@audio/measure-align

Status calibrated

npm1.0.2licenseMIT

Multi-mic phase/time alignment — signed cross-correlation delay + polarity (Auto-Align class)

Overview

Install
Updated: 2026-10-12
Family: measure, 7 packages under it
Tags: measure

import align from '@audio/measure-align'

Signed cross-correlation peak between two channels gives the delay and polarity of b relative to a; pass apply: true to also get b shifted into alignment and polarity-corrected.

align(a, b, { fs })                       // { delay, seconds, polarity }
align(a, b, { fs, apply: true })           // + { aligned }

Param	Default
`a`	—	reference channel (`Float32Array`)
`b`	—	channel to align (`Float32Array`)
`fs`	`44100`	sample rate
`apply`	`false`	when `true`, also return `aligned`: `b` shifted by `delay` and polarity-flipped

Returns:

Field
`delay`	`number`	samples `b` lags `a` (signed)
`seconds`	`number`	`delay / fs`
`polarity`	`1 \| -1`	polarity of `b` relative to `a`
`aligned?`	`Float32Array`	present only when `apply: true`

Use when: multi-mic recordings (drum overheads, DI + amp blend, room + close mics) need per-channel delay and polarity correction before summing — comb-filtering from misaligned mics is inaudible per-track and destructive on sum.

Part of @audio/measure — the measure family umbrella.