Orban OPTIMOD 8400 - CLIPPER CONTROLS

OPTIMOD-FM OPERATION
3-35
AGC Crossover allows you to choose Allpass, LiNoDly, or Linear modes.
Allpass 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 frequency. The two bands
are down 3 dB at the crossover frequency.
All Five-Band factory presets automatically use
Allpass because of its smooth, shelving
behavior and low delay. Its allpass characteristic complements the existing phase rotator
that reduces voice distortion. Because the Five-Band structure uses phase-rotating cross-
overs 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.
LiNoDly (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 fre-
quency response close to the crossover frequency.
LiNoDly is available in Two-Band presets only. It is useful if you need a
crossover 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 dis-
parate.
Linear
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.
Linear was used in all Two-Band and Five-Band presets in v. 1.0 and below, and was the
only available characteristic. It is still 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
Allpass and LiNoDly), so it is
not a good choice if you need to drive talent headphones.
Clipper Controls
Clipper Controls
Intermediate Name Advanced Name Range
--- OSComp Dr –2.0 … +2.0
Bass Clip Thresh BassClpThre –6.0 … 0.00
Bass Clip Mode BassClpMode Soft, Medium, Hard, LLHard
--- Hard Clip Shape 0 … 10
HF Clipping HF Clipping 0 ... 6.0 dB