On Mon, 4 Sep 2006, mami music wrote:
Hey guys thanks for the explanation!. goin further in the study of fft and applications, iam designing an oscilator that is capable to go from pure sine tone (fundamental harmonic) to a saw (all harmonics)...
Try a spectrum made like s(k) = k^(-1/p). When p=1 it'll give f^-1, the spectrum of (one kind of) saw wave at base frequency. When p goes towards 0, it goes through k^-2, k^-3, etc. with gradually less powerful harmonics. with p=0, it gives a division by zero, but the limit of s(k) when p->0 is s(0)=1 and s(rest)=0, which is a sinewave.
to produce a spectrum for a frequency multiple of the base frequency, just space out the s(k) using zeros. for a frequency not multiple of the base frequency, a lot of extra processing is necessary.
_ _ __ ___ _____ ________ _____________ _____________________ ... | Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju | Freelance Digital Arts Engineer, Montréal QC Canada