OPTIMOD-FM DIGITAL
OPERATION
3-45
ance between the bass and high frequency energy of the program material is incor-
rect, the Two-Band structure (when its
BAND
COUPLING
2>1
control is operated to-
ward 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 the AGC is defeated.
PROTECTION
0DB
sets the limiting threshold so that limiting almost never occurs,
while
PROTECTION
5DB
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
0DB
if you want limiting
to occur only when the program level
exceeds
the maximum normal input level as
determined by a PPM or VU meter monitoring the input program line. Recall preset
PROTECTION
5DB
if you want about 5 dB of limiting to occur at the maximum nor-
mal input level.
The
L
ESS
-M
ORE
control affects only the input drive, and you can use it to set a nomi-
nal 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
.
These are the only two-band presets (other than the
PROTECTION
presets).
Classical music is traditionally broadcast with a wide dynamic range. However, with
many recordings and live performances, the dynamic range is so great that the quiet
passages disappear into the noise on most car, portable, and table radios. Conse-
quently, the listener either hears nothing, or must turn up the volume control to
hear all the music. Then, when the music gets loud, the radio blasts and distorts,
making listening unpleasant.
The Two-Band structure is well suited for classical formats during daytime hours
when most people in the audience are likely to be listening in autos or to be using
the station for background music. This audience is best served when the dynamic
range of the program material is reduced by 10-15 dB so that quiet passages in the
music never fade into inaudibility under these less-favorable listening conditions.
OPTIMOD-FM controls the level of the music in ways that are, for all practical pur-
Summary of Contents for OPTIMOD-FM 8500S
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