Orban OPTIMOD-FM 5500 Operation Manual page 174

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OPERATION
Obviously, the correct setting will be different for a sporting event than for classical
music. It may be wise to define several presets with different settings of the MB
control and to recall the preset that complements the program ma-
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terial of the moment.
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
control's setting is critical to removing hiss while minimizing re-
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moval of desired program energy.
Starting in V1.1, the Downward Expander's dynamic frequency response is no longer
constrained to being strictly lowpass—Band 5 is now uncoupled from the lower
bands, so the band 5 downward expander can produce less gain reduction than
other bands. This can help prevent loss of desired high frequency material in the
program.
B3>B4 CPL ("Band 3>4 Coupling") control determines the extent to which the gains
of bands 4 (centered at 3.7 kHz) and 5 (above 6.2 kHz) are determined by and fol-
lows the gain of band 3 (centered at 1 kHz). Set towards 100% (fully coupled) this
control reduces the amount of dynamic upper midrange boost, preventing unnatu-
ral upper midrange boost in light pop and instrumental formats. The gain of band 5
is further affected by the B4>B5 CPL control.
B4>B5 CPL ("Band 4>5 Coupling") controls 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 B4>B5 CPL
B4>B5 CPL control receives the independent left and right band 4 gain
control signals; this feed is unaffected by the band 4 M
trol. Range is 0 to 100% coupling.
B3>B2 CPL and B2>B3 CPL 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.
B2>B1 CPL control determines the extent to which the gain of band 1 (below 100Hz
or 200Hz, depending on crossover setting) is determined by and follows the gain of
band 2 (centered at 400Hz). Set towards 100% (fully coupled) it reduces the amount
of dynamic bass boost, preventing unnatural bass boost in light pop and talk for-
mats. Set towards 0% (independent), it permits frequencies below 100Hz (the
"slam" region) to have maximum impact in modern rock, urban, dance, rap, and
other music where bass punch is crucial. The default setting is 30%.
determines the gain reduction in band 5. The
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