Orban OPTIMOD-FM 8600Si, Operating Manual

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OPERATION ORBAN MODEL 8600Si
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
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
I
N
O
D
LY
), so it is not a good
choice if you need to drive talent headphones.
Peak Limiter Controls
There are two sets of peak limiter controls, one of which is active when an 8500-
style preset is active and the other of which is active when an “MX” preset (which
uses the 8600Si’s new peak limiter technology) is active. For a given limiter algorithm
(8500-style or “MX”), the peak limiter controls are common to the Two-Band and
Five-Band structures, except as noted in the control descriptions on the following
pages. In the Five-Band structure, the peak limiter is located after bands 1 and 2 are
summed. In the Two-Band structure, the peak limiter is located after the Bass band.
Peak Limiter Controls Common to 8500-style and MX Presets
Except for
C
OMP
M
ODE
and
M
ULTIPLEX
O
FFSET
, which are only available in the Ad-
vanced Modify, all of the peak limiter controls common to 8500-style and MX Presets
appear in both the Intermediate Modify and Advanced Modify screens.
Composite Limit Mode determines if the composite limiter will operate as a hard
clipper or as Orban’s patented “Half-Cosine Interpolation” composite limiter (which
is not a clipper).
When operating as a hard clipper, the composite limiter will produce
maximum brightness in the frequency range from 5 to 15 kHz because,
unlike the 8600Si’s left/right audio-domain peak limiters, it can produce
square waves in this frequency range. The downside compared to Half-
Cosine mode is that it can noticeably compromise stereo imaging.
When operating in Half-Cosine mode, the composite limiter produces
somewhat less brightness but does not compromise stereo imaging.
In either mode, the baseband output is overshoot compensated and
Peak limiter Controls Common to 8500-Style and MX Presets
PC Remote Name Range
Comp Drive Off, 0 ... 3 dB
PilotProtect Off, On
Multiplex Offset 0 … –10 dB
Comp Mode –3.0 … +5.0
Table 3-5: Peak Limiter Controls Common to 8500-Style and MX Presets