How to use it
- Enter the tempo in BPM, from the song, your DAW or a tap tempo tool. Decimal tempos such as 92.5 are fine.
- Read the time for the note value you want, in ms for delays and in Hz for modulation rates.
- Pick the note length for the reverb to see a pre-delay and decay that fit the beat.
The formulas
quarter note = 60,000 ÷ BPM ms
1/n note = 240,000 ÷ BPM ÷ n ms (a whole note is four beats)
dotted = note × 1.5, triplet = note × 2 ÷ 3, rate in Hz = 1,000 ÷ ms
Reverb: pre-delay = 1/64 note, decay = chosen note − pre-delay.
Worked example
At 120 BPM:
- quarter note 60,000 ÷ 120 = 500 ms, 2 Hz;
- dotted quarter 750 ms, quarter-note triplet 333.33 ms (3 Hz);
- eighth 250 ms, dotted eighth 375 ms, sixteenth 125 ms;
- whole note 2,000 ms (0.5 Hz);
- reverb to a quarter: pre-delay 2,000 ÷ 64 = 31.25 ms and decay 500 − 31.25 = 468.75 ms.
Tips
- Many delay plugins sync to the host tempo by themselves; the numbers help with hardware pedals and with plugins that only take ms.
- A delay set slightly shorter than the exact value pushes the groove forward, slightly longer lays it back.
- To find the tempo of a recording, tap along with the tap tempo tool.