Clipper Controls - Orban Optimod-FM 8300 Operating Manual

3-33
OPTIMOD-FM DIGITAL OPERATION

Clipper Controls

The clipper controls are common to the Two-Band and Five-Band structures, except
as noted in the control descriptions on the following pages.
All of the clipper controls are common to the Full Modify and Advanced Modify, ex-
cept O , which is only available in the Advanced Modify
C D
VERSHOOT OMPENSATOR RIVE
screen. (Note that "advanced" controls are accessible only from 8300 PC Remote
software.)
Bass Clip ("Bass Clip Threshold") sets the threshold of Orban's patented embedded
bass clipper with reference to the final clipper. The bass clipper is embedded in the
multiband crossover so that any distortion created by clipping is rolled off by part of
the crossover filters. The threshold of this clipper is usually set between 2 dB and 5
dB below the threshold of the final limiter in the processing chain, depending on
the setting of the L control in the parent preset on which you are basing
-M
ESS ORE
your Modify adjustments. This provides headroom for contributions from the other
three bands, so that bass transients don't smash against the back-end clipping sys-
tem, causing overt intermodulation distortion between the bass and higher fre-
quency program material.
Some 8300 users feel that the bass clipper unnecessarily reduces bass punch at its
factory settings. Therefore, we made the threshold of the bass clipper user-
adjustable. The range (with reference to the final clipper threshold) is 0 to –6 dB. As
you raise the threshold of the clipper, you will get more bass but also more distor-
tion and pumping. Be careful when setting this control; do not adjust it casually. Lis-
ten to program material with heavy bass combined with spectrally sparse midrange
material (like a singer accompanied by a bass guitar) and listen for IM distortion in-
duced by the bass' pushing the midrange into the clipping system. In general, unless
you have a very good reason to set the control elsewhere, we recommend leaving it
at the factory settings, which were determined following extensive listening tests
with many types of critical program material.
In the Five-Band structure, the clipper is located after bands 1 and 2 are summed. In
the Two-Band structure, the clipper is located after the Bass band.
Speech Bass Clip set the threshold of the bass clipper when the 8300 detects the
presence of speech. It is usually set to "0" to prevent the bass clipper from adding
distortion on speech.
CLIP SHAPE ("Bass Clip Shape") allows you to change shape of the knee of the in-
put/output gain curve of the bass clipper. The "knee" is the transition between no
clipping and flat topping. A setting of "0" provides the hardest knee. "10" is the
softest knee, where the transition starts 6 dB below B setting and
C T
ASS LIP HRESHOLD
occurs gradually. The factory default setting is "7.6."
FINAL CLIP ("Final Clip Drive") adjusts the level of the audio driving the back end
clipping system that OPTIMOD-FM uses to control fast peaks. This control primarily
determines the loudness / distortion trade-off.