Wavefolding

Wavefolding is a waveshaping technique that reflects a signal back on itself once it passes a threshold, multiplying harmonics without changing the fundamental.

Each fold maps over-range amplitude back toward zero, turning a smooth input into an increasingly angular, buzzy shape rich in upper partials. In wavetable design it is often applied progressively across frames so the table sweeps from clean to aggressive — at the cost of aliasing risk that usually calls for band-limiting or oversampling.