OPTIMOD-AM DIGITAL
OPERATION
3-25
AGC
R
ELEASE
control to fast settings sounds different from the increase in density
caused by setting the multiband compressor’s
M
ULTIBAND
R
ELEASE
control to
F
AST
,
and you can trade the two off to produce different effects.
Unless it is purposely speeded-up (with the
AGC
R
ELEASE
control), the automatic
gain control (AGC) that occurs in the AGC prior to the multiband compressor makes
audio levels more consistent without significantly altering texture. Then the multi-
band compression and associated multiband clipper audibly change the density of
the sound and dynamically re-equalize it as necessary (booming bass is tightened;
weak, thin bass is brought up; highs are always present and consistent in level).
The various combinations of AGC and compression offer great flexibility:
Light AGC + light compression yields a wide sense of dynamics, with a small
amount of automatic re-equalization.
Moderate AGC + light compression produces an open, natural quality with au-
tomatic re-equalization and increased consistency of frequency balance.
Moderate AGC + moderate compression gives a more dense sound, particularly
as the release time of the multiband compressor is sped up.
Moderate AGC + heavy compression (particularly with a
FAST
multiband release
time) results in a “wall of sound” effect, which may cause listener fatigue.
Adjust the AGC (with the
AGC
D
RIVE
control) to produce the desired amount of
AGC action, and then fine-tune the compression and clipping with the 9300 pro-
cessing’s controls.
AGC GATE
(“AGC Gate Threshold”) control determines the lowest input level that
will be recognized as program by OPTIMOD-AM; lower levels are considered to be
noise or background sounds and cause the AGC or multiband compressor to gate,
effectively freezing gain to prevent noise breathing.
There are two independent gating circuits in the 9300. The first affects the AGC and
the second affects the multiband compressor. Each gate has its own threshold con-
trol.
The multiband compressor gate causes the gain reduction in bands 2 and 3 of the
multiband compressor to move quickly to the average gain reduction occurring in
those bands when the gate first turns on. This prevents obvious midrange coloration
under gated conditions, because bands 2 and 3 have the same gain.
The gate also independently freezes the gain of the two highest frequency bands
(forcing the gain of the highest frequency band to be identical to its lower neigh-
bor), and independently sets the gain of the lowest frequency band according to the
setting of the
DJ
B
ASS
boost control (in the Equalization screen). Thus, without in-
troducing obvious coloration, the gating smoothly preserves the average overall
frequency response “tilt” of the multiband compressor, broadly maintaining the
“automatic equalization” curve it generates for a given piece of program material.
Summary of Contents for OPTIMOD-AM 9300
Page 1: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 7: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 178: ...3 46 OPERATION ORBAN MODEL 9300...
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Page 221: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 21...
Page 222: ...6 22 TECHNICAL DATA ORBAN MODEL 9300 CONTROL BOARD PARTS LOCATOR...
Page 228: ...6 28 TECHNICAL DATA ORBAN MODEL 9300...
Page 229: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 29 I O DSP BOARD LEFT AND RIGHT ANALOG INPUTS...
Page 230: ...6 30 TECHNICAL DATA ORBAN MODEL 9300 I O DSP BOARD ANALOG OUTPUTS...
Page 231: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 31...
Page 238: ...6 38 TECHNICAL DATA ORBAN MODEL 9300 FRONT VIEW REAR VIEW FRONT PANEL PARTS LOCATOR DIAGRAM...
