Frequency response visualization

Luigi Castelli's icon

Hi there,
I am trying to put together a patch that accurately displays the frequency response of a filter. At the moment I am feeding the filter broadband noise and I am capturing its frequency response with the help of an FFT, however I am not getting good results. I am not sure how to scale the FFT output so that it is perfectly fits the range and domain of the [plot~] object. I didn't spend more time on it because it feels like I am going down the wrong path. I am open to any other solution (maybe even Jitter based) as long as accurate and precise.
I am wondering if someone has already built something along these lines and he/she is willing to share it or can simply point me in the right direction.

Thanks

- Luigi

itn_frequency_response_plot.maxpat
Max Patch

Roman Thilenius's icon


is the fft size limit in max still 4096? if yes, i would use an external app which allows an ultra high resolution and has some kind of text export feature. (supercollider? matlab?)

Luigi Castelli's icon

Yes, I believe it is... I tried an FFT of 8192 and Max ingloriously crashed.
An external app is a possibility, but I would really like to keep it in Max/MSP land, so that it would work in real-time and I could just open a patch every time I need it.