3-32
OPERATION
ORBAN MODEL 8300
M
AXIMUM
D
ELTA
G
AIN
R
EDUCTION
control to 3.0 and the
AGC
M
ASTER
D
ELTA
T
HRESHOLD
control to some positive number, depending on how much automatic width control
you want the 8300 to perform.
AGC Bass Delta Threshold
works the same as
AGC
M
ASTER
D
ELTA
T
HRESHOLD
, but
applies to the bass band. You will usually set it the same as
AGC
M
ASTER
D
ELTA
T
HRESHOLD
.
AGC Crossover
allows you to choose
A
LLPASS
,
L
INEAR
N
O
D
ELAY
, or
L
INEAR
modes.
A
LLPASS
is a phase-rotating crossover like the one used in the 8200’s two-band AGC.
It introduces one pole of phase rotation at 200 Hz. The overall frequency response
remains smooth as the two bands take different degrees of gain reduction — the
response is a smooth shelf without extra peaks or dips around the crossover fre-
quency. The two bands are down 3 dB at the crossover frequency.
All Five-Band factory presets automatically use
A
LLPASS
because of its smooth, shelv-
ing behavior and low delay. Its allpass characteristic complements the existing phase
rotator that reduces voice distortion. Because the Five-Band structure uses phase-
rotating crossovers in the five-band compressor / limiter, there is little or nothing to
be gained by using a phase-linear crossover in the Five-Band structure’s AGC.
L
INEAR
N
O
D
ELAY
(Linear-Phase; no delay)
is a phase-linear crossover whose upper
band is derived by subtracting its lower band from the crossover’s input. When the
upper and lower bands have the same gain, their sum is perfectly flat with no phase
rotation. However, when the upper and lower bands have different gains, peaks and
dips appear in the frequency response close to the crossover frequency.
L
INEAR
N
O
D
ELAY
is available in Two-Band presets only. It is useful if you need a cross-
over with low delay and no phase distortion when flat. Its downside is the possibility
of coloration when the gains of the two bands are widely disparate.
L
INEAR
is a phase-linear crossover whose upper band is derived by subtracting its
lower band from the crossover’s input, as passed through a delay equal to the group
delay of the lowpass crossover filter. The overall frequency response remains smooth
as the two bands take different degrees of gain reduction — the response is a
smooth shelf without extra peaks or dips around the crossover frequency. The two
bands are each down 6 dB at the crossover frequency. This crossover has constant
delay even when the two bands have unequal gains.
L
INEAR
is available for Two-Band presets only. While it has the ideal combination of
no phase distortion (even when non-flat) and smooth shelving behavior, it adds
about 4 ms to the overall delay (compared to
A
LLPASS
and
L
INEAR
N
O
D
ELAY
), so it is
not a good choice if you need to drive talent headphones.
Summary of Contents for 8300J
Page 1: ...Operating Manual OPTIMOD FM 8300 Digital Audio Processor Version 2 1 Software...
Page 7: ...Operating Manual OPTIMOD FM 8300 Digital Audio Processor Version 2 1 Software...
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Page 247: ...OPTIMOD FM DIGITAL TECHNICAL DATA 6 29...
Page 254: ...6 36 TECHNICAL DATA ORBAN MODEL 8300 CPU Module...
Page 260: ...6 42 TECHNICAL DATA ORBAN MODEL 8300 8300 RS232 BOARD PARTS LOCATOR...
Page 262: ...6 44 TECHNICAL DATA ORBAN MODEL 8300 8300 POWER SUPPLY PARTS LOCATOR...
Page 264: ...6 46 TECHNICAL DATA ORBAN MODEL 8300 8300 I O BOARD PARTS LOCATOR...
Page 270: ...6 52 TECHNICAL DATA ORBAN MODEL 8300 DSP BOARD PARTS LOCATOR DRAWING 32170 000 14...
Page 278: ...6 60 TECHNICAL DATA ORBAN MODEL 8300 8300 DISPLAY BOARD PARTS LOCATOR...
Page 279: ...OPTIMOD FM DIGITAL TECHNICAL DATA 6 61 DISPLAY BOARD...