audio-biquad

Biquad filter stream. API is similar to BiquadFilterNode.

var BiquadFilter = require('audio-biquad');
var Speaker = require('audio-speaker');
var Generator = require('audio-generator');

Generator(function () {
	return Math.random() * 2 - 1;
}, {
	duration: 2
})
.pipe(BiquadFilter({
	type: 'bandpass',
	frequency: 440,
	Q: 100,
	gain: 25
}))
.pipe(Speaker());

BiquadFilterNode — all the options for the filters.
BiquadFilterNode chromium source — source code inspiration.
EQ Cookbook — description of all the kinds of filters.