The 2-Band Structure - Orban OPTIMOD 6300 Operating Manual

OPTIMOD 6300 DIGITAL
spectrally sparse midrange material (like a singer) and listen for IM distortion in-
duced by the bass' pushing the midrange into the look-ahead limiter. Although the
low-IM technology in the 6300's look-ahead limiter substantially reduces this distor-
tion, overdriving the limiter hard enough can still cause problems.
In the 5-band structure, band 1 drives the clipper. In the 2-band structure, the Bass
band drives the clipper.
Bass Clip Shape allows you to change the knee of the input/output gain curve of
the bass clipper. It allows you to control the shape of the "knee"—the transition be-
tween no clipping and flat topping. "0" provides the hardest knee, where the tran-
sition between linear operation and flat topping occurs abruptly as the clipper's in-
put level is changed. "10" is the softest knee, where the transition starts 6 dB below
B C T
ASS LIP HRESH
Final Limit Drive controls (AGC and MB) adjust the level of the audio driving the
low-IM look-ahead limiters that OPTIMOD-PC uses to control fast peaks, thereby ad-
justing the peak-to-average ratio of the processed audio. The F
trols primarily determine the loudness/distortion trade-off.
Turning up the F
ing the peak-to-average ratio, and increasing loudness. When the amount of limit-
ing is increased, the audible intermodulation distortion caused by limiting increases,
even though special algorithms minimize the increase compared to less sophisticated
designs. Lower settings reduce loudness, of course, but result in a cleaner sound.
When you use OPTIMOD-PC in a preemphasized mode (step 8 on page 2-23 and step
9 on page 2-23), this inserts a frequency-dependent high frequency boost before the
look-ahead limiter. This boost can be as large as 20 dB at 20 kHz. When using pre-
emphasis, you must turn down the F
ahead limiter from causing audible gain pumping.
You may find it illuminating to recall several Factory Presets, adjust L
M
ORE
to examine the trade-offs between the release time and F
made by the factory programmers. However, note that all Factory Presets
were created to complement F
must turn down the F

The 2-band Structure

The 2-band structure consists of a stereo enhancer, a slow 2-band gated AGC for
gain riding, an equalization section, a gated 2-band compressor, and a low-IM look-
ahead limiter. A CBS Loudness Controller, which is primarily useful for sound-for-
picture applications, can be activated to control subjectively perceived loudness.
The 6300's 2-band Structure can be made phase-linear throughout to maximize sonic
transparency. However, you can also choose an allpass crossover structure (see AGC
C
on page 3-45).
ROSSOVER
setting and occurs gradually. The factory default setting is "7.6."
L D
INAL IMIT RIVE control drives the look-ahead limiter harder, reduc-
to several points in its range, and then open the Full Control screen
L
INAL IMIT
L D
INAL IMIT RIVE control to prevent the look-
preemphasis. As explained above, you
LAT
D
control when using preemphasis.
RIVE
OPERATION
L D
INAL IMIT RIVE con-
-
ESS
L
drive
INAL IMIT
3-47