Orban OPTIMOD-FM 8600Si, Operating Manual

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OPERATION ORBAN MODEL 8600Si
Most equalization controls are common to both the Two-Band and Five-Band struc-
tures. The equalizer is located between the AGC and multiband compressor sections
of both structures.
Any equalization that you set will be automatically stored in any User Preset that
you create and save. For example, you can use a User Preset to combine an unmodi-
fied Factory Programming Preset with your custom equalization. Of course, you can
also modify the Factory Preset (with Basic Modify, Full Modify, or Advanced Modify)
before you create your User Preset.
In general, you should be conservative when equalizing modern, well-recorded pro-
gram material.
Except for
B
ASS
G
AIN
, most of the factory presets use less than 3 dB of equalization.
Bass Shelf Controls , the Five-Band
structure’s low bass equalization
controls are designed to add punch
and slam to rock and urban music.
They provide a parametric shelving
equalizer with control over gain,
hinge frequency, and slope (in
dB/octave).
BASS FREQ sets the frequency
where shelving starts to take effect.
BASS GAIN sets the amount of bass boost ( dB) at the top of the shelf.
BASS SLOPE sets the slope ( dB/octave) of the transition between the
top and bottom of the shelf.
Because the Five-Band structure often increases the brightness of program material,
some bass boost is usually desirable to keep the sound spectrally well balanced. Ad-
justment of bass equalization must be determined by individual taste and by the re-
quirements of your format. Be sure to listen on a wide variety of radios — it is possi-
ble to create severe distortion on poor quality speakers by over-equalizing the bass.
Be careful!
The moderate-slope (12 dB/octave) shelving boost achieves a bass boost that is more
audible on smaller radios, but which can sound boomier on high-quality receivers.
The steep-slope (18 dB/octave) shelving boost creates a solid, punchy bass from the
better consumer radios with decent bass response. The 6 dB/octave shelving boost is
like a conventional tone control and creates the most mid-bass boost, yielding a
“warmer” sound. Because it affects the mid-bass frequency range, where the ear is
more sensitive than it is to very low bass, the 6 dB/octave slope can create more ap-
parent bass level at the cost of bass “punch.”
There are no easy choices here; you must choose the characteristic you want by iden-
tifying your target audience and the receivers they are most likely to be using. Re-
gardless of which curve you use, we recommend a +2 to +5 dB boost for most for-
mats. Larger amounts of boost will increase the gain reduction in the lowest band of
the multiband compressor, which may have the effect of reducing some frequencies.
Hz
55 110 220 440
0 dB
+3 dB
+6 dB
Bass Gain
Bass Shelf Hinge Frequency
6dB/oct
12dB/oct
18dB/oct
Bass Slope