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OPERATION ORBAN MODEL 8500
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.
To produce more limiting, edit this preset by advancing the L
ESS-MORE control (in
Basic Modify). Then save the resulting preset as a user preset. The L
ESS-MORE control
affects only the input drive and you can use it to set a nominal limiting level differ-
ent from 0 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 pre-
sets).
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,
which makes 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-
poses, inaudible to the listener. Low-level passages are increased in level by up to 10
dB, while the dynamics of crescendos are maintained.
The CLASSICAL-2
BAND preset is a two-band preset with the AGC turned off. It uses
considerable bass coupling to preserve the spectral balance of the input as well as
possible. Its L
ESS-MORE control primarily affects the amount of compression, not the
maximum loudness. It sounds essentially identical to the P
ROTECTION-0DB preset ex-
cept that it produces more gain reduction.
CLASSICAL-2B+AGC
uses the AGC set for 2:1 compression ratio. Because of the
AGC, this preset affects more of the total dynamic range of the recording that does
the CLASSICAL-2
BAND preset. However, the AGC provides extremely smooth and
unobtrusive compression because of the gentle ratio and window gating. In this pre-
set, the Two-Band compressor is used very lightly with a fast release time as a peak
limiter. The AGC does almost all of the compression.
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