Optimod-AM 9400 V1.2 Operating Manual - Orban

OPTIMOD-AM DIGITAL OPERATION 3-45
grammers made the trade-offs between the settings of the various distortiondetermining
controls at various levels of processing.
The 9400’s multiband clipping and distortion control system works to
help prevent audible distortion in the final clipper. As factory programmers,
we prefer to adjust the FINAL CLIP control through a narrow range
(typically –0.5 dB to –2.0dB) and to determine almost all of the loudness /
distortion trade-off by the setting of the MULTIBAND LIMIT DRIVE and
MULTIBAND LIMIT THRESHOLD controls.
The final clipper operates at 256 kHz sample rate and is fully anti-aliased.
Overshoot Comp Drive sets the drive into the overshoot compensator with reference
to the final clip threshold, in units of dB. The normal setting is “0 dB.”
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 distortion 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.
Multiband Dynamics Processing
The AGC, and Stereo Enhancer controls are common to both the analog AM and
digital radio processing chains. Beyond the AGC, the processing chain splits into two
separate chains, each of which has its own equalizer section, five-band compressor,
Multiband Controls and Distortion Controls
Full Name Advanced Name Range
MB DRIVE Multiband Drive 0 ... 25
MB REL Multiband Release Slow, Slow2, Med, Med2,
MFast, MFast2, Fast
MB GATE Multiband Gate Threshold Off, –44 ... –15 dB
MB LIM DR Multiband Limiter Drive –4.0 ... +5.0 dB
DWNEXP THR Downward Expander Off, –6.0 … 12.0 dB
--- B1/B2 XOVER 100 Hz, 200 Hz
MB LIM THR Multiband Limit Threshold –3.0 +6.0, Off
--- Maximum Distortion Control 0 … 18 dB
--- High Frequency Limiter Off, –23.8 ... 0.0 dB
LESS-MORE LESS-MORE Index [read-only]; 1.0 … 10.0
PARENT PRESET Parent Preset [read-only]
--- B1/B2 XOVER 100 Hz, 200 Hz
AGC METR --- Master, Delta
Table 3-7: Multiband and Distortion Controls