6. Signal Flow and Lake® Processing
PLM+ SERIES Operation Manual rev
3.0.1
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6.5. Loudspeaker Processor Overview
The Lake Processing system within PLM+ Series devices may be configured with up to four processing Modules
containing a total of up to twelve processing Module outputs, that can be routed to any of the four power output
channels.
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.
6.6. 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.
6.6.1. 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 (see Figure 6.1).
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 (see Figure 6.1).
6.6.2. 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 7.11.7) or via the Lake Controller software or Preset Manager utility;
presets can be stored using the Lake Controller software or Preset Manager utility.
A maximum of 100 Frame Presets can be stored on this device. The data within a Frame Preset includes the
configurations of all Modules in the Frame, including levels, crossover, EQ, input mixer, routing, and all other
parameters. As Frame Presets are stored in the hardware device, recall is available without using a PC.
Using the System Presets function in the Lake Controller, entire system configurations can be stored and recalled
across a network of LM, PLM and PLM+ Series devices. This enables fast retrieval and switching of entire system
configurations as minimal data is being sent between the Controller and Processors.
