TC Electronic DB4 MKII - Manual (Page 16)

MDX 5.1
12 DB4 / DB8 MKII Algorithms
Level, the gain is +3 dB for the Center channel,
but unity (0 dB) for the others. At low level (-
35 dBFS and below), the number after the “D” in
the preset title indicates the amount of low level
boost. For example, the preset “Film Curve D6”
adds 9 dB of low level gain to the Center chan-
nel, but 6 dB of low level gain to the rest of the
channels.
MDX 5.1 algorithm – main page
MDX 5.1 algorithm – main page
Input Gain Normalizer for
Main and LFE channels
Range: -18 dB to +18 dB
As we process in a 48 bit domain both positive
and negative gain normalization can be per-
formed prior to low level processing and output
limiting. These gain controls therefore operate in
a safe location, well protected from generating
output overloads.
Reference Level
Range: -24 dBFS to 0 dBFS in 0.5 dB steps
This parameter sets the reference level in the al-
gorithm. The reference level is the level at which
the Threshold parameters will start operating
when set to 0 dB. E.g. if the Reference Level is
set to -18 dBFS (often referred to as 0 dBu), a
Threshold setting at -4 dB, will cause the Com-
pressor to start operating at -22 dBFS.
Crest
Range:
Peak, 6 dB, 10 dB, 12 dB, 14 dB,
16 dB, 20 dB, 24 dB, RMS
Select compression method between RMS and
PEAK.
The dB steps between RMS and Peak are the
dBs needed for a peak-value to override RMS
measurement.
DXP Defeat Level
Range: Off, -30 dB to -3 dB
MDX 5.1 may remove low level gain below the
threshold set with this parameter to avoid having
irrelevant sources (e.g. background noise) be-
come audible. Low level gain is not revoked if the
DXP Defeat Level parameter is set to Off.
The Defeat threshold is relative to DXP Band
Thresholds, which are relative to Reference Lev-
el.
Example: If Reference Level is set at -20 dBFS,
Band Thresholds at -15 dB, and DXP Defeat
at -22 dB, low level boost starts rolling off at
-47 dBFS. See example at page 18.
Nominal Delay
Range: 0 to 15 ms
0 to 2 ms in 0.1 ms steps
2 ms to 15 ms in 0.5 ms steps
Adds a delay to the passing audio in order to
have regulation start “ahead of time”. Using this
control can reduce the need for peak limiting,
and prevent dynamic distortion from being add-
ed to sensitive material.
Note that look-ahead is scaled with Attack per
band.
Example: If a 5 ms Nominal Delay has been set,
and Attack is 10 ms on the low band and 1 ms
on the high band, audio is delayed 5 ms on all
bands (phase linear topology). However, to pre-
vent pre-transient holes from being generated,
Attack regulation starts 5 ms “ahead of time” on
the low band, but only a little more than 1 ms
“ahead of time” on the high band.
Hi/Lo Crossovers
MDX 5.1 uses a phase linear, 48 bit split and re-
combination filter structure in order to enable dif-
ferent low level detail boost at different frequen-
cies. This counteracts spectral inter-modulation,
and is useful in order to preserve speech intel-
ligibility. Two-band or wide-band DXP process-
ing can be accomplished by setting one or both
crossover points to Off.