Orban OPTIMOD-FM 8500S Operating Manual page 212

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OPERATION
gated by the silence gate.
The release time can be adjusted from 0.5 dB / second (slow) to 20 dB / second (fast).
Settings toward 20 dB / second result in a more consistently loud output, while set-
tings toward 0.5 dB / second allow a wider variation of dynamic range. Both the set-
ting of the 2B R
ELEASE
determine the actual release time of the compressor.
The action of the 2B R
ability. However, its setting is critical to sound quality—listen carefully as you adjust
it. There is a point beyond which increasing density (with faster settings of the 2B
R control) will no longer yield more loudness and will simply degrade the
ELEASE
punch and definition of the sound.
When the 2B R
ELEASE
tings), the amount of gain reduction is surprisingly non-critical. Gating prevents
noise from being brought up during short pauses and pumping does not occur at
high levels of gain reduction. Therefore, the primary danger of using large amounts
of gain reduction is that the level of quiet passages in input material with wide dy-
namic range may eventually be increased unnaturally. Accordingly, when you oper-
ate the 2B R control between 8 and 2 dB / second, it may be wise to defeat
ELEASE
the gain-riding AGC and to permit the two-band compressor to perform all of the
gain riding. This will prevent excessive reduction of dynamic range and will produce
the most natural sound achievable from the Two-Band structures.
With faster 2B R
ELEASE
substantially with the amount of gain reduction in the two-band compressor. This
means that you should activate the gain-riding AGC to ensure that the two-band
compressor is always being driven at the level that produces the desired amount of
gain reduction. Decide based on listening tests how much gain reduction gives you
the density that you prefer while not creating a feeling of over-compression and fa-
tigue.
Release in the two-band compressor automatically becomes faster as
more gain reduction is applied (up to about 10 dB). This makes the pro-
gram progressively denser, creating a sense of increasing loudness al-
though peaks are not actually increasing. If the gain-riding AGC is de-
feated (with the AGC on/off control), you can use this characteristic to
preserve some feeling of dynamic range. Once 10 dB of gain reduction is
exceeded, full loudness is achieved—no further increase in short-term
density occurs as more gain reduction is applied. This avoids the unnatu-
ral, fatiguing sound often produced by processors at high gain reduction
levels and makes OPTIMOD-FM remarkably resistant to operator gain-
riding errors.
2B Gate Thresh (Threshold) control determines the lowest input level that
OPTIMOD-FM recognizes as program; lower levels are considered to be noise or
background sounds and will cause the AGC or two-band compressor to gate, effec-
tively freezing gain to prevent noise breathing.
There are two independent gating circuits in the 8500S. The first affects the AGC
and the second affects the two-band compressor. Each has its own threshold control.
control and the dynamics and level of the program material
control has been optimized for resolution and adjust-
ELEASE
control is set between 8 and 1 dB / second (the slowest set-
control settings (above 8 dB / second), the sound will change
ORBAN MODEL 8500S