Timothy Place

In the second in our series on using the FFT in Max, spend 30 minutes exploring FFT windowing and applying this new knowledge to the noise reduction and Forbidden Planet patches we built in Part 1.

Explore FFT windowing and apply this new knowledge to the noise reduction and Forbidden Planet patches we built in Part 1. Get the patches: https://cycling74.com/2017/02/07/advanced-max-ffts-part-2/

Advanced Max: FFTs, Part 2

Download the patch used in this tutorial.

All the tutorials in this series: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7.

advanced-max-ffts-part-2

Great tutorial. Looking forward to part 3 already. How could you store different fft frames, in a file or a matrix for later re-use?

Great tutorial.  Looking forward to part 3 already. How could you store different fft frames, in a file or a matrix for later re-use?


 (data written in a matrix), or in the Max examples, Extras -> Examples Overview -> MSP -> phase-vocoder-sampler (data written in a buffer~).

@Graeme: yes, you can. For instance these tutorials (data written in a matrix), or in the Max examples, Extras -> Examples Overview -> MSP -> phase-vocoder-sampler (data written in a buffer~).


The windows in the fft-noise-reduction subpatch should have been squared to be correct. See also "MSP Analysis Tutorial 3: Using the FFT" in the Max Reference documentation.

^oh, i finally understand what Arthur above was trying to say: they meant "should have been passed through square-root..." (squared would be the opposite where it might be multiplied by itself, and i tried that also, but when they sum in 'overlap-add', it's not as ideal as when simply summing a straight Hanning window...)

and i believe the "MSP Analysis Tutorial 3: Using the FFT" in the Max Reference documentation only did this because it starts with a 'triangle' window

but Tim's way is probably more useful as something like a 'hanning' window is nicely summed with the overlap-add technique to remain at a constant of '1', especially where overlap is left at '2':

Screenshot 2023-01-31 at 6.47.32 PM.png

^oh, i finally understand what Arthur above was trying to say: they meant "should have been passed through square-root..." (squared would be the opposite where it might be multiplied by itself, and i tried that also, but when they sum in 'overlap-add', it's not as ideal as when simply summing a straight Hanning window...)
and i believe the "MSP Analysis Tutorial 3: Using the FFT" in the Max Reference documentation only did this because it starts with a 'triangle' window
but Tim's way is probably more useful as something like a 'hanning' window is nicely summed with the overlap-add technique to remain at a constant of '1', especially where overlap is left at '2':