Sweeping a high-resonance (high-Q) filter is the acid-line's whole sonic identity

A resonant filter set to high Q emphasizes the frequency at its cutoff point, creating a vocal or whistling tone at the cutoff. When this cutoff is swept — moved up and down over the sequence — the resonant peak sweeps through the spectrum, creating the distinctive squelch and howl of the 303-style acid bass. This is not just a plain filter-sweep; it is a resonant filter-sweep — the high Q value is what gives the sound its character. Without the resonance the same sweep is merely a brightness change; with it the sweep sings.

Examples

Acid: saw + resonant LPF (Q=15+) + envelope on cutoff + accent. Strudel: .sound(‘sawtooth’).lpf(800).lpq(18).

Assessment

Explain what distinguishes an acid-line from a regular filter sweep. What role does Q/resonance play, and why is it essential to the sound’s identity?