[sdiy] Harmonic bandwidth

[Ben Lincoln]

Peter Keller wrote:
> The only thing I know of concerning "smearing" in a DFT is something
> called "spectral leakage". It is what happens when you have a strong
> frequency component that doesn't fall nicely into one of the specific
> frequency channels the DFT is producing. The power of the original has
> to go somewhere so it is spread out around the logical place where the
> frequency should be in the DFT. As for how wide the spread is, I couldn't
> tell you since I'm not that intimate with the mathematics.
>   
Interesting. I will have to read more about that and see if it's what 
I'm running into.
> So, I would interpret his meaning as saying that he is sort of redefining
> a harmonic from being instead a single frequency to being a band of
> frequencies centered around the traditional definition of the single
> frequency harmonic. Mathematically, what he describes doesn't have to
> be the result of a DFT exhibiting spectral leakage and can exist in
> continuous mathematics as real functions.
>   
Yes, sorry, I should have phrased what I wrote in a better way. I agree 
that the main part of his approach is to replace pure harmonics with 
clusters of closely-spaced (frequency-wise) sine waves. What I meant was 
that since he lists the phase aspect as a separate step, that he was 
using it to "smear" the harmonics in a different way to alter or 
increase the complexity of the effect that he obtains with the previous 
step.