lpf() applies a low-pass filter; lower cutoff values muffle sound, higher values let high frequencies through

In Strudel, .lpf(value) applies a low-pass filter at the given cutoff frequency in Hz. Frequencies above the cutoff are attenuated. A value around 200 produces a heavily muffled, bass-heavy sound; around 5000 it passes almost everything, sounding bright. The lpf value can be patterned: .lpf("200 1000 200 1000") alternates filter states across steps without changing the rhythm. This separates timbral modulation from rhythmic structure — a key live coding technique.

Examples

sound(“bd sd”).lpf(500) // muffled sound(“hh*4”).lpf(“200 1000 200 1000”) // alternating filter

Assessment

Describe the sonic difference between .lpf(200) and .lpf(5000) on a hi-hat pattern. Then write a pattern where the filter opens and closes rhythmically.