Tutorials and Topics - Peabody Computer Music

Tutorial 26Frequency domain signalprocessing using pfft~You can readily see on the left-hand side of this subpatch that the amplitude values of theinput signals are multiplied together. This reinforces amplitudes which are prominent inboth sounds while attenuating those which are not. The phase response of the first signalis unaffected by complex- real multiplication; the phase response of the second signalinput is ignored. You will also notice that the right-hand side of the subpatch ismathematically equivalent to the left, even though it uses only one cartopol~ object.Toward the beginning of this tutorial, we saw an example of the multiplication of tworeal/imaginary signals to perform a convolution. That example was kept simple for thepurposes of explanation but was, in fact, incorrect. If you wondered what a “correct”multiplication of two complex numbers would entail, heres one way to do it:The correct method for doing complex convolutionHere’s a second and somewhat more clever approach to the same goal:214