Stereo Enhancer Controls - Orban OPTIMOD-FM 8500S Operating Manual

OPTIMOD-FM DIGITAL
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 funda-
mental 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 higher.
This control is only available in the Five-Band structure.
If the G
boost setting is disabled.
HF ENH ("High Frequency Enhancer") is a program-adaptive 6 dB/octave shelving
equalizer with a 4 kHz turnover frequency. It constantly monitors the ratio between
high frequency and broadband energy and adjusts the amount of equalization in an
attempt to make this ratio constant as the program material changes. It can there-
fore create a bright, present sound without over-equalizing material that is already
bright.
30HZ HPF ("30 Hz High Pass Filter") determines if a 30Hz 18 dB/octave highpass fil-
ter is placed in-circuit before other processing. Although not a stereo enhancer con-
trol, it is found on the stereo enhancer page (for convenience) because, like the ste-
reo enhancer, it can be adjusted without eliminating L
PH-ROTATE ("Phase Rotator") is not a stereo enhancer control. It 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 8500S's back end processing.
In most cases, we recommend that the phase rotator be left active. However, be-
cause it can slightly reduce the clarity and definition of program material, you can
defeat it if you are operating the 8500S conservatively and not attempting to
achieve very high on-air loudness.
You have somewhat more leeway than you do in older Orban FM processors like the
8200 because the 8500S's new distortion control will work to help prevent audible
speech distortion even when the phase rotator is switched out.

Stereo Enhancer Controls

The stereo enhancer is common to the FM and HD processing chains. You can oper-
ate it in one of two modes or "styles." The first emulates the Orban 222 analog ste-
reo enhancer, while the second mode, called Delay, emulates a popular enhancer
from another manufacturer that adds a delayed version of the L–R signal to the
original L–R to create stereo enhancement. (See Stereo Enhancement on page 3-8
for more information.)
Both modes have gating that operates under two conditions.
(Gate Threshold) control is turned O
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ATE HRESH
, the DJ B
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-M functionality.
ESS ORE
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