[sdiy] Generating acyclic waveforms?

[Tom Wiltshire]

Does anyone (physicists?) on the list know whether this harmonic  
stretching occurs only with strings, or do similar things happen in  
wind instruments? reeds?

What I'm really asking is whether this is a 'string' effect or an  
'acoustic' effect.

Thanks,
Tom



On 21 Mar 2010, at 16:58, cheater cheater wrote:

> Most people here know that in piano timbre the partials are sine waves
> that are not spaced like in synth waveforms. That is, in the
> synthesizer, if the note's fundamental frequency is F, then harmonics
> will be at 1F, 2F, 3F, 4F etc. In a stretched-harmonic waveform, the
> frequencies will for example be of the form 1sF, 2sF, 3sF, 4sF, and so
> on, where s is the stretching factor. For s=1 we have the usual
> harmonic series. For s which is not an integer and not a specially
> chosen rational number, we have a probability of 100% of generating an
> acyclic waveform. Of course, the spacing of harmonics in the piano is
> more complex than that, but this is the first approximation.