Phase Reverse; Amp Gain; Limiters - Lab.gruppen PLM series Operation Manual

9. Front Panel Interface
This allows the Module gain to be adjusted at two different places. Soft function buttons 2 and 3 select
Module A or Module B inputs respectively for gain adjustment. Soft function buttons 5-8 select Module
outputs 1-4 for gain adjustment. Gain may be adjusted in 0.1 dB increments from -100 dB to +20 dB, which
is the default gain setting unless another range has been specified in the Module settings. The Module gain
parameters may also be adjusted from the Lake Controller software.
The Group Sum value is also displayed (in brackets) for this parameter for each channel.
9.13.2.2 Delay
This option is selected by pressing soft button 3 (Delay) from Menu è Module.
The audio signal may be delayed (typically for reasons of driver or delay subsystem alignment) at either the
PLM Module inputs or on individual outputs. Delay added at the inputs will, of course, affect all outputs
equally, and will be generally be introduced to time-align arrays of loudspeakers at different locations.
Delaying individual outputs may be desirable to time-align drivers in the same cabinet or array.
Delay is adjustable in increments of 0.1 ms. Maximum input delay is 1.8 s, and maximum output delay is
100 ms which is the default delay setting unless another range has been specified in the Module settings.
The Module delay parameters may also be adjusted from the Lake Controller Software.
The Group Sum value is also displayed (in brackets) for this parameter for each channel.

9.13.2.3 Phase reverse

This option is selected by pressing soft button 4 (Polarity) from Menu è Module.
Audio phase reversal is available at the inputs to Module A and Module B, and also individually on the four
output channels. The on-screen text displays "Positive" for normal operation, and "Negative" when a
signal is phase inverted. The input or output may be selected with the adjacent soft button and the polarity
changed with the rotary encoder. The Module phase reverse settings may also be adjusted from the Lake
Controller software.

9.13.2.4 Amp Gain

This option is selected by pressing soft button 5 (Amp Gain) from Menu è Module.
This adjusts the gain of the PLM's power output stage for each output channel. The default gain setting is
35 dB, but this is variable in 0.1 dB increments from 22 dB to 44 dB. Care should be taken in altering Amp
Gain, which should be adjusted in conjunction with the Gain controls and limiter thresholds (see section
9.12.2.1).

9.13.2.5 Limiters

This option is selected by pressing soft button 6 (Limiters) from Menu è Module.
Various parameters of the PLM's Inter-Sample Voltage Peak Limiter (ISVPL) and the Lake Processing
system's LimiterMax can be adjusted in this submenu. By default, simultaneous adjustment of most limiter
parameters in all four output channels is selected, though channels may be adjusted individually if desired.
Attack and Release times must be adjusted individually per channel.
57
PLM Series Operation Manual rev 1.1.3