Instruction manual

GUIDE TO INSTALLATION AND OPERATION
HCO-1822 | 21
Here’s the time-domain response of the ALC:
ALC Pre-Amp Level
A pre-amp stage is available in front of the ALC to compensate for programs having an input loudness out of the ALC
tracking range (very low or very high input loudness). The pre-amp level ranges from -20 dB to + 20 dB, in steps of 1
dB.
Fast Mode Response
The Fast Mode Response is optional and is enabled by checking the Enable box.
The ALC Fast Mode Response kicks in whenever the input loudness goes over the Fast Mode Threshold and
loudness is reduced, in a few milliseconds. The Fast Mode Threshold is given in dB with respect to the target
loudness and ranges from 2 to 12 dB, in dB steps.
Transient Mode Response
The Transient Mode Response is optional and is enabled by checking the Enable box.
The ALC Transient Mode Response kicks in whenever the input loudness goes over or under the Transient Mode
Threshold. The Transient Mode Threshold is symmetric with respect to the target loudness and ranges from 2 to 12
dB, in dB steps. When the input loudness is over the Transient Mode Threshold , loudness is reduced following the
rate set by the Speed
pull-down. When the input loudness is under the Transient Mode Threshold, loudness is
increased, again following the Speed pull-down, which ranges from Slow (up to 15 seconds) to Fast (up to 4
seconds).
Response Time
Outside of the Fast and Transient modes ranges, the ALC performs loudness correction slowly, following the
Response Time. Response time values are : 5 sec, 10 sec, 15 sec, 20 sec, 30 sec, 45 sec, 1 min, 5 min, 10 min, 15
min, 20 min.
Gate Threshold
The Gate Threshold sets the threshold under which the ALC will stop to increase loudness. This avoids quiet
portions of programs (and noise) to be boosted unintentionally. If the input program loudness is under the Gate
Threshold for more than 30 seconds, the ALC will smoothly return to 0 dB of loudness correction.
Limiter Threshold
The Limiter Threshold will limit the output loudness under the selected threshold. This avoids loud portions of
programs to be clipped unintentionally. If the input program loudness is over the Limiter Threshold, the ALC will
reduce the loudness very quickly, in 1 millisecond.