Orban OPTIMOD-FM 8700, Operating Manual

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OPTIMOD-FM DIGITAL OPERATION
3-35
DJ Bass (5-Band only) control determines the amount of bass boost produced on
some male voices. In its default
O
FF
position, it causes the gain reduction of the
lowest frequency band to move quickly to the same gain reduction as its nearest
neighbor when gated. This fights any tendency of the lowest frequency band to de-
velop significantly more gain than its neighbor when processing voice because voice
activates the gate frequently. Each time it does so, it resets the gain of the lowest
frequency band so that the gains of the two bottom bands are equal and the re-
sponse in this frequency range is flat. The result is natural-sounding bass on male
voice.
If you prefer 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.
The difference will never exceed the difference that would have other-
wise occurred if the lowest frequency band were independently gated. If
you are familiar with older Orban processors like the 8200, 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 100 Hz, there will be lit-
tle 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 fun-
damental 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 frequency were a bit high-
er.
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 is a program-adaptive 6 dB/octave shelving equalizer with a 4 kHz turn-
over frequency. It constantly monitors the ratio between high frequency and broad-
band energy and adjusts the amount of equalization in an attempt to make this ra-
tio constant as the program material changes. It can therefore create a bright, pre-
sent sound without over-equalizing material that is already bright.
Rumble Filter 30 Hz HPF determines if a 30 Hz 18 dB/octave highpass filter will be
placed in-circuit before other processing. This control affects both the HD and FM
processing chains regardless of the setting of the
FM

HD C
ONTROL
C
OUPLING
con-
trol.
Phase Rotator determines if the phase rotator will be in-circuit. The purpose of the
phase rotator is to make voice waveforms more symmetrical. This can substantially
reduce distortion when they are peak limited by the 8700i’s back end processing.