Manual

ALC2
Loudness Pilot English Manual (2014-10-07) 93
Correction parameter
Use the Correction parameter to set how much
correction is applied when the actual loudness
is different from the Target Level. For instance, if
Correction is set at 40%, and loudness is 6dB
away from the Target Level, the processor will
apply a correction of 2.4dB.
Be careful when setting this parameter, as it may
take a little “time testing” to arrive at the best val-
ue, especially if you wish to cover within program
level jumps and inter-program level jumps using
one preset. Note that Stridency Reduction over-
rides the Corrections parameter when the input
level is higher than Target.
Stridency Reduct. parameter
Stridency Reduction is an adaptive loudness
control that only has effect for loud signal above
Target Level.
As consumers, once we have adjusted the gain
for a suitable sound pressure level, we are more
tolerant of loudness dropping than of loudness
going up – see “Loudness Descriptors to Char-
acterize Wide Loudness-Range Material” from
the 127th AES conference, 2009.
Use the Stridency Reduct. parameter to deter-
mine how programs are dealt with. This param-
eter is influenced by the Pre Process parameter.
The Stridency Reduct. parameter is limited by
the setting of the Max Reduction parameter on
this page. Available settings are „Off“, „Soft“,
„Universal“ and „Extra“. When set to anything
but “Off”, Stridency Reduction overrides the
general Correction setting for loud content.
Slow Window parameter
The „slow window“ is an area around the set Tar-
get Level. Within the slow window, loudness is
controlled only gently. When the signal exceeds
the limits of the slow window, Loudness is treat-
ed more radically. Use the Slow Window param-
eter to define the size of this window.
Use the Slow Window parameter in combination
with the Avg. Rate parameter. E.g., a setting of
10dB means that the slow window is a range of
±5 dB around the current setting of the Target
parameter.
Freeze Level parameter
Use the Freeze Level parameter to set a level
below which a Gain Boost is gradually revoked.
This parameter can be used to avoid boosting
signals meant to remain below the noise floor of
a certain broadcast platform. The Freeze Level
parameter relates to the Target Level parameter
on the ALC page. For instance, if Target Level is
set at -21LFS, and Freeze Level is set at -15dB,
positive gain (if enabled) will be gradually nulled
when level falls below -36LFS.
Freeze Hold parameter
Use the Freeze Hold parameter to set the time
(in seconds) before the processor resets to 0dB
gain change once the level falls below Freeze
Level.
Pre Process parameter
Use the Pre Process parameter to indicate the
condition of the input program – i.e., if it has al-
ready been normalized to Target level or not.
As procedures in production and on the servers
moves towards programs already having been
normalized prior to transmission, the amount of
processing should gradually be backed off.
Avoid quality-hampering “sausage processing”
by setting this parameter to indicate the cor-
rect state of the input signal. The Pre Process
parameter is included with Presets, so it may
consequently be altered based on GPI or SNMP
commands.