50 front panel interface – Lab.gruppen PLM 20000Q User Manual
Page 56
50
Front Panel Interface
PLM Series Operation Manual rev 1.2.3
7.11.2.4 Amp Gain
MENU > MODULE > AMP GAIN
By default, all outputs are selected; use the rotary encoder to change the gain of all power outputs or press
the associated output button to deselect one or more outputs.
Amp Gain adjusts the gain of the PLM’s power output stage for each output channel. The default setting is
35 dB, 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.
7.11.2.5 Limiters
MENU > MODULE > LIMITERS
Various parameters of the PLM’s Inter-Sample Voltage Peak Limiter (ISVPL) and the Lake LimiterMax pa-
rameters can be adjusted via this submenu. By default, simultaneous adjustment of most limiter parameters
across all output channels is selected, although channels may be adjusted individually if required. Attack and
Release times must be adjusted individually per channel.
Inter-Sample Voltage Peak Limiter Threshold (ISVPL Threshold)
The ISVPL prevents the voltage of the PLM outputs from exceeding a pre-determined value. The ISVPL
Threshold can be adjusted between 17.8 V to 600 V, which represents the instantaneous peak voltage,
not the RMS value of the output signal. The actual value is displayed in brackets and can be limited by the
maximum voltage a particular PLM Series model can produce.
Inter-Sample Voltage Peak Limiter Profile (ISVPL Profile)
Selecting the ISVPL Profile will optimize the ISVPL limiting for the specific frequency band. ISVPL Profile
permits individual adjustments per channel between six profiles, providing appropriate attack and release
times for the ISVPL Limiter and Voltage Clip feedback to either minimize distortion or maximize SPL as
described below.
1. Universal – Optimized for low distortion, usable for all frequencies
2. Sub/LF – Optimized for higher SPL below 600 Hz, usable for all frequencies
3. Sub – Optimized for high SPL, 20-200 Hz
4. LF – Optimized for high SPL, 20-1200 Hz
5. MF – Optimized for high SPL, 300-6000 Hz
6. HF – Optimized for high SPL, > 1 kHz