Hallo, mescalinum@gmail.com hat gesagt: // mescalinum@gmail.com wrote:
today I start learning FFT, and after seeing the (hann) windowing function, I realized this (attached) filter with custom frequency response, but I suspect something is wrong here
why it sucks (given that it does)?
First as others wrote you should use block overlaps.
The delay strategy, David (pspunch) suggested isn't necessary with overlap using [block~ 512 4] as the block~ object does an internal delay automatically (four times in this case)
Then it's important for windowing that you also *window the outgoing signal* after the inverse FFT, otherwise you get these bad artifacts.
Check the I03.resynthesis.pd example in the docs for a complete example, the corresponding chapter in Miller's book and maybe my "FFT for dummies" guide here: http://footils.org/cms/show/60 (though this doesn't explain overlap)
Ciao
Frank Barknecht _ ______footils.org__