Reverb Pre-Delay & Decay Time Calculator (Tempo Synced)
Calculates sample-accurate reverb pre-delay (in milliseconds) and tempo-matched RT60 decay times (in seconds) for vocal plates, snare rooms, and orchestral halls. Prevents low-mid acoustic mud by ensuring the reverb tail cleans out before the next transient downbeat.
Audition Synthesizer & Stereo Engine
Fine-tune tone impulse, feedback repeats, stereo width, and headphone volume.
Tempo-Matched Reverb Spaces (RT60 Decay & Pre-Delay)
Pre-delays preserve up-front punch and diction; decay times clean up low-mid mud before the next musical downbeat.
Zero mud on rapid transients. Pre-delay gives punch; decay clears before next snare hit.
Warm intimate vocal space. Separates dry vocal sibilance before lush reflection blooms.
Bright snare & lead vocal plate. Pre-delay prevents masking; decay rings for exactly 1 bar.
Expansive strings, brass, and ambient keys. Decays gracefully across 2 musical bars.
Immense atmospheric wash for soundtrack and post-rock textures. Sustains across 4 bars.
To create a wide 3D stereo image without phase cancellation, set the Left channel delay to a Straight 1/8th note and the Right channel to a Dotted 1/8th note. Always sum your mix to mono on master output to verify vocal clarity.
Audio Delay & Reverb Tempo Sync Cheat Sheet
Calculated Project Tempo: 128.0 BPM • 4/4 Time Signature
Note Subdivisions Timing Matrix (128.0 BPM)
| Note Division | Straight (ms) | Dotted (ms) | Triplet (ms) | LFO (Hz) |
|---|---|---|---|---|
| 1/1 (Whole Note (1 Bar)) | 1875.00 ms | 2812.50 ms | 1250.00 ms | 0.533 Hz |
| 1/2 (Half Note (2 Beats)) | 937.50 ms | 1406.25 ms | 625.00 ms | 1.067 Hz |
| 1/4 (Quarter Note (1 Beat)) | 468.75 ms | 703.13 ms | 312.50 ms | 2.133 Hz |
| 1/8 (Eighth Note) | 234.38 ms | 351.56 ms | 156.25 ms | 4.267 Hz |
| 1/16 (Sixteenth Note) | 117.19 ms | 175.78 ms | 78.13 ms | 8.533 Hz |
| 1/32 (Thirty-Second Note) | 58.59 ms | 87.89 ms | 39.06 ms | 17.067 Hz |
| 1/64 (Sixty-Fourth Note) | 29.30 ms | 43.95 ms | 19.53 ms | 34.133 Hz |
| 1/128 (One Hundred Twenty-Eighth) | 14.65 ms | 21.97 ms | 9.77 ms | 68.267 Hz |
Tempo-Matched Reverb Decay & Pre-Delay Spaces
| Acoustic Space | Recommended Pre-Delay | Pre-Delay (ms) | Decay Time (RT60) |
|---|---|---|---|
| Tight Drum Booth / Small Room | 1/64 note | 29.3 ms | 0.47s (1 beats) |
| Vocal Studio Chamber | 1/32 note | 58.6 ms | 0.94s (2 beats) |
| Vintage 80s EMT Plate | 1/16 note | 117.2 ms | 1.88s (4 beats) |
| Orchestral Concert Hall | 1/16 note | 117.2 ms | 3.75s (8 beats) |
| Ambient Cathedral / Drone | 1/8 note | 234.4 ms | 7.50s (16 beats) |
Standard Reverb Decay & Pre-Delay Rules by Space Type
Standard pre-delay offsets and bar decay times for 120 BPM & modern tempos.
| Reverb Space | Musical Decay Target | Standard Pre-Delay | Recommended Instrument | Acoustic Goal |
|---|---|---|---|---|
| Snare Tight Plate | 1 Musical Bar (~2.00s @ 120BPM) | 1/32nd note (~31ms) | Short Tail | Tail vanishes right as next snare hits on beat 4. |
| Lead Vocal Chamber | 2 Musical Bars (~4.00s @ 120BPM) | 1/16th note (~125ms) | Medium Tail | Lets consonant diction cut through before bloom opens. |
| Drum Room / Ambiance | 1/2 Musical Bar (~1.00s @ 120BPM) | 1/64th note (~15ms) | Subtle Width | Adds glue and depth without pushing kit backwards. |
| Ambient Cathedral / Hall | 4 Musical Bars (~8.00s @ 120BPM) | 1/32nd dotted (~47ms) | Lush Wash | Cinematic synths, pads, and background choirs. |
Tempo Synchronization & Phase Coherence
- Pre-Delay Transient Protection: Setting 15ms–45ms pre-delay prevents the initial dry consonant from being masked by acoustic diffusion reflections.
- Bar-Synced RT60 Tail Decay: Matching RT60 decay time to 1 or 2 musical bars guarantees low-mid frequency build-up (200Hz–500Hz) is eliminated before the next downbeat.
- Sample-Accurate Phase Calculation: Outputs exact sample delays for Pro Tools, Ableton, Logic Pro, and FL Studio at 44.1kHz, 48kHz, and 96kHz.
Critical Errors to Avoid
Reverb Pre-Delay & Decay Time Calculator Questions Answered
How do you calculate reverb pre-delay in milliseconds?
Reverb pre-delay is calculated by dividing 60,000 by your song BPM to get a quarter note, then dividing by note subdivisions. For a standard 1/32nd note pre-delay, divide by 8 (e.g. at 120 BPM: 500 ms / 8 = 31.25 ms). For a fast 1/64th note pre-delay, divide by 16 (15.63 ms). Setting pre-delay to these exact millisecond values lets your vocal lead transient hit cleanly before the reverb opens up.
How do you calculate reverb decay time (RT60) to match tempo?
To make your reverb decay naturally before the next beat, sync your decay time to whole bars. One bar of 4/4 time in milliseconds is (240,000 / BPM). At 120 BPM, one bar is 2,000 ms (2.00 seconds). For a standard snare or vocal plate, set your reverb decay to exactly 2.00 seconds (1 bar) or 4.00 seconds (2 bars).
Why does my mix sound muddy when using reverb?
Mud in the 200 Hz to 500 Hz frequency range is almost always caused by two errors: using zero pre-delay (which smears transients) and setting an arbitrary decay time that lingers across chord changes. Syncing pre-delay and decay time to the BPM ensures each reverb bloom decays to silence right as the next chord arrives.