[sdiy] Fourier Analysis Question

[Magnus Danielson]

On 12/18/2010 11:32 AM, Tom Wiltshire wrote:
> Richard,
>
>> You can, but FFTs are almost useless for analysing fast attacks, because the window size isn't small enough to capture the partial movement within the attack.
>
> Yeah, I realise. For the work on attacks, I was using a different approach. I have a whole series of different attack and decay curves, and I wrote a script which exhaustively tries all the different combinations and times and keeps track of the best fit. Essentially we assume that a synth could do a reasonable job of copying this envelope, then we see which synth envelope is the best fit.
> The hope was that I'd be able to capture some data about average attack length vs pitch and velocity to see if there are useful patterns. And by getting an algorithm to do it, it becomes "objective" in some sense that it doesn't when I just pick a point as the boundary between attack and decay.

Have you done Z-transform analysis rather than pure FFT?
For transient signals it should be more applicable than FFT.

The location of poles and zeros might be illustrative. Just a thought.

Cheers,
Magnus