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.
Limiter Threshold
Fast Mode Threshold
Transient Threshold
Transient Threshold
Gate Threshold
Output Target
Fast
Time
Transient
Time
ALC Response Time
Transient
Time
ALC
Response
Time
ALC
Response
Time
Freeze
INPUT
OUTPUT
