In SuperCollider, always plot an unfamiliar UGen before playing it to avoid dangerous amplitude spikes

SuperCollider gives direct low-level access to audio objects (UGens) without any safety clipping or limiting. Certain UGens produce catastrophic amplitude spikes when given out-of-range parameters: the BPF unit with a negative rq value drives amplitude to enormous levels. The primary safety rule is: for any new UGen or unfamiliar parameter, use .plot() before .play to inspect the signal range visually. A secondary hazard: when using MouseX.kr or MouseY.kr with dual monitors, the mouse can venture into negative-coordinate space, sending negative values to UGens that can’t handle them. Always check that the expected value range matches what the UGen can safely accept.

Examples

// DANGEROUS — NEVER PLAY THIS, only plot it:
{ BPF.ar(WhiteNoise.ar(0.4), rq: -1) }.plot(0.05);
// Safe pattern: plot first, play only if range is sane
{ SinOsc.ar(MouseX.kr(0, 1000)) !2 }.plot(0.01);
{ SinOsc.ar(MouseX.kr(0, 1000)) !2 }.play;

Assessment

Explain the dual-monitor problem with MouseX.kr(0, 1000): under what display configuration can the mouse produce values outside [0, 1000]? How would you guard against this in a live performance?