MusicReasonProduction, Synthesis, and Audio Math
What release time matches this pulse?
Declare a tempo, a rhythmic division to pump to, and a release multiplier. This tool computes a starting release-time value in milliseconds. It never claims that timing alone yields a correct sidechain effect, since the actual result also depends on your compressor's threshold, ratio, and the source material's own envelope.
Answer
Want to learn more? Musical Time in Delay, Reverb, and Modulation
Understand
A common sidechain-compression goal is to have the "ducked" element recover to full volume right as the next rhythmic pulse arrives, so the release time is often set close to the target division's own duration at the current tempo. A multiplier below 1.0 recovers early, leaving a small gap before the next pulse; a multiplier above 1.0 has not fully recovered by the time the next pulse lands.
Worked examples
At 120 BPM targeting a quarter note with a 1.0 multiplier, the release time is exactly 500 ms, the same as the quarter note's own duration at that tempo. Doubling the tempo to 240 BPM, with everything else unchanged,exactly halves the result to 250 ms, since the note's own duration halves along with the tempo.
Method and limitations
The release time is the target division's own duration at the stated tempo, using the identical note-duration formula Tempo-Synced Delay Calculator uses, multiplied by the stated release multiplier. This is a starting value for further ear-tuning, not a guaranteed setting; the actual perceived pumping effect depends on the compressor's threshold and ratio and on the source material's own envelope shape, none of which this tool has access to or attempts to model.
Targeting a smaller note division at the same tempo, such as an eighth note instead of a quarter, halves the computed release time, since the eighth note's own duration is half the quarter note's; a release multiplier can then fine-tune that starting value up or down without changing which pulse it is meant to align with. Two different tempo-and-division combinations can coincidentally produce the identical release figure, which is expected rather than a sign of an error, since the formula only cares about the resulting duration.