IFFT: table of contents
Classes | UGens > FFT

IFFT : WidthFirstUGen : UGen : AbstractFunction : Object

Inverse Fast Fourier Transform
Source: FFT.sc


The inverse fast fourier transform converts from frequency content to a signal.

The fast fourier transform analyzes the frequency content of a signal. The IFFT UGen converts this frequency-domain information back into time-domain audio data. Most often this is used as the end of a process which begins with FFT, followed by frequency-domain processing using PV (phase-vocoder) UGens, followed by IFFT.

Class Methods

IFFT.new(buffer, wintype: 0, winsize: 0)

IFFT.ar(buffer, wintype: 0, winsize: 0)

IFFT.kr(buffer, wintype: 0, winsize: 0)

returns a time domain signal from converting the FFT frequency domain signal chain. The *new method is equivalent to the *ar message returns an audio rate signal.



The FFT "chain" signal coming originally from an FFT UGen, perhaps via other PV UGens.


Defines how the data is windowed:

-1rectangular windowing, simple but typically not recommended;
0(the default) Sine windowing, typically recommended for phase-vocoder work;
1Hann windowing, typically recommended for analysis work.

Can be used to account for zero-padding, in the same way as the FFT UGen.


The time-domain audio signal.


The IFFT UGen converts the FFT data in-place (in the original FFT buffer) and overlap-adds the result to produce a continuous signal at its output.

Inherited class methods

Instance Methods

Inherited instance methods


// without any modification, convert FFT chain (frequency domain signal) back to audio (time domain signal)
{   var in, chain;
    in = WhiteNoise.ar;
    chain = FFT(LocalBuf(2048), in);
    IFFT.ar(chain) * -20.dbamp // inverse FFT