@audio/weighting-riaa

Status calibrated

npm1.1.3licenseMIT

RIAA playback (de-emphasis): H(s) = (1 + s*T2) / ((1 + s*T1) * (1 + s*T3))

Overview

Install
Updated: 2026-09-27
Family: weighting, 7 packages under it
Tags: measure, shape

RIAA playback equalization — vinyl de-emphasis curve

import riaa from '@audio/weighting-riaa'

Time-domain RIAA de-emphasis: bilinear transform (with frequency prewarping) of the analog playback curve H(s) = (1 + s·T2) / ((1 + s·T1)(1 + s·T3)), T1=3180 µs (fp1≈50.05 Hz pole), T2=318 µs (fz≈500.5 Hz zero), T3=75 µs (fp2≈2122 Hz pole) — the standard RIAA time constants, folded into a single biquad. 1 second-order section, normalized to exactly 0 dB at 1 kHz.

riaa(data)                                // in place, fs=44100
riaa(data, { fs: 48000 })
let sos = riaa.coefs(48000)               // 1 SOS section — feed digital-filter's freqz
riaa.response(20, 48000)                  // |H(20)| — the bass-boost region

Param	Default
`fs`	`44100`	sample rate — SOS recomputed when it changes mid-stream

Static	Returns
`.coefs(fs)`	`SOS`	1-section cascade at rate `fs`, for analysis/plotting
`.response(f, fs)`	`number`	`\|H(f)\|` — exact magnitude of this atom's own `.coefs(fs)` cascade, not an independent approximation

Use when: decoding a phono-preamp signal that was cut with RIAA pre-emphasis (i.e. reversing vinyl mastering's treble boost / bass cut) back to a flat response.

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