Part 85b

Parametric EQ

The same filter from Parts 4–6, reframed as a mixing tool. Boost or cut at specific frequencies with variable bandwidth.

Filters as Tools

In synthesis, filters remove frequencies: you carve a tone out of a harmonically rich oscillator. In mixing, the same math boosts or cuts. A parametric EQ is a filter you can tune precisely: choose a center frequency, decide how much to boost or cut, and set how wide the affected region should be.

Three Bands

A classic three-band parametric EQ uses three filter types. A low shelf boosts or cuts everything below a threshold (think bass control). A peaking filter targets a narrow band in the midrange. A high shelf boosts or cuts everything above a threshold (think treble). Each has three parameters: frequency (where it acts), gain (how much boost or cut in dB), and Q (how wide the affected region is).

Reading the Curve

The frequency response curve shows what the EQ does before you hear it. Flat means no change. A bump means boost; a dip means cut. The width of the bump or dip is controlled by Q. Learning to read this curve is the first step toward intentional mixing.

Try it: start with "Flat" on white noise, then try "Scooped Mids" to hear the classic metal guitar tone. Switch to saw to hear how EQ shapes musical content.

Source
Preset
Low
Mid
High
Frequency Response
Spectrum