Clipper Controls - Orban OPTIMOD-FM 5500 Operation Manual

OPTIMOD-FM DIGITAL

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
C
VERSHOOT
screen. (Note that "advanced" controls are accessible only from 5500 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
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 5500 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 5500 detects the
presence of speech. It is usually set to "0" to prevent the bass clipper from adding
Clipper Controls
Full Modify Name
---
BASS CLIP
FINAL CLIP
COMP DRV
, which is only available in the Advanced Modify
D
OMPENSATOR RIVE
control in the parent preset on which you are basing
-M
ESS ORE
Advanced Name
Overshoot Compensator
Drive
Bass Clip Threshold
Bass Clip Shape
Final Clip Drive
Composite Limiter Drive
Speech Bass Clip
Table 3-5: Clipper Controls
Range
–2.0 ... +2.0
–6.0 ... 0.00
0 ... 10
–3.0 ... +5.0
Off, 0 ... 3 dB
–6.0 ... 0.00
3-33
OPERATION