An equalizer you can plug in: its state, a panel that draws it with a handle on each band and an engine that plays it, side by side. Play pink noise and the spectrum behind the curve is what comes out

A filter you can plug in: its state, a panel that draws the curve it plays with a handle for the cutoff and the resonance, and an engine that plays it. Play a loop through it and drag, the spectrum behind is what comes out

A channel EQ you can plug in: its state, a panel that draws the curve with a handle on the mid band and an engine that plays it. Play a loop through it and drag, the spectrum behind is what comes out