A stereo lookahead limiter: push a mix or a track against a ceiling, catch the peaks, and keep the stereo image intact. An Output trim lets you compare the limited sound with the original at a fair level.
The idea
The limiter watches the left and right channels separately but turns both down together. A peak on one side, or a hard-panned or anti-phase peak, lowers the whole signal rather than pulling the image towards the other side. A short lookahead lets it see a transient coming and reduce the gain before it arrives.
The ceiling is checked against an estimate of the peaks between samples, not just the samples themselves, which is what matters once a file is played back or encoded.
Controls
- Gain drives the signal into the limiter. More gain means more density and more reduction.
- Ceiling is the peak level the output should stay under.
- Release sets how quickly the gain recovers after a peak. Short settings sound louder but can make sustained bass gritty.
- Output turns the result down after limiting, without changing how hard it is limited. Use it to match levels and judge the effect by ear rather than by loudness.
The panel shows the actual gain reduction and recent output peaks.
Getting started
Play a mix, a drum loop or any recording through it. Start with Gentle ceiling, then try Mix density, Drum pressure and Heavy handed, and lower Output until the limited and bypassed sound are about as loud as each other.
Honest limits: the ceiling is an estimate, and encoding or later processing can still create higher peaks, so measure the file you deliver with a meter such as Metergram. This is a peak limiter, not a loudness (LUFS) normalizer, and its lookahead adds about 2 ms of latency.
