OPTIMOD-AM DIGITAL
OPERATION
3-45
grammers made the trade-offs between the settings of the various distortion-
determining 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 program-
mers, 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
M
ULTIBAND
L
IMIT
D
RIVE
and
M
ULTIBAND 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 refer-
ence 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
Summary of Contents for Optimod-AM 9400
Page 1: ...Operating Manual OPTIMOD AM 9400 Digital Audio Processor Version 1 2 Software...
Page 7: ...Operating Manual OPTIMOD AM 9400 Digital Audio Processor Version 1 2 Software...
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Page 261: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 29...
Page 267: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 35 CPU Module...
Page 273: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 41 RS232 BOARD PARTS LOCATOR...
Page 275: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 43 8300 POWER SUPPLY PARTS LOCATOR...
Page 284: ...6 52 TECHNICAL DATA ORBAN MODEL 9400 DSP BOARD PARTS LOCATOR DRAWING 32170 000 14...
Page 292: ...6 60 TECHNICAL DATA ORBAN MODEL 9400 DISPLAY BOARD PARTS LOCATOR...
Page 293: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 61 DISPLAY BOARD...