A typical layout for semi-pro mixers provides low- and high-shelving equalization from a pair of knobs labeled “bass” and “treble” and one semi-parametric midrange band. The low and high EQ are called shelving because a graph of their response curve looks somewhat like a drawing of a shelf. Any portion of the tone above (in the case of treble EQ) or below (in the case of bass EQ) a factory-preset is boosted or attenuated.
