Orban OPTIMOD-FM 8600Si, Operating Manual

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OPTIMOD-FM DIGITAL OPERATION
3-69
over-control of transient material by the distortion controller. Instead, the final clip-
per is permitted to control some of the transient material (to increase “punch”),
even though, technically, such clipping introduces “distortion.” A setting of 4 to 5
dB works best in most cases. Factory default is 5 dB for virtually all presets.
This control does not affect the HD processing chain.
HF Clip Threshold (available in 8500-style presets only) sets the threshold of the
multiband clipper in band 5 with reference to the final clipper threshold, in dB. This
clipper helps prevent distortion in the final clipper when the input program material
contains excessive energy above 6 kHz.
The Band 5 multiband clipper operates at 256 kHz and is fully anti-
aliased.
This control does not affect the HD processing chain.
B5 Clip Threshold (UL presets only) has the same functionality as
HF C
LIP
THRESHOLD (
above).
B4 Clip Threshold (UL presets only) sets the threshold of the multiband clipper in
band 4 with reference to the final clipper threshold, in dB.
High Frequency Limiter sets the amount of additional gain reduction occurring in
band 5 when high frequency energy would otherwise cause excessive distortion in
the final clipper. It uses an analysis of the activity in the final clipper to make this de-
termination and works in close cooperation with the band-5 multiband clipper.
Functionally, this control is a mix control that adds a HF limiter gain reduction signal
to the band 4 gain reduction signal to determine the total gain reduction in band 5.
Higher settings produce more HF limiting.
This control does not affect the HD processing chain.
MB DownExpStCpl (“Multiband Downward Expander Stereo Coupling”) deter-
mines whether the multiband downward expander stereo coupler is on or off.
B1 / B2 Xover (Band 1 to Band 2 Crossover Frequency) sets the crossover frequency
between bands 1 and 2 to either 100 Hz, 150 Hz, or 200 Hz. It significantly affects
the bass texture, and the best way to understand the differences between the two
crossover frequencies is to listen. The information found in
Getting the Bass Sound
You Want (starting on page 3-86) is also useful.
Band 1-5 MaxDeltGR controls set the maximum permitted gain difference be-
tween the left and right channels for each band in the multiband limiter. The 8600Si
uses a full dual-mono architecture, so the channels can be operated anywhere from
fully coupled to independent. We recommend operating the bands fully coupled
(
B
AND
1-4 M
AX
D
ELT
GR
= 0) for best stereo image stability. However, audio processing
experts may want to experiment with lesser amounts of coupling to achieve a wider,
“fatter” stereo image at the cost of some image instability.
Limiter Attack controls allow you to set the limiter attack anywhere from 0 to
100% of normal in the Five-Band compressor / limiters. Because the limiter and com-
pressor characteristics interact, you will usually get best audible results when you set