Lab.gruppen PLM 20K44 - Manual (Page 72)

9. Appendix
72
PLM+ SERIES Operation Manual rev 1.0.0
9.5. Glossary of Terms, Acronyms and Abbreviations
The explanations given in Table 9.4 below are based on the specific use of each term in this manual. The
definitions are not intended to be exhaustive and many of these terms have wider meanings.
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 that 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 LM 26, PLM, PLM+ or legacy 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 hardware device, and each holds the complete
configuration of all Modules and the Modules’ internal settings.
Gigabit Ethernet
Describes the speed of Ethernet data transfer for devices that transmit Ethernet frames at a rate of a gigabit per second, as defined by the
IEEE 802.3-2008 standard.
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.
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 mains
breakers. The PLM+’s PSU contains circuitry to control the in-rush current to prevent this.
Input Level
The amplitude of an audio signal at the point where it is applied to the input of the device, 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)
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 Lake Processors and a Lake Controller they are assigned and
detected automatically.
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
ISVPL is an abbreviation for Inter-Sample Voltage Peak Limiter, a proprietary Lab.gruppen technique for ensuring that voltage at the output terminals of a PLM+
does not exceed a pre-determined level. Eight ISVPL profiles provide the ability to configure for low distortion or high SPL specific to certain frequency ranges,
or for universal use.
Lake Controller
The Lake Controller is the software application used to control LM 26 Processors, PLM+ Series and other Lake devices. This software application provides
additional functionality and allows various grouping functions for simultaneous control of multiple Lake Processing enabled 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 Device
This term refers to older Lake audio equipment which may form part of an audio system (i.e. Lake Contour Pro 26, Lake Mesa Quad EQ and the Dolby Lake
Processor). The Lake Controller has the capability to control all Lake legacy products.
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 Crossover See FIR Filters.
Load Library
The Lake Controller includes LoadLibrary, a set of Module files 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.
Load, 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 Lake’s LimiterMax provides independent dynamics control over signal peaks (MaxPeak) and the average signal level (MaxRMS).
Module
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 device 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 hardware device.