TC Electronic DB4 MKII - Manual (Page 70)

ALC 5.1
66 DB4 / DB8 MKII Algorithms
and Limit Threshold is a quality defining factor. If
the difference is too small, wide dynamic range
material may be hampered. See Limit Threshold
details in the next section and Fig 6, 9, 10 and 11.
In broadcast environments working against a
fixed dialnorm value, Target Level should typi-
cally be set 2 to 4 dB higher than the permanent
Dialnorm value. This will ensure the best listen-
ing result if a consumer engages reproduction
processing.
Stereo Offset
While the BS.1770 measurement works for stereo
as well as for 5.1 signals, a different Target Level
may be better in some distribution scenarios:
When end-listener down-mix is relied on, hav-
ing the same Target Level for stereo and for 5.1
can create systematic level-jumps at consumers
listening to stereo. Therefore, ALC5.1 includes a
novel automatic discrimination function, allowing
for slightly different Target Levels to apply when
the signal is strereo compared to when it’s 5.1.
The Stereo Offset parameter allows a smooth
and automatic Target Level change when the in-
put is stereo. For instance, if Target Level is set to
-21 LFS and Stereo offset is set to -3 LU, ALC5.1
uses a Target Level of -21 LFS for 5.1 programs,
but a Target Level of -24 LFS for stereo.
Max Reduction
Sets the maximum number of dBs the processor
is allowed to attenuate the signal. If this param-
eter is set to 0.0 dB, level reduction is disabled
regardless of other settings such as Correction.
Max Boost
Sets the maximum number of dBs the processor
is allowed to boost the signal. If this parameter is
set to 0.0 dB, level boost is disabled regardless
of other settings such as Correction.
Correction
Sets how much correction is applied when the
actual loudness is different from the Target Lev-
el. 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
value, especially if you wish to cover within pro-
gram level jumps and inter-program level jumps
using one preset. See Fig 6.
Freeze Level
Sets the level below which a Gain Boost is grad-
ually revoked. Use Freeze to avoid boosting sig-
nals meant to remain below the noise floor of
a certain broadcast platform. Freeze relates to
Target Level. 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. See Fig 7, pa-
rameter no 3.
Freeze Hold
Sets the time in seconds before the processor
resets to 0 dB gain change, when the level falls
below Freeze Level.
See Fig 7, parameter no 4.
Fig 6
The Correction parameter.
With a setting of 30 %, program which is 10 dB
off target will be corrected by 3 dB.