pre delay reverb calculator

What Is Pre-Delay in Reverb?

Pre-delay is the small time gap between the dry sound and the start of the reverb tail. In practical terms, it lets your original signal speak clearly before the ambience blooms. That tiny delay can be the difference between a vocal that feels crisp and forward versus one that sounds washed out.

When you tempo-sync pre-delay, the reverb becomes musical instead of random. The reflections line up with the groove, helping your mix feel tighter and more intentional.

How the Calculator Works

This tool uses a simple timing formula based on quarter notes:

Pre-delay (ms) = (60000 / BPM) × Note Division × Feel Modifier + Offset

• BPM: your song tempo.
• Note Division: the rhythmic value (for example 1/16 or 1/8).
• Feel Modifier: straight (1.0), dotted (1.5), or triplet (0.6667).
• Offset: optional fine-tuning in milliseconds.

You can also enter an existing pre-delay value to find the nearest tempo-synced note value, which is useful when reverse-engineering presets.

Best Starting Points by Source

Vocals

Start around 20–45 ms. This keeps intelligibility while adding depth. If words blur, increase pre-delay slightly before reducing reverb level.

Snare

Try 10–30 ms for tight plates, or 30–60 ms for wider, dramatic tails. Match pre-delay to the backbeat feel.

Guitars and Keys

For rhythm parts, shorter settings often stay cleaner. For lead lines, longer synced values can add space without masking attack.

Drum Room / FX Returns

Very short values (0–15 ms) glue elements together. Longer synced values can create audible slap before the reverb, useful for stylized production.

Mix Tips for Cleaner Reverb

• EQ your reverb return: high-pass mud below 150–300 Hz, and tame harsh highs if needed.
• Automate reverb send: increase in transitions, reduce in dense sections.
• Match decay to tempo: long decay plus long pre-delay can quickly overcrowd a fast mix.
• Use mono checks: stereo reverbs can feel huge but collapse unpredictably.
• Trust context: calculate first, then adjust by ear 2–10 ms for pocket.

Common Mistakes

Using only one pre-delay for the whole mix

Different elements need different timing. A vocal plate and a snare hall rarely want the same pre-delay.

Ignoring arrangement density

Busy choruses usually need shorter or lower reverb settings than sparse verses.

Over-chasing numbers

Tempo sync is a starting framework, not a rule. If a non-synced value sounds better, keep it.

Quick Workflow

1. Set your song BPM in the calculator.
2. Pick a likely division (start with 1/16 straight).
3. Apply result to your reverb pre-delay control.
4. Adjust by ear in small increments.
5. Compare in full mix, not solo.

Final Thought

A great pre-delay setting creates separation, clarity, and groove at the same time. Use this calculator to get close quickly, then trust your ears for the final 10%.