Delay and tempo
How to work out the delay time in milliseconds from the tempo, so echoes lock to quarters, eighths or dotted eighths.
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Content under musical review. It may contain inaccuracies.
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How to work out the delay time in milliseconds from the tempo, so echoes lock to quarters, eighths or dotted eighths.
Applied
Delay repeats the signal after a fixed time. If that time matches a rhythmic value in the song, the echoes become part of the groove instead of smearing it. All it takes is a simple calculation from the tempo.
One note per beat at 120 beats per minute: each quarter note lasts half a second, 500 milliseconds:
If the echo lands halfway, it falls on the eighth note, every 250 milliseconds:
The value the echo lands on is a subdivision of the beat. Change the subdivision and watch where each hit falls:
Use the tempo calculator to get the milliseconds for each note value from a BPM:
Work out times at 120 BPMIf you don't know a song's tempo, tap the beat with the metronome and adjust it until it matches:
Metronome at 120 BPM in eighthsThe basic formula is:
milliseconds per quarter note = 60,000 ÷ BPM
From there:
| Note value | Calculation | At 120 BPM | At 100 BPM |
|---|---|---|---|
| Quarter | 60,000 ÷ BPM | 500 ms | 600 ms |
| Eighth | quarter ÷ 2 | 250 ms | 300 ms |
| Dotted eighth | quarter × 0.75 | 375 ms | 450 ms |
| Eighth-note triplet | quarter ÷ 3 | 167 ms | 200 ms |
| Sixteenth | quarter ÷ 4 | 125 ms | 150 ms |
Other delay controls:
Very short delays, a few tens of milliseconds, aren't heard as separate echoes but as a thickening of the sound, the basis of doubling and chorus effects.
A dotted-eighth echo with two or three repeats turns a simple eighth-note line into a sixteenth-note pattern: your notes and the echoes interleave. Play steady eighths at 120 BPM with the delay at 375 ms and hear a rhythm appear that you aren't playing.
A delay time is the inverse of a frequency: 500 ms equals 2 repeats per second, that is, 2 Hz. The same relationship lets you sync a tremolo's or chorus's rate to the song: an eighth-note tremolo at 120 BPM pulses at 4 Hz. Owsinski applies these sums to reverb as well, setting its pre-delay and tail so they breathe with the tempo.