Lookahead
Definition
A feature in limiters and compressors that allows the processor to "look ahead" in the audio signal by a few milliseconds before applying gain reduction. This enables the processor to respond to transients before they actually arrive, preventing overshoot without introducing audible distortion.
In Simple Terms
A feature that lets a limiter peek a few milliseconds into the future so it can catch sudden loud spikes before they happen. It makes the limiting smoother and more transparent — you hear less of the limiter working.
In Practice
A limiter with 1–2 ms of lookahead on the mastering chain catches sharp transients before they hit the ceiling, resulting in more transparent limiting than a zero-lookahead limiter at the same settings.
Common Confusion
Lookahead introduces an equivalent amount of latency — a 2 ms lookahead delays the output by 2 ms. This is irrelevant for mastering but matters in real-time monitoring contexts.