Peak Limiter Controls - Orban OPTIMOD-FM 8500S Operating Manual

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OPERATION

Peak Limiter Controls

All Five-Band factory presets automatically use A
smooth, shelving behavior and low delay. Its allpass characteristic com-
plements the existing phase rotator that reduces voice distortion. Be-
cause 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.
(Linear-Phase; no delay) is a phase-linear crossover whose upper band is de-
L N D
I O LY
rived 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 ap-
pear in the frequency response close to the crossover frequency.
is useful if you need a crossover with low delay and no phase
L N D
I O LY
distortion when flat. Its downside is the possibility of coloration when
the gains of the two bands are widely disparate.
L is a phase-linear crossover whose upper band is derived by subtracting its
INEAR
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.
While L
INEAR
when non-flat) and smooth shelving behavior, it adds about 4 ms to the
overall delay (compared to A
choice if you need to drive talent headphones.
The clipper controls are common to the Two-Band and Five-Band structures, except
as noted in the control descriptions on the following pages.
Bass Clip Mode sets the operation of the bass clipper to H
.
S
OFT
•
operates the clipper like the clipper in the 8200. It produces the most har-
H
ARD
Clipper Controls
Full Modify Name
---
BASS CLIP
FINAL CLIP
COMP DRV
MPX LIMIT MODE
has the ideal combination of no phase distortion (even
and L
LLPASS
Advanced Name
Overshoot Compensator
Drive
Bass Clip Threshold
Bass Clip Shape
Final Clip Drive
Composite Limiter Drive
Speech Bass Clip
MPX Limiter Mode
Table 3-5: Clipper Controls
ORBAN MODEL 8500S
because of its
LLPASS
), so it is not a good
N D
I O LY
, LL H , M
ARD ARD
Range
–2.0 ... +2.0
–6.0 ... 0.00
0 ... 10
–3.0 ... +5.0
Off, 0 ... 3 dB
–6.0 ... 0.00
Hard, HalfCos
, or
EDIUM