Named because it was designed to equalize the response
of the room. The goal was to use the notches and peaks of the equalizer to
compensate for resonances and
dead spots within a room
Types
Graphic
Fixed center frequency, fixed Q, variable amplitude
Spaced in octaves (or fraction of octaves, 1/2 octave or
1/3 octave)
Parametric
Variable center frequency, variable Q, variable
amplitude
Typically only 3 or 4 bands
Semi-Parametric
Variable center frequency, fixed Q, variable amplitude