DelayL creates a one-shot delay; CombL adds feedback to produce echoes with controllable decay time

The SuperCollider delay UGen family (DelayN, DelayL, DelayC; CombN, CombL, CombC) is named with N=non-interpolating, L=linear-interpolating, C=cubic-interpolating. Interpolation matters only if the delay time changes while running — use L or C for modulated delays, N for fixed times. DelayL is a simple delay line: input → output with maxdelaytime and delaytime arguments. CombL adds a feedback path, making the output feed back into the delay; it adds a decaytime argument (the time in seconds for the echo to decay by 60 dB). Multiple CombL in parallel creates pseudo-reverb. XFade2 blends dry and wet signals.

Examples

delay = DelayL.ar(sig, 0.5, 0.3); — 0.3s single delay. comb = CombL.ar(sig, 0.5, 0.3, 3.0); — 0.3s delay, 3s 60dB decay time.

Assessment

A student wants a delay effect where the echoes slowly fade over 4 seconds. Should they use DelayL or CombL? Write the correct UGen call with a maximum delay time of 1 second, delay of 0.4 seconds, and 4-second decay.