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OPERATION ORBAN Model 8400
Range is 20-500 Hz.
Low Gain
determines the amount of peak boost or cut (in dB) over a ±10 dB
range.
Low 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 equal-
izer, 1.5 octaves is a good starting point. These curves are relatively broad be-
cause they are designed to provide overall tonal coloration, rather than to notch
out small areas of the spectrum.
The LF parametric can be used in the mid-bass region (100-300 Hz) to add
“warmth” and “mellowness” to the sound when boosting. When cutting, it
can remove a “woody” or “boxy” sound. In our presets, we tend to use it
very sparingly (in the order of 1 dB boost) to add a bit of extra bass warmth.
One formula for producing a very “big” bass sound on the air is to use a
peaking boost at 100 Hz in combination with a Bass Shelf boost at 6
dB/octave.
The equalizer, like the classic Orban analog parametrics such as the 622B,
has constant “Q” curves. This means that the cut curves are narrower than
the boost curves. The width (in octaves) is calibrated with reference to 10 dB
boost. As you decrease the amount of EQ gain (or start to cut), the width in
octaves will decrease. However, the “Q” will stay constant.
“Q” is a mathematical parameter that relates to how fast ringing damps out.
(Technically, we are referring to the “Q” of the poles of the equalizer trans-
fer function, which does not change as you adjust the amount of boost or
cut.)
The curves in the 8400’s equalizer were created by a so-called “minimax”
(Minimize the Maximum error, or “equal-ripple”) IIR digital approximation
to the curves provided by the Orban 622B analog parametric equalizer.
Therefore, unlike less sophisticated digital equalizers that use the “bilinear
transformation” to generate EQ curves, the shapes of the 8400’s curves ac-
curately emulate an analog equalizer, even 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 Frequency
determines the center frequency of the equalization, in Hertz.
Range is 250-6000 Hz.
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 equal-
izer, 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 loud-
ness of such material substantially. As you increase the gain reduction in the
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