The IIRFilterNode() constructor of the Web Audio API creates a new IIRFilterNode object which an AudioNode processor which implements a general infinite impulse response filter.
new IIRFilterNode(context, options)contextA reference to an AudioContext.
optionsOptions are as follows:
feedforwardA sequence of feedforward coefficients.
feedbackA sequence of feedback coefficients.
channelCountRepresents an integer used to determine how many channels are used when up-mixing and down-mixing connections to any inputs to the node. (See AudioNode.channelCount for more information.) Its usage and precise definition depend on the value of channelCountMode.
channelCountModeRepresents an enumerated value describing the way channels must be matched between the node's inputs and outputs. (See AudioNode.channelCountMode for more information including default values.)
channelInterpretationRepresents an enumerated value describing the meaning of the channels. This interpretation will define how audio up-mixing and down-mixing will happen. The possible values are "speakers" or "discrete". (See AudioNode.channelCountMode for more information including default values.)
Unlike other nodes in the Web Audio API, the options passed into the IIR filter upon creation are not optional. The filter needs these values to work and with the vast range of filters available, there is no default.
A new IIRFilterNode object instance.
let feedForward = [0.00020298, 0.0004059599, 0.00020298];
let feedBackward = [1.0126964558, -1.9991880801, 0.9873035442];
const audioCtx = new AudioContext();
const iirFilter = new IIRFilterNode(audioCtx, {
feedforward: feedForward,
feedback: feedBackward,
});