Orban OPTIMOD 8400 - THE TWO-BAND STRUCTURE

OPTIMOD-FM OPERATION
3-41
(See Bass Clip Mode on page 3-36.)
The Two-Band Structure
The Two-Band structure consists of a slow two-band gated AGC (Automatic Gain Con-
trol) for gain riding, followed by an equalization section, a gated two-band compressor, a
high-frequency limiter, and a complex peak limiting system similar to the one used in the
Five-Band structure. Like the “Two-Band Purist” structure in Orban’s OPTIMOD-FM
8200, the 8400’s Two-Band Structure is phase-linear throughout to maximize sonic
transparency.
The Two-Band structure has an open, easy-to-listen-to sound that is similar to the source
material if the source material is of good quality. However, if the spectral balance be-
tween the bass and high frequency energy of the program material is incorrect, the Two-
Band structure (when its
Band Coupling 2>1 control is operated toward 0%) can gently
correct it without introducing obvious coloration.
The Two-Band structure is mainly useful for classical or “fine arts” programming that
demands high fidelity to the original program source.
The Protection Presets
There are two Protection Factory Presets. Both use the same DSP code as the Two-Band
Purist structure, but with the AGC defeated.
PROTECTION 0 dB sets the limiting threshold so that limiting almost never occurs, while
PROTECTION 5 dB sets the limiting threshold so that program material at the maximum
normal input level (as determined by a PPM or VU meter monitoring the input program
line) produces an average limiting of 5 dB.
To set up the Protection Limiter, recall preset
PROTECTION 0 dB if you want limiting to
occur only when the program level exceeds the maximum normal input level as deter-
mined by a PPM or VU meter monitoring the input program line. Recall preset
PROTECTION 5 dB if you want about 5 dB of limiting to occur at the maximum normal
input level.
The
Less/More control affects only the input drive, and you can use it to set a nominal
limiting level different from 0 dB or 5 dB.
The Protection presets have the same Intermediate and Advanced Modify
controls available as the Two-Band structure.
Setting Up the Two-Band Structure for Classical Music
To set up the Two-Band structure, recall preset CLASSICAL-2 BAND or CLASSICAL-
2B+AGC
.