Orban OPTIMOD 8685, Руководство по эксплуатации, Страница: 184 / 357

3-40
OPERATION ORBAN MODEL 8685
response in this frequency range is flat. The result is natural-sounding bass on male
voice. This is particularly desirable for most sound-for-picture programming.
If you like a larger-than-life, “chesty” sound on male voice, set this control away
from
O
FF
. When so set, gating causes the gain reduction of the lowest frequency
band to move to the same gain reduction (minus a gain offset equal to the numeri-
cal setting of the control) as its nearest neighbor when gated. You can therefore set
the maximum gain difference between the two low frequency bands, producing
considerable dynamic bass boost on voice. This setting might be appropriate for
news and sports.
The difference will never exceed the difference that would have other-
wise occurred if the lowest frequency band were gated independently. If
you are familiar with older Orban processors like the 8282, this is the
maximum amount of boost that would have occurred if you had set their
DJ B
ASS
B
OOST
controls to O
N
.
The amount of bass boost will be highly dependent on the fundamental
frequency of a given voice. If the fundamental frequency is far above
100Hz, there will be little voice energy in the bottom band and little or
no audio bass boost can occur even if the gain of the bottom band is
higher than the gain of its neighbor. As the fundamental frequency
moves lower, more of this energy leaks into the bottom band, and you
hear more bass boost. If the fundamental frequency is very low (a rarity),
there will be enough energy in the bottom band to force significant gain
reduction, and you will hear less bass boost than if the fundamental fre-
quency were a bit higher.
This control is only available in the Five-Band structure.
If the G
ATE
T
HRESH
(Gate Threshold) control is turned O
FF
, the DJ B
ASS
boost setting is disabled.
HF Enhance (“High Frequency Enhancer”) is a program-adaptive 6 dB/octave shelv-
ing equalizer with a 4 kHz turnover frequency. It constantly monitors the ratio be-
tween high frequency and broadband energy and adjusts the amount of equaliza-
tion in an attempt to make this ratio constant as the program material changes. It
can therefore create a bright, present sound without over-equalizing material that is
already bright. Used gently, it is useful for improving dialog intelligibility, particu-
larly with the two-band structure because, unlike the five-band structure, the two-
band structure cannot automatically re-equalize high frequencies.
Highpass Filter determines if a sweepable 18 dB/octave highpass filter will be
placed in-circuit before other processing. This filter is useful for reducing low fre-
quency noise, particularly when the 8685 is being used for production or mastering.
This filter is available only in the 2.0 processing chain.
Lowpass Filter control sets the bandwidth (and therefore the amount of high fre-
quency signal the 8685 passes) from 10 kHz to 20 kHz. The lowpass filter can replace
any anti-aliasing filters in downstream equipment. Set the filter to 20 kHz (full
bandwidth) for downstream equipment with sample rates of 44.1 or 48 kHz. Set the
filter to 15 kHz for 32 kHz sample rate. For other sample rates, set the filter so that
it is as close as possible to 45% of the sample rate without exceeding 45%.