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The frequency property of the BiquadFilterNode interface Is a k-rate AudioParam, a double representing a frequency in the current filtering algorithm measured in hertz (Hz).

frequency's default value is 350 with a nominal range  of 10 to the Nyquist frequency — that is, half of the sample rate.


var audioCtx = new AudioContext();
var biquadFilter = audioCtx.createBiquadFilter();
biquadFilter.frequency.value = 3000;

Note: Though the AudioParam returned is read-only, the value it represents is not.


An AudioParam.


The following example shows basic usage of an AudioContext to create a Biquad filter node. For a complete working example, check out our voice-change-o-matic demo (look at the source code too).

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();

//set up the different audio nodes we will use for the app
var analyser = audioCtx.createAnalyser();
var distortion = audioCtx.createWaveShaper();
var gainNode = audioCtx.createGain();
var biquadFilter = audioCtx.createBiquadFilter();
var convolver = audioCtx.createConvolver();

// connect the nodes together

source = audioCtx.createMediaStreamSource(stream);

// Manipulate the Biquad filter

biquadFilter.type = "lowshelf";
biquadFilter.frequency.value = 1000;
biquadFilter.gain.value = 25;


Specification Status Comment
Web Audio API
The definition of 'frequency' in that specification.
Working Draft  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 10.0webkit (Yes) 25.0 (25.0)  No support 15.0webkit
22 (unprefixed)
Feature Android Edge Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support ? (Yes) 26.0 1.2 ? ? ? 33.0

See also

Document Tags and Contributors

 Contributors to this page: erikadoyle, crestonbunch, fscholz, chrisdavidmills
 Last updated by: erikadoyle,