Orban OPTIMOD 8685, Руководство по эксплуатации

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OPTIMOD SURROUND PROCESSOR OPERATION
3-75
namics processing, recall the
L
OOK
-A
HEAD
L
IMITER
preset. See page 3-26 for
a description of these presets.
C) If you have started with one of the
S
OFT
K
NEE
presets, the AGC will already be
O
FF
. If you need a very large amount of compression for an application like
processing material intended for in-flight entertainment systems, you can ei-
ther edit the preset to turn the AGC on or start with a preset other than
S
OFT
K
NEE
.
You can turn the AGC off globally for all presets, which is convenient if
you don’t expect to use it in the future. (See step 2 on page 2-20.)
D) Unless you will be using a large amount of compression for special applica-
tions, set the
MB G
ATE
T
HRESHOLD
to O
FF
.
In the S
OFT
K
NEE
and L
OOK
-A
HEAD
L
IMITER
presets, this is already done.
The multiband gate only works appropriately when the K
NEE
and R
ATIO
controls of all bands are set identically, which is typically true in broad-
cast applications. We recommend turning off the multiband gate if the
individual
K
NEE
and
R
ATIO
settings are unequal.
E) Adjust the
2
B
D
RIVE
control (two-band) or
M
B
D
RIVE
control (five-band) to
achieve the desired amount of multiband gain reduction.
F) Adjust the release time control (
2B R
ELEASE
or
MB R
ELEASE
) to achieve the de-
sired compression density.
If you are using the Five-Band structure, you can use the D
ELTA
R
ELEASE
controls to fine-tune the release time of each band independently.
The release characteristic is always “automatic” (i.e., with program-
dependent time constants) and the
R
ELEASE
control simply scales this
process. This, combined with multiband operation, makes the compres-
sion remarkably resistant to the usual compressor pumping and squash-
ing.
G) Adjust the A
TTACK
T
IME
controls on the individual compressors to trade off
overshoot control against transient punch.
H) Adjust the R
ATIO
and K
NEE
controls in each band to taste.
The R
ATIO
control sets the compression ratio at the threshold of compres-
sion. To achieve a classic soft knee characteristic, set the R
ATIO
to 1:1 and
adjust the softness of the knee with the K
NEE
control.
The
K
NEE
control’s setting is the gain reduction in dB at which the com-
pression ratio reaches
∞
:1. (See page 3-53 for a description of the
R
ATIO
,
K
NEE
, and
B
REAKPOINT
controls.)
I) After you adjust the
R
ATIO
and
K
NEE
controls, adjust the
T
HRESHOLD
controls in
the individual bands to achieve the desired amount of gain reduction.
The
K
NEE
control automatically and invisibly changes a given band’s in-
ternal compression threshold to keep the compressor’s output level con-
stant whenever the drive level is high enough to move the gain reduc-
tion into the
∞
:1 range. This means that the internal threshold decreases
with softer knee settings (higher settings of the K
NEE
control). However,
the indicated threshold the 8685’s user interface does not change. This
behavior ensures that the
T
HRESHOLD
control alone determines the maxi-