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    BiquadFilterNode.Q

    This article is in need of a technical review.

    The Q property of the BiquadFilterNode interface Is a k-rate AudioParam, a double representing a Q factor, or quality factor.

    It is a dimensionless value with a default value of 1 and a nominal range of 0.0001 to 1000.

    Syntax

    var audioCtx = new AudioContext();
    var biquadFilter = audioCtx.createBiquadFilter();
    biquadfilter.Q.value = 100;

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

    Value

    An AudioParam.

    Example

    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);
    source.connect(analyser);
    analyser.connect(distortion);
    distortion.connect(biquadFilter);
    biquadFilter.connect(convolver);
    convolver.connect(gainNode);
    gainNode.connect(audioCtx.destination);
    
    // Manipulate the Biquad filter
    
    biquadFilter.type = "lowshelf";
    biquadFilter.frequency.value = 1000;
    biquadFilter.gain.value = 25;
    
    biquadFilter.type = "peaking";
    biquadFilter.frequency.value = 1000;
    biquadFilter.Q.value = 100;
    biquadFilter.gain.value = 25;
    

    Specifications

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

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
    Basic support 10.0webkit 25.0 (25.0)  Not supported 15.0webkit
    22 (unprefixed)
    6.0webkit
    Feature Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
    Basic support ? 26.0 1.2 ? ? ? 33.0

    See also

    Document Tags and Contributors

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