3-30
OPERATION
ORBAN MODEL 8382
The 8382’s multiband clipping and distortion control system works to
help prevent audible distortion in the final clipper. As factory program-
mers, we prefer to adjust the FINAL CLIP
control through a very narrow
range (typically –0.5 dB to –1.0dB) and to determine almost all of the
loudness / distortion trade-off by the setting of the Multiband Clipping
control.
The final clipper operates at 256 kHz sample rate and is fully anti-aliased.
Overshoot Compensator Drive
sets the drive level into the overshoot compensa-
tor with reference to the final clip threshold, in units of dB. The normal setting is
“0dB.”
The overshoot compensator can produce audible distortion on material with strong
high frequency content (like bell trees), and this control lets you trade off this dis-
tortion against loudness. (Such material can cause strong overshoots, forcing the
overshoot compensator to work hard to eliminate them.) We do not recommend
operating this control above “0” because this would reduce the effectiveness of the
distortion cancellation used in earlier processing. However, you can reduce it below
“0” if you value the last bit of high frequency cleanliness over loudness.
The overshoot compensator works at 256 kHz sample rate and is fully anti-aliased.
The Two-Band Structure
The Two-Band structure is an improved version of Orban's classic 8182A OPTIMOD-
TV, but with increased high frequency clarity, substantially lower speech distortion,
and an added AGC (Automatic Gain Control). It consists of a slow two-band gated
AGC for gain riding, followed by an equalization section, a gated two-band com-
pressor, a high-frequency limiter, and a complex distortion-controlled peak limiting
system similar to the one used in the Five-Band structure. A CBS Loudness Controller
can be activated to control subjectively perceived loudness.
Like the “Two-Band Purist” structure in Orban’s OPTIMOD-TV 8282, the 8382’s Two-
Band Structure can be made phase-linear throughout to maximize sonic transpar-
ency. However, you can also choose an allpass crossover structure (see
AGC
C
ROSSOVER
on page 3-28).
The Two-Band structure has an open, easy-to-listen-to sound that is similar to the
source material if the source material is of good quality. However, if the spectral
balance between the bass and high frequency energy of the program material is in-
correct, the Two-Band structure (when its
B
ASS
C
OUPLING
control is operated toward
0%) can gently correct it without introducing obvious coloration.
If you need these automatic re-equalization capabilities of the Two-Band
structure, you may find one of the Five-Band presets to be even more ef-
fective.
There are seven Two-Band presets. These are described following
Table 3-1: Factory
Programming Presets
on page 3-15.
Summary of Contents for Optimod-TV 8382
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