Hi there, In the following code ifft.last() is sometimes larger than 1, but when the input signal has unity gain, it shouldn't be like this. Actually, what happens, I think, is that the amplification is proportional to the overlap factor. So should setting ifft.gain to hopsize/fftsize be the correct way to handle this? thanks eduard SinOsc s => FFT fft => IFFT ifft => dac; //blackhole; 1024 => int fftsize => fft.size; fftsize/4 => int hopsize; fftsize/2 => int specsize; Windowing.blackmanHarris(fftsize) => fft.window => ifft.window; complex spec[ specsize ]; fun void transform() { fft.upchuck(); fft.spectrum( spec ); ifft.transform( spec ); hopsize::samp => now; } while( true ) { if( Std.fabs(ifft.last() > 1) ) <<< ifft.last() >>>; transform(); }