Modulating a low filter's cutoff with an envelope while resonance is high adds spectral movement and bite to each bass note

Closing a low-pass filter down and then modulating its cutoff with a per-note envelope makes each note open up spectrally at onset and close as the envelope decays — the classic subtractive ‘wow’ that gives a bass its bite. Turning resonance up emphasises the frequencies around the moving cutoff, so the sweep becomes an audible peak that tracks the envelope. This is distinct from a pitch envelope (which sweeps pitch): here the harmonic content, not the fundamental, is animated. Used together on a techno bass, a pitch envelope supplies the initial thud and the filter envelope supplies the ongoing spectral articulation.

Examples

VCV Rack: close the voice’s filter cutoff to a low value, take resonance all the way up, then open the filter’s envelope-modulation amount so the note’s own envelope sweeps the cutoff. Combine with the bend/pitch envelope for stacked punch.

Assessment

Patch an envelope to a resonant low-pass filter’s cutoff on a bass voice; describe how raising resonance changes the audible effect of the sweep, and how this differs from modulating pitch.