audioJS

@audio/eq-lowshelf

Status calibrated

npm1.1.2licenseMIT

Low-shelf filter — boost or cut below a corner frequency

Overview

Install
Updated
Family
eq, 10 packages under it
Tags
shape

RBJ low-shelf filter — boost or cut below a corner frequency

import lowShelf from '@audio/eq-lowshelf'

RBJ Audio-EQ-Cookbook shelf biquad, via @audio/biquad. One section, no cascade — fc is the shelf's mid-point (half the gain is reached there), Q sets slope.

let params = { fc: 200, gain: 3, fs: 44100 }
for (let buf of stream) lowShelf(buf, params)
Param Default
fc 200 Corner frequency, Hz
gain 0 Shelf gain, dB (positive boosts, negative cuts)
Q 0.707 Shelf slope (1 = RBJ "shelf slope = 1", steepest monotonic; lower is gentler)
fs 44100 Sample rate, Hz

Pass the same params object across successive calls — coefficients and filter memory are cached on it; a change of fc/gain/Q/fs rebuilds only the coefficients and the memory carries over, so state continues across block boundaries and automation is click-free.

Use when: warming or thinning below a corner frequency — low end, rumble region, weight; the bottom half of a Baxandall-style tone stack.


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

MIT © audiojs