[sdiy] Fourier Analysis Question

[thx1138]

On 12/17/10 4:09 PM, "Richard Wentk" <richard at wentk.com> wrote:

> 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. 
> 
> Also, pianos - like most instruments - include inharmonic partials. The whole
> point of a piano is the phasing and movement you can hear if you hold down a
> chord, and that's created by deliberate detuning of the strings.
> 
> This means no single waveform is exactly identical to any other cycle.
> 
> Discrete stepped timbre-frame synthesis won't capture that.
> 
> You can use stepped timbres for conventional synthetic wavetable synthesis,
> but there's no advantage to using FFTs instead of ROM wavetables unless you're
> recalculating them dynamically. And if you're doing that you may as well build
> a system with N DCOs controlled by partial track information that can be
> calculated, interpolated and modulated with a decent refresh rate of - say a
> few kHz.
> 
> For that approach you use FFT analysis to create a database of partial sets
> that varies with time, frequency and velocity, and then interpolate between
> partial sets dynamically as the note evolves.
> 
> I think the Hartmann Neuron used to do something like this.
> 
> R
> 
> On 17 Dec 2010, at 15:09, Tom Wiltshire wrote:
> 
>> </background>
>> 
>> So the question is this:
>> 
>> Can you break one long fourier analysis result into an approximate copy based
>> on a series of lower resolution fourier analyses without going back to the
>> time domain?
>> 
>> Any clues or comments appreciated.
>> Thanks,
>> Tom
>> 
>> 
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Hi Guys,

Julius and folks over at Stanford made some interesting work in the Mid-90's

http://en.wikipedia.org/wiki/Karplus-Strong_string_synthesis

It might help in a different approach to your question.

Terry