3-36
OPERATION ORBAN Model 8400
Final Clip Drive FinalClpDr –3.0 … +5.0
(Composite) Clip Drive Comp Drive Off, 0 ... 3 dB
Pilot Protect PilotProtect Off, On
Table 3-5: 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 Intermediate Modify and Advanced Modify
screens, except
OSComp Dr, which is only available in the Advanced Modify screen.
Bass Clip Thresh
sets Orban’s patented embedded bass clipper. It 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
Less/More control in the parent preset on which you are basing your Modify adjustments.
This provides headroom for contributions from the other three bands, so that bass tran-
sients don’t smash against the back-end clipping system, causing overt intermodulation
distortion between the bass and higher frequency program material.
Some 8400 users feel that the bass clipper unnecessarily reduces bass punch at its factory
settings. To accommodate these users, the threshold of the bass clipper is 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 distortion and pumping. Be
careful when setting this control; do not adjust it casually. Listen to program material
with heavy bass combined with spectrally sparse midrange material (like a singer accom-
panied by a bass guitar) and listen for IM distortion induced 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 de-
termined 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.
Bass Clip Mode sets the operation of the bass clipper to Hard, LL Hard, Medium, or Soft.
Hard operates the clipper like the clipper in the 8200. It produces the most
harmonic distortion.
This can be useful if you want maximum bass punch, because this setting al-
lows bass transients (like kick drums) to make square waves. The peak level
of the fundamental component of a square wave is 2.1 dB higher than the
peak level of the flat top in the square wave. So this allows you to get low
bass that is actually higher than 100% modulation—the harmonics produced
by the clipping work to hold down the peak level.
The square waves produced by this clipper are filtered through a 6 dB/octave
lowpass filter that is down 3 dB at 400 Hz. This greatly reduces the audibil-
ity of the higher clipper-generated harmonics. Nevertheless, the downside is
To Next Page
Loading...
Need help?
General
