Alesis DEQ230 Reference Manual page 55

3
Basics of Equalization
Multi-band application and results
So far we have only dealt with cutting or boosting single frequency
bands. The differences between the constant Q and variable Q
methods become more "graphic," if you will, when adjacent
frequency bands are involved.
In this example, three adjacent bands are used. They have settings
of + 6 dB, 0 dB, and + 6 dB, respectively:
You can see how the 0 dB setting on the variable Q equalizer
merely serves to round off the top of the curve; in actuality, this
translates into a boost in the range of frequencies under that
band's control. You would have to cut the gain on that band
significantly to reduce the unintended consequences of boosting
the other two frequency ranges.
The constant Q equalizer, on the other hand, has more precise
control over each of the frequency bands. As you can see in this
example, the effect on the center band is significantly lower:
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