configuration
Guide.
When connecting multiple PLMs to an
Ethernet network, care must be taken NOT
to create a ring (closed loop) with the PLM
Ethernet ports. Ethernet by default will not
suppor t a ring topology; creating a ring will cause the
network to malfunction.
6.2.4 AC input
Mains connector
AC input to the PLM is via a Neutrik PowerCon
connector, rated at 32 A.
PLM Series Operation Manual 17
6 QUICK GUIDE OVERVIEW
The Dolby Lake Controller PLM Edition software is
easily installed by inserting the CD in the computer’s
CD drive and allowing the auto-setup routine to
run. Select INSTALL then Dolby Lake Controller
software from the installation window to initiate
installation. For most installations, the subsequent
suggested default paths can be accepted.
Please note that, if pre-existing DLC presets
are present on your PC when you install the
DLC PLM Edition software, choosing a
specific installation path may be preferable.
See the DLC User Manual PLM Edition Addendum
for more information.
Refer to chapter 2 of the DLC User Manual for further
details on how to install the software and configure
your computer for optimum performance.
Minimum recommended computer specifications
are:
Intel® Pentium® 1 GHz or faster.▸
512 MB RAM or greater.▸
128 MB Video RAM or greater.▸
Windows XP or Vista.▸
DirectX® 8.1 or later (pre-installed with Windows
▸
XP and Vista).
100Base-T wired Ethernet adapter and/or 802.11g
▸
wireless Ethernet adapter.
XGA display screen with min. resolution of 1024
▸
x 768 pixels.
If you are unsure about installing new software on
a PC, please contact your organisation’s IT Dept., or
another suitably qualified specialist first.
Once the software is installed, the application can be
launched by clicking the desktop icon created during
the install process in the usual way.
Full details of how to use the software application
are contained in the DLC User Manual and DLC User
Manual PLM Edition Addendum, both of which are
supplied with the PLM on an accompanying CD ROM
and available from the Start Menu.
6.3 Integrated Dolby Lake
Processing
As outlined in Section 4, PLM Series products
contain a fully integrated Dolby Lake loudspeaker
management system, providing many of the features
available as standard in the Dolby Lake Processor
(DLP) stand-alone unit. The Dolby Lake system within
the PLM provides fully-programmable crossovers,
EQ, dynamics and other functions, and is controlled
via the supplied DLC PLM Edition software. (See
section 6.3.1.) Additionally, some functions of the
Dolby Lake system can be accessed from the PLM’s
front panel screen.
Setting up the integral Dolby Lake system via the
DLC PLM Edition software includes selecting the
basic PLM configuration, including input mixers, input
format (analog or digital, etc.), crossover configuration
and output routing.
A full description of how the DLC PLM Edition
software is used with the PLM is contained in the
separate documents: The DLC User Manual and the
DLC User Manual PLM Edition Addendum.
Also see the accompanying PLM Series Network
Configuration Guide for details of how to connect
one or more PLMs to a PC via the Dante digital
audio network.
6.3.1 Dolby Lake Controller (DLC) PLM Edition
software
The CD-ROM supplied with the PLM contains the
Dolby Lake Controller PLM Edition software package.
This should be installed on any PC(s) that are to
be used to control and monitor the PLM(s). In a
touring situation where multiple networked PLMs
are involved, this will generally be a Tablet PC.
Figure 6.3.1 : DLC PLM Edition installation screen
18 PLM Series Operation Manual
7 OPERATION AND PERFORMANCE
7.1 Introduction to Operation
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.
7.1.1 Operation precautions
Make sure that the Standby button on the PLM’s
front panel is either unlit, or is showing red (i.e., the
PLM is in STANDBY mode), before making any input
or output connections.
Make sure that the AC voltage is correct and
matches that printed on the label adjacent to
the AC mains connector.
Make sure that no signal is present at the input to the
PLM when powering it up to prevent any inadvertent
bursts of high level audio.
7.2 Power Output Performance
The PLM uses Lab.gruppen’s patented Class TD
technology in the output stages, which couples the
efficiency of Class D topologies to the sonic purity
of Class 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 B designs.
7.2.1 Symmetrical Power
The PLM 10000Q can deliver power as per table 7.2.1
when all four channels are driven equally.
Load
Impedance
(ohms)
2.0 2.7 4 8 16
Max.
Output
power
(Watts)
2350 2700 2300 1200 660
Table 7.2.1: Symmetrical load power ratings
7.2.2 Asymmetrical power
The PLM 10000Q can deliver power as per table
7.2.2 when two channels are driven 3 dB lower than
the other two.
Table 7.2.2: Asymmetrical load power ratings
7.2.3 Power over time
Power ratings given above are applicable to the
example PLM 10000Q running at these levels for a
period of 60 minutes. Due to thermal considerations
in the power supply and elsewhere, it is possible
to draw higher power levels for a shorter period
of time. The graph below illustrates how the rated
power figures are derived and the higher short-term
capability.
Peak output voltage at “max power burst”
Figure 7.2.3: Power rating levels over time
Load
Impedance
(ohms)
2.0 2.7 4 8 16
Max.
Output
power
(Watts)
2350 2900 2400 1200 660
PLM Series Operation Manual 19
OPERATION AND PERFORMANCE 7
Power ratings are based on a “real-life” duty cycle of
25 ms full power every 400 ms. Between bursts, a
lower signal level applies, such that the continuous
average power is 1/8th of the rated power.
In reality, when some channels are delivering less than
maximum rated power, energy reserves in the PSU
are available to permit other channels to deliver more
power. The graph shows the peak output voltage over
time for a continuous sine wave is applied.
If all four channels are driven with the same signal
into the same impedance (solid red line), then the rail
voltage (dotted red line) will drop faster than when
two channels are delivering “max power” (solid blue
line) and two channels are delivering “half power”
(solid orange line). This is termed asymmetric loading.
The rail voltage for this is the dotted blue line.
It can be seen that higher power output is available
for 25 ms bursts with asymmetric loading.
7.3 Amplifier and Load
Protection Systems
The PLM is equipped with a comprehensive set of
protection circuits. If operating conditions become
sufficiently 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, notification is also
presented within the Dolby Lake Controller PLM
Edition software and within system log files.
7.3.1 Inter-Sample Voltage Peak Limiter
(ISVPL)
The ISVPL is a high quality voltage limiter. Its purpose is
to ensure that the voltage at the output terminals never
exceeds the threshold which has been set. It operates
on two fundamental principles:
The signal is delayed slightly in order to allow
▸
the ISVPL to “look ahead” and reduce the gain
before any voltage in excess of the threshold can
appear at the output. This results in zero voltage
overshoot at the output.
The amplitude of the output signal “between”▸
digital samples is predicted. This permits the
ISVPL to respond to analog peaks that may occur
at the power output.
The table below represents the absolute maximum
output power that an individual PLM channel can
deliver at the given ISVPL setting and impedance
shown.
An ISVPL-to-load calculator that will assist in
generating the appropriate ISVPL setting for
a desired power load isavailable at www.
labgruppen.com/plm
Table 7.3.1: ISVPL-to-output examples
* Note that these ratings are limited by the CPL (Current
Peak Limiter) functions, not by ISVPL settings, due to
amplifier channel current capacity
The ISVPL threshold may be set at any level between
17.8 V and 153 V (model dependent) via the PLM’s
menu system. (See Section 9.12.2.5.1 or the Dolby
Lake Controller User Manual PLM Edition Addendum
for details.) Note that the maximum ISVPL setting
of 153 V is greater than the 150 V maximum peak
voltage available from the example PLM 10000Q.
Other models may differ. This is to accommodate
the small degree of production spread of maximum
output voltage that exists between PLMs. By
allowing a maximum ISVPL setting fractionally higher
than the maximum safe output voltage under any
condition ensures that severe clipping will never be
encountered.
MAX. SINEWAVE BURST POWER (Watts)
Load Impedance
(ohms) 2.7 4 8 16
ISVPL SETTING
(V peak)
153 (max.) 3365* 2926 1463 732
150 3365* 2813 1406 703
121 2742 1830 915 458
101 1910 1275 638 319
83 1290 861 431 215
70 918 613 306 153
56 587 392 196 98
47 414 276 138 69
38 361 181 90 45
17.8 (min.) 79 40 20 10
20 PLM Series Operation Manual
7 OPERATION AND PERFORMANCE
7.3.2 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 by the affected output channel
LED (one of the four LEDs in the soft function buttons
to the right of the display) flashing red 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.
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. (See section 13 – Technical Specifications for
further details concerning ratings.)
If excessive current is indicated, check the
output cables and examine the loudspeaker.
If impedance appears to be 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.
7.3.3 Power Average Limiter (PAL)
The Power Average Limiter (PAL) controls the AC
current into the power supply. Power consumption
is limited to the rated design parameters of the
power supply, ensuring that the PSU will never be
overloaded. Also, high-power products such as those
in the PLM Series can potentially draw more current
(with output devices still within safe operating areas)
than is allowed by the mains fuse.
Only the 230 V version is fitted with a fuse.
It is not possible to source fuses with sufficient
current capacity for the 115 V versions.
The PAL protection feature can help prevent the
supply’s external breaker from tripping within time
intervals of less than three minutes. For longer time
intervals, it is the responsibility of the user to ensure
that the average level of the audio is within limits that
ensure that the breaker doesn’t trip.
PAL activity is indicated by the LED within the first soft
button adjacent to the display flashing red, together
with a PAL ACTIVE warning message displayed on
the screen. A warning is also displayed on the DLC
PLM Edition software.
7.3.4 Current Average Limiter (CAL)
The Current Average Limiter (CAL) monitors the RMS
current drawn from each 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 DLC
PLM Edition software.
7.3.5 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.
This can cause clipping; if this occurs the Voltage
Clip Limiter acts rapidly to prevent clipping occuring
on the subsequent peaks. Indication of this condition
is shown on the output LEDs.
7.3.6 Temperature protection
Thermal measurements are made at several points
within each channel as well as on the power supply.
If the maximum permitted temperature is exceeded,
a high temperature warning is given. In the case
of an amplifier component overheating, this will
be indicated by one of the output channel LEDs
(in the right-hand soft function buttons) showing
steady red. The adjacent fault message will show
TEMP FLT:CH. In the case of the PSU overheating,
the fault is indicated by the top left soft button’s
LED turning steady red, and the adjacent on-screen
text displaying the fault message TEMP FLT:PSU.
In either case, a report is also sent via the control
network to the DLC PLM Edition software.
However, before the monitored components reach
their maximum permitted temperature, a warning is
given by the appropriate LEDs (as above) first turning
yellow and an adjacent warning message TEMP
WARN:CH being displayed. Again, a corresponding
message is sent via the network to the DLC PLM
Edition software.
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Lab.gruppen
Lab.gruppen PLM Series User manual
Lab.gruppen
Lab.gruppen PLM Series User manual
Lab.gruppen
Lab.gruppen PLM Series User manual
Lab.gruppen
Lab.gruppen PLM Series User manual
Lab.gruppen
Lab.gruppen PLM Series User manual
Lab.gruppen
Lab.gruppen PLM 20K44 User manual
Lab.gruppen
Lab.gruppen PLM Series User manual
