Apr 3, 2012 at 10:21am



I am a beginner!!
I’ve been having problems understanding how to convolve in max msp.
I have been using the pfft~ object.
Do you just input the IR signal? or input the IR and an input signal into the left inlet of the pfft~ object?
If not where do these signals go?

I have a lot more questions but I think this needs to be asked first.

many thanks

Apr 3, 2012 at 2:29pm

THIS type of convolution wont really work with pfft, because it is too short.
mirroring an impulse response required to do each sample of A with each sample of B.

there is a third party deconvolution object, you might use this. (building a mirrored
file is the same process than using it later as filter or reverb.)


p.s. i think its called tconvolve~

Apr 3, 2012 at 5:10pm

thank you Roman Thilenius.

Would I use fft~ and ifft~ objects to make the IR as a reverb plug-in?

Maybe this would be easier than trying to include the input signal at the beginning

Apr 4, 2012 at 4:39pm

i am not sure how to write your own using ifft or pfft object, but i thin i can foresee that it will eat up too much CPU anyway.

what will work as an example is to implement it using buffir~.

but of course that has a certain sample limit as well, and wont do much more than a cheap sounding 2-band EQ or one first reflection for a verb. :)

is there a reason why you want to do your own code in MSP? i think its easier to use soundhack, peak, or matlab.

the download for those HISS tools is still dead … anyone?


Apr 4, 2012 at 10:28pm

alex harker has made an impulse convolver as part of his suite of objects announced in this thread

i think in the help files there’s a reverb via convolution example

Apr 6, 2012 at 11:17am

Hi, thanks for your help!!

I have decided to use the fft~ and ifft~ objects. Which seems to be working okay. However the output signal produced is slightly distorted and quiet… any tips for getting rid of them?


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