Orban OPTIMOD 6200, Руководство по эксплуатации

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OPTIMOD OPERATION
3-25
Settings toward 100% (wideband) make the output sound most like the input. Because
setting the
BASS CPL
control at 100% will sometimes cause bass loss, the most accurate
frequency balance will often be obtained with this control between 70% and 90%. The
optimal setting depends on the amount of gain reduction applied. Adjust the
BASS CPL
control until the band 1 and band 2 Gain Reduction meters track as closely as possible.
With the 2B REL (Two-Band Release) control set to 2dB/second, setting the
BASS CPL
control toward 0% (independent) will produce a sound that is very open, natural, and
non-fatiguing, even with large amounts of gain reduction. Such settings will provide a
bass boost on some program material that lacks bass.
With fast release times, settings of the BASS CPL toward 100% (wideband) do not sound
good. Instead, set the
BASS CPL
control toward 0% (independent). This combination of
fast release and independent operation of the bands provides the maximum loudness and
density on small radios achievable by the Two-Band structure. But such processing may
fatigue listeners with high-quality receivers, and also requires you to activate the AGC to
control the average drive level into the two-band compressor, preventing uncontrolled
build-up of program density. Instead of operating the Two-Band structure like this, you
should almost always choose a Multi-Band preset instead.
BASS CLIP threshold controls Orban’s patented embedded bass clipper. It is embedded
in the multi-band crossover so that harmonics created by clipping are rolled off by part
of the crossover filters. The threshold of this clipper is ordinarily set between 4dB and
6dB below the threshold of the final limiter in the processing chain, depending on the
setting of the
LESS-MORE
control in the parent preset upon which you are basing your
FULL CONTROL adjustments. This provides headroom for contributions from the other
four bands, so that bass transients don’t smash against the look-ahead limiter, causing
overt intermodulation distortion between the bass and higher frequency program mate-
rial.
Some 6200 users feel that the bass clipper unnecessarily reduces bass punch at its factory
settings. To accommodate these users, the threshold of the bass clipper is user-
adjustable. The range (with reference to the look-ahead limiter threshold) is 0 to –6dB.
As you raise the threshold of the clipper you will get more bass but also more distortion
and pumping. Be careful when setting this control; do not adjust it casually. Listen to
program material with heavy bass combined with spectrally sparse midrange material
(like a singer) and listen for IM distortion induced by the bass’ pushing the midrange
into the look-ahead limiter. In general, unless you have a very good reason to set the
control elsewhere, we recommend leaving it at the factory settings, which were deter-
mined as a result of extensive listening tests with many types of critical program mate-
rial.
FINAL LIMT (Final Limit) adjusts the level of the audio driving the look-ahead limiter
that OPTIMOD-DAB uses to control fast peaks, and then adjusts the peak-to-average
ratio. The loudness/distortion trade-off is primarily determined by the
FINAL LIMT
con-
trol.
Turning up the FINAL LIMT control drives the look-ahead limiter harder, reducing the
peak-to-average ratio, and increasing the loudness on the air. When the amount of limit-