Lab.gruppen PLM series Operation Manual page 83

Term Description
Floating
An analog balanced input or output is said to be floating when full electrical isolation exists between that input or output and the equipment
connected to it. Transformer-coupled inputs and outputs are inherently floating. Electronically balanced inputs and outputs can never be
truly floating, though better designs – such as found in the PLM - do mimic the characteristics of transformer-coupled designs to a high
degree.
Frame
Lake terminology for a physical unit containing a Lake processing system, i.e. a single PLM or Lake Processor.
Frame ID
An electronic identification 'label' which can be given to each Frame in an amplification system. Naming Frames in a large system is
desirable as it simplifies identification in the Lake Controller.
Frame Preset Frame Presets are a class of Presets within the Lake processing system. Up to 100 can be stored in the PLM itself, and each holds the
complete configuration of all Modules and the Modules' internal settings.
Hub A type of network interface device with multiple Ethernet ports. Data arriving at any port is sent to all others. Hubs have been largely
replaced by Switches.
Input level
The amplitude of an audio signal at the point where it is applied to the input of the PLM, or at the input of an intermediate stage within it. An
analog input signal level will be expressed in dBu's, while a digital input signal level in dBfS (dBs below digital clip level; fS = full-scale)
In-rush current
When power is applied to a piece of electronic equipment, the initial current taken by the PSU can be very high as the various capacitors in
the circuitry charge up. This is called the in-rush current. In the case of power amplifiers, which contain numerous very large capacitors, the
in-rush current can be enough to blow fuses or breakers. The PLM's PSU contains circuitry to control the in-rush current to prevent this.
Inverse video Text on the display screen is normally white on the blue background. When text is selected for adjustment, it appears in inverse video, as
blue on a white "highlighted' box.
IP address
Every item of equipment connected to an Ethernet network has a unique address called the IP address, so that data gets to the correct
place. IP addresses are written as four groups of three decimal numbers between 0 and 255. In a system consisting of PLM's and a Lake
Controller, they are assigned and detected automatically, so there should be no need for users to even be aware of them.
IP subnet mask IP subnet masks are required in all IP networks. The subnet is determined by the size and type of network being used. For small networks
(less than 254 addresses) a subnet mask of 255.255.255.0 can be used. (A Class C network).
Iso-Float Iso-Float is Lake's proprietary method of electronic balancing, which provides a particularly high level of isolation and immunity from ground
loops.
ISVPL
Short for Inter-Sample Voltage Peak Limiter. A proprietary Lab.gruppen technique for ensuring that the voltage at the output terminals of
an PLM does not exceed a pre-determined level.
Lake Controller
The Lake Controller is the software application used to control one or more PLM devices. This software application provides additional
functionality to allow control over various dedicated Lab.gruppen features within the PLM. It is also possible to use the Lake Controller to
control larger systems configured with PLMs, Dolby Lake Processors and other Dolby Lake legacy devices.
Latency
The small but finite delay incurred by audio signals when they are transformed into the digital domain, processed digitally and then converted
back into analog signals. In the Lake system, latency is assured to be constant.
Legacy Lake
This term refers to older Lake stand-alone audio equipment which may form part of an audio system. The Lake Controller has the capability
to control Lake legacy products.
equipment
LimiterMax LimiterMax is the name given to Lake's proprietary package of dynamics control which forms part of the Lake Processing system.
Line driver An analog audio amplifier, usually with zero gain, having very low output impedance and high drive capability. They are used for transmitting
balanced analog audio over very long cables.
Linear phase See FIR Filters
crossover
LoadLibrary
The Lake Controller software incorporates LoadLibrary, an additional set of Modules specific to the PLM Series. These Modules include a
database of the electrical characteristics of various popular loudspeakers in addition to the standard Module data. The PLM uses the load
data when verifying and monitoring amplifier loads. See Fingerprint, LoadSmart and SpeakerSafe.
Loads, equal/unequal The PLM draws different current levels from the AC supply, and thus has different power ratings, according to whether all channels of the
amplifier are driving into the same load impedance, or if there are different impedances on different channels.
LoadSmart LoadSmart is a load verification procedure within the PLM which allows the operator to confirm that each PLM output has the correct
quantity and type of speaker connected to it. It is intended to be used pre-performance prior to running SpeakerSafe.
Loop-thru
This term refers to the Link connectors provided on the PLM for daisy-chaining further amplifiers or other equipment. The use of these to
connect further devices is termed a loop-thru.
MAC address
In addition to an IP address, every device on an Ethernet network has a MAC address. This address is fixed at the time of manufacture, and
is effectively the permanent identifier of the physical unit. MAC stands for Media Access Control
MaxPeak Dolby Lake's LimiterMax provides independent dynamics control over signal peaks (MaxPeak) and the average signal level (MaxRMS).
MaxRMS See MaxPeak.
Module Module is the term used in the Lake Controller to describe the virtual set of signal processing that routes an audio input to the various
frequency-weighted outputs of a crossover. The processing system within the PLM allows for two Modules, each of which may be
assigned a range of crossover configurations, input sources, etc.
Module Preset
A class of Preset within the Lake processing system. A Module Preset (Module file) contains all the configuration data and settings for one
Module, and is saved in the Lake Controller software, not in the PLM.
Offline
A device on an Ethernet network which is not communicating with the rest of the network either due to a fault or intentionally is said to
be offline.
Online A device on an Ethernet network which is fully operational and communicating with the rest of the network is said to be online.
PAL Short for Power Average Limiter, PAL is proprietary Lab.gruppen circuit which provides additional amplifier protection. The PAL ensures
that the power drawn by the PSU from the AC mains does not exceed the fuse or breaker ratings.
PLM Series Operation Manual rev 1.1.3
11. Appendix
83