USER MANUAL
48
| HCO-3931
Property
Description
Dynamic
Regulation,
True Peak
Output
Limiter
The
True Peak Output Limiter
limits the output to remain under the selected threshold and is
independent from the ALC and can be activated separately. This prevents loud portions of
programs from being unintentionally clipped.
As a 1ms protection buffer is included, and the output will never go over the limiter threshold
setting.
Enable:
Set to enable this stage of output Compressor processing for this program tab. Deselect
to bypass this stage of ALC processing.
Limiter Threashold:
If any input channel of a program is over this threshold, the limiter will
reduce the entire program very quickly, within 1 millisecond. This limits the output loudness to
always be under this threshold. This is used to avoid loud portions of programs to be
unintentionally clipped.
ALC
Regulation
According to the
Global Configuration
setting in the
Config
tab, these parameters set the
loudness normalization and maximum level of audio signals.
Enable:
Set to enable this stage of ALC processing for this program tab. Deselect to bypass this
stage of ALC processing.
Target Loudness:
Sets the target output loudness. This value sets the average output loudness,
which means that due to the program dynamics, the output loudness will move around the
selected target loudness. The units of measurement and the nominal value, as well as the window
size for the measurements are set by the
Global Configuration
setting in the
Config
tab.
Although the nominal Target Loudness is reset according to the
Global Configuration
setting is
changed, you can change the value at any time using this pulldown, where the available range is -
10 to -31 for all operating modes. See
for 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.
Response Time:
Outside of the
Fast
and
Transient
modes ranges, the ALC performs loudness
correction slowly, following the
Response Time
.
Freeze Threashold:
Sets the threshold below which the ALC will not increase loudness. This
prevents quiet portions of programs (and noise) from being unintentionally boosted. 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.
Fast Mode Response:
This 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, at the rate set in the Speed pull-down (slow = 100ms; fast =
25ms). 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:
This 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).
