@audio/spatial-surround

Stereo → 5.1 matrix upmix — C/LFE/Ls/Rs derivation (documented simple matrix)

npm install @audio/spatial-surround

import surround from '@audio/spatial-surround'

Stereo → 5.1 matrix upmix: C is mid content, L/R pass through, Ls/Rs are the delayed/decorrelated side signal (±), LFE is a lowpassed mono sum. A simple, documented matrix upmix — not Dolby Pro Logic decoding. Returns a new [L, R, C, LFE, Ls, Rs] array.

let [L, R, C, LFE, Ls, Rs] = surround([left, right], { surroundDelay: 0.012, lfeCut: 120 })

| Param | Default | | |---|---|---| | fs | 44100 | Sample rate | | surroundDelay | 0.012 | Ls/Rs decorrelation delay, seconds | | lfeCut | 120 | LFE lowpass cutoff, Hz |

Use when: a cheap, transparent upmix path is enough — not for decoding matrix-encoded (Dolby Surround/ProLogic) content, which needs an actual decoder.

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

MIT © audiojs