The frequency
property of the BiquadFilterNode
interface is an a-rate AudioParam
— a double representing a frequency in the current filtering algorithm measured in hertz (Hz).
Its default value is 350
, with a nominal range of 10
to the Nyquist frequency — that is, half of the sample rate.
An AudioParam
.
Note: Though the AudioParam
returned is read-only, the value it represents is not.
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).
const audioCtx = new AudioContext();
const analyser = audioCtx.createAnalyser();
const distortion = audioCtx.createWaveShaper();
const gainNode = audioCtx.createGain();
const biquadFilter = audioCtx.createBiquadFilter();
const convolver = audioCtx.createConvolver();
source = audioCtx.createMediaStreamSource(stream);
source.connect(analyser);
analyser.connect(distortion);
distortion.connect(biquadFilter);
biquadFilter.connect(convolver);
convolver.connect(gainNode);
gainNode.connect(audioCtx.destination);
biquadFilter.type = "lowshelf";
biquadFilter.frequency.value = 1000;
biquadFilter.gain.value = 25;