Delay & Reverb

Normal, dotted, and triplet values

A quarter note lasts one beat. Every other subdivision is derived from that beat length, so the same rhythmic relationship survives at any tempo.

Dotted values are 1.5 times the normal duration. Triplet values are two-thirds of it. That simple change moves the repeat away from the straight grid and changes the perceived momentum without changing BPM.

• Normal 1/4 or 1/8: stable echoes, slap layers, and predictable rhythmic reinforcement.
• Dotted 1/8: a classic off-beat pattern that stays active between quarter-note pulses.
• Triplet 1/8 or 1/4: rolling repeats that suit swing, shuffle, and three-against-two movement.
• Hertz: useful for tempo-syncing LFO rate, tremolo, auto-pan, chorus, or filter modulation.

Pre-delay, decay, and total time

Pre-delay is the gap between the dry sound and the start of the reverb. A little separation can protect a vocal consonant, snare transient, or lead attack while still placing it in a space.

The suggested total is a musical target aligned to a note value. auroLab subtracts pre-delay from that target to produce the decay value shown in the table.

• Short pre-delay blends the source into the room and can push it farther back.
• Longer pre-delay keeps the dry source forward, but too much can sound like a separate echo.
• RT60 traditionally describes a 60 dB decay in an acoustic space. Plug-in decay controls do not always map to RT60 in exactly the same way.

Translate the table into a mix decision

For a lead vocal, try a very short subdivision for pre-delay and a half-note or whole-note tail. Raise the pre-delay if the words lose definition; shorten the tail or filter the return if phrases overlap.

For drums, a quarter-note ambience can add size without filling every gap. Let a snare tail approach the next backbeat, then pull it slightly shorter so the groove can breathe.

• Width: offset left and right delays by related note values rather than duplicating the same tap.
• Movement: automate feedback or send level at phrase endings instead of leaving a dense delay running constantly.
• Depth: keep the dry signal clear and darker, quieter repeats behind it; brighter repeats tend to feel closer.
• Cohesion: one shared room send can place several instruments in the same imagined space.

When a mathematically correct value sounds wrong

Tempo alignment does not guarantee a clean arrangement. The source envelope, playing density, feedback, stereo placement, and spectral balance all change how long an effect feels.

• Muddy or crowded: lower the send, shorten decay, reduce feedback, and high-pass the wet return.
• Detached from the source: shorten pre-delay or choose a smaller subdivision.
• Too static: combine related subdivisions, pan taps, or automate only the last word or hit.
• Too obvious: darken the repeats, lower feedback, or move from dotted/triplet timing to a straight value.
• Still not working: turn sync off and adjust by ear. Musical intent outranks the grid.