Graphic Equalizer
Purpose
A Graphic Equalizer can provide up to 12dB of boost or cut for each frequency band. The center frequency of each band is fixed at standard ISO frequencies. The bandwidth of each filter is fixed and depends on the number of bands in the equalizer. Graphic Equalizers are available in one octave, 2/3 octave, and 1/3 octave sizes. In a digital system, a Graphic Equalizer is, in most applications, less efficient than a Parametric Equalizer. Each band of a Graphic Equalizer uses approximately the same DSP resources as single Parametric Equalizer band. It is suggested that Parametric Equalizers be used when possible. The main advantage of a Graphic Equalizer over a bank of Parametrics is in its ease of setup and use.
Controls
Band Bypass
Bypasses a single equalizer band. Engaging this button has the same effect as setting the corresponding Band Level control to +0dB.
Band Level
Adjusts the amount of boost or cut provided by the frequency band.
Note: It is possible to create an overload condition within the equalizer if any Band Level is set above +0dB. Such an overload will be indicated by the Overload Indicator.
Device Bypass
Bypasses the equalizer filter section.
Overload
Indicates clipping within the equalizer. Such an overload is possible if any Band Level control is set above +0dB.
Graphical Frequency Response
Displays the frequency response of the filter. See the EQ Curve Graphics Display documentation for a complete description.
Graphic Equalizer Schematic
Schematic for hypothetical 2 band Graphic Equalizer.