Orban OPTIMOD-FM 8600Si, Operating Manual

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OPTIMOD-FM DIGITAL OPERATION
3-33
mize the maximum error,” or “equal-ripple”) IIR digital approximation to the curves
provided by the Orban 622B analog parametric equalizer. Therefore, unlike less so-
phisticated digital equalizers that use the “bilinear transformation” to generate EQ
curves, the shapes of the 8600Si’s curves are not distorted at high frequencies.
Midrange Parametric Equalizer is a parametric equalizer whose boost and cut
curves closely emulate those of an analog parametric equalizer with conventional
bell-shaped curves.
MID FREQ determines the center frequency of the equalization, in Hertz.
Range is 250-6000Hz.
MID GAIN determines the amount of peak boost or cut (in dB) over a
±
10 dB range.
MID WIDTH determines the bandwidth of the equalization, in octaves.
The range is 0.8-4.0 octaves. If you are unfamiliar with using a parametric
equalizer, 1 octave is a good starting point.
The audible effect of the midrange equalizer is closely associated with the amount
of gain reduction in the midrange bands. With small amounts of gain reduction, it
boosts power in the presence region. This can increase the loudness of such material
substantially. As you increase the gain reduction in the midrange bands (by turning
the
M
ULTIBAND
D
RIVE
(Multiband Drive) control up), the
M
ID
G
AIN
control will have pro-
gressively less audible effect. The compressor for the midrange bands will tend to
reduce the effect of the Mid frequency boost (in an attempt to keep the gain con-
stant) to prevent excessive stridency in program material that already has a great
deal of presence power. Therefore, with large amounts of gain reduction, the den-
sity of presence region energy will be increased more than will the level of energy in
that region. Because the 3.7 kHz band compressor is partially coupled to the gain
reduction in the 6.2 kHz band in most presets, tuning
M
ID
F
REQ
to 2-4 kHz and turn-
ing up the
M
ID
G
AIN
control will decrease energy in the 6.2 kHz band — you will be
increasing the gain reduction in both the 3.7 kHz and 6.2 kHz bands. You may wish
to compensate for this effect by turning up the
B
RILLIANCE
control.
Use the mid frequency equalizer with caution. Excessive presence boost tends to be
audibly strident and fatiguing. Moreover, the sound quality, although loud, can be
very irritating. We suggest a maximum of 3 dB boost, although 10 dB is achievable.
In some of our factory presets, we use 3 dB boost at 2.6 kHz to bring vocals more up-
front.
High Frequency Parametric Equalizer is a parametric equalizer whose boost and
cut curves closely emulate those of an analog parametric equalizer with conven-
tional bell-shaped curves.
HIGH FREQ determines the center frequency of the equalization, in
Hertz. The range is 1-15 kHz
HIGH GAIN determines the amount of peak boost or cut over a
±
10 dB
range.
HIGH WIDTH determines the bandwidth of the equalization, in octaves.
The range is 0.8-4.0 octaves. If you are unfamiliar with using a parametric