Setting Delay Times to Tempo

What each division actually does

Choosing a delay time is not really an arithmetic problem — the arithmetic is trivial. It is a decision about what you want the repeats to do to the rhythm.

Straight divisions reinforce

A delay set to an eighth or quarter note puts every repeat on an existing grid position. Nothing new appears rhythmically; the part just gets thicker and wider. This is the safe choice, and often the right one on a dense arrangement where anything more would compete.

Dotted divisions cross the beat

A dotted eighth is one and a half eighth notes. Repeats land between the grid positions, and the pattern takes three eighths to line back up with the beat. That creates a rolling, syncopated figure from a single note.

This is the sound on a great deal of rock guitar and electronic lead work. It is also the most likely to clutter a busy mix, because it is generating new rhythmic information rather than reinforcing what is there.

Triplets fill

Triplet delays subdivide into three where the rest of the track subdivides into two. They add density and motion without doubling the existing rhythm. Useful on sparse material, disorienting on busy material.

Setting a unit that only takes milliseconds

Plenty of hardware and older plugins have no tempo sync. Work out the value and dial it in. At 140 BPM:

If the unit only accepts whole milliseconds, round to the nearest. The error at these values is well under a millisecond and inaudible as timing drift over the length of a phrase.

Feedback and filtering matter as much as time

A correctly timed delay with the feedback too high still turns a mix to mud. Two habits fix most of it:

• Start with feedback low and raise it until the repeats are just audible as a distinct layer. On rhythmic parts, two or three audible repeats is usually plenty.
• Filter the delay return. Rolling off the low end below roughly 300 Hz and the top above roughly 5 kHz keeps repeats out of the way of the dry signal while preserving the rhythmic effect.

When to deliberately go off-grid

Tempo-synced is not automatically better. A delay a few milliseconds away from the grid produces a looser, more human feel — this is most of what a slapback delay is doing. Analogue units drift by nature, and that drift is part of why they sound the way they do.

Use the calculated value as the starting point, then move off it on purpose if the part wants it.