Lab.gruppen PLM 20000Q - Manual (Page 25)

Signal Flow and Lake Processing
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PLM Series Quick Start and Field Reference Guide Rev 1.3.5
5.4 Loudspeaker Processor Overview
The Lake Processing system within PLM Series devices may be configured with up to two processing
Modules containing a total of up to six processing Module outputs, although the number of power outputs
will be either two or four depending on the PLM model being used. To make use of the extra processing
channels, multiple hardware devices may be connected together using the Super Module feature as sum-
marized in section 5.3.3.
Each set of processing elements is referred to as a Module and can be configured as crossovers, full-
bandwidth auxiliary outputs, or a combination of the two. The relationship between inputs and outputs is
defined via the Lake Controller or via the front panel Input Config Menu.
The Lake Processing system provides two distinct categories of crossovers:
▸ Infinite Impulse Response filters (IIR) such as the classic Bessel, Butterworth or Linkwitz-Riley types;
these are available with slopes ranging from 6 dB/octave to 48 dB/octave.
▸ Finite Impulse Response filters (FIR) providing zero phase shift with steep transition slopes at the
crossover frequencies. These are also referred to as Linear Phase Crossovers.
Further details on crossovers and module types is available in the Lake Controller Operation Manual.
5.5 Files and Presets
The Lake system provides various methods for storing and recalling Module, Frame, or system-wide data.
An overview is provided below; for further information please refer to the Lake Controller Operation Manual.
5.5.1 Module, System and Sub-System Configuration Files
Module, System and Sub-System Configuration files are stored on the Lake Controller PC, and data is
passed across the network when recalling or storing these type of files.
▸ A Module file is the smallest set of data that can be stored and recalled; it contains crossover, gain,
delay, and limiter information for an individual loudspeaker (i.e. the data shown in red in the signal flow
diagrams in section 5.1). A Module file may be recalled into other Lake devices. It is not possible to
store a Module File directly on the hardware device.
▸ A System or Sub-System Configuration File contains a set of Module file information in addition to
Frame related information such Group data and I/O configuration (i.e. the data shown in blue in the
signal flow diagrams in section 5.1).
5.5.2 Frame and System Presets
The entire processor configuration can be stored as a Frame Preset on this hardware device. Presets can
be recalled via the front panel (refer to section 6.10.6) or via the Lake Controller software or Preset Manager
utility; presets can be stored using the Lake Controller software or Preset Manager utility.