Orban OPTIMOD-FM 8700, Operating Manual

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OPERATION ORBAN MODEL 8700i
Note also that it is virtually impossible to achieve undetectable dynamic noise reduc-
tion of program material that is extremely noisy to begin with, because the program
never masks the noise. It is probably wiser to defeat the dynamic noise reduction
with this sort of material (traffic reports from helicopters and the like) to avoid ob-
jectionable side effects. You must let your ears guide you.
Band 5 is particularly critical for noise reduction because much of the Downward Ex-
pander’s utility lies in hiss reduction. Hiss has most of its energy in band 5, while
program material typically has less energy in this band, so the
B5 D
OWN
E
XPANDER
D
ELTA
T
HRESHOLD
control’s setting is critical to removing hiss while minimizing re-
moval of desired program energy.
The Downward Expander’s dynamic frequency response is not constrained to being
strictly lowpass—Band 5 is uncoupled from the lower bands, so the band 5 down-
ward expander can produce less gain reduction than other bands. This can help pre-
vent loss of desired high frequency material in the program.
Band 3 > 4 Coupling control determines the extent to which the gain of band 4 and
5 (centered at 3.7 kHz) is determined by and follows the gain of band 3 (centered at
1 kHz). Set towards 100% (fully coupled) it reduces the amount of dynamic upper
midrange boost, preventing unnatural upper midrange boost in light pop and in-
strumental formats.
Band 4 > 5 Coupling control the extent to which the gain of band 5 (6.2 kHz and
above) is determined by and follows the gain of band 4.
The sum of the high frequency limiter control signal and the output of
the
B
AND
4 > 5 C
PL
control determines the gain reduction in band 5. The
B
AND
4 > 5 C
PL
control receives the independent left and right band 4
gain control signals; this feed is unaffected by the band 4
M
AX
D
ELTA
G/R
control. Range is 0 to 100% coupling.
Band 3 > 2 Coupling and Band 2 > 3 Coupling controls determine the extent to which
the gains of bands 2 and 3 track each other.
When combined with the other coupling controls, these controls can ad-
just the multiband processing to be anything from fully independent op-
eration to quasi-wideband processing.
Band 2 > 1 Coupling control determines the extent to which the gain of band 1 (be-
low 100 Hz) is determined by and follows the gain of band 2 (centered at 400 Hz).
Set towards 100% (fully coupled) it reduces the amount of dynamic bass boost, pre-
venting unnatural bass boost in light pop and talk formats. Set towards 0% (inde-
pendent), it permits frequencies below 100 Hz (the “slam” region) to have maximum
impact in modern rock, urban, dance, rap, and other music where bass punch is cru-
cial. The default setting is 30%.
MB Band Mix controls determine the relative balance of the bands in the multiband
compressor. Because these controls mix
after the band compressors, they do not af-
fect the compressors’ gain reductions and can be used as a graphic equalizer to fine-
tune the spectral balance of the program material over a

6 dB range.