About samples and harmonics...

[Stefan Nielsen]

> From:           Sneppe Filip <sneppe at message.fucam.ac.be>
> Subject:        About samples and harmonics...
> To:             synth-diy at horus.sara.nl
> Date sent:      Mon, 16 Dec 96 10:18:19 MET

> Hello list,
> 
> I've got a question that has been puzzling my mind for quite a while
> now: If you transpose a sampled waveform up or down, do weird things
> happen with the harmonics or not ?
> In other words: Why can't you create a decent, say, violin imitation
> from just one sample. Is it because the harmonics of the original
> instrument (i.e. the violin) are different from octave to octave ?
> 
> Are there any good books out there that cover these kind of problems ?
> I would really like to know more about Fourrier analysis etc.
> 
> 
> Cheers
> 
> Filip Sneppe                                sneppe at message.fucam.ac.be

Hi Filip!

Two words: Formants and munchkinization.

Formants are nonharmonic "overtones", generated from static 
resonances in the body of a natural instrument or from plucking 
noises etc. They stay in the same place in the frequency 
spectrum in the real world and sound really weird if/when you 
transpose them.

...which leads us to word number two: Munchkinization. The word comes 
from the little people in "The wizard of Oz", and refers to their 
high-pitched mouse-like voices. It is the result of 1) Doing "le 
grande no-no": transposing formants, and 2) the fact, that most 
natural lower-register sounds are generally more loaded with overtones 
than higher-register ones.

There is this book, that (as far as i can remember?!?) was quite 
good. It's called "What's a sampler", and it is written by Freff from 
"Creative Options" in "Keyboard magazine". Hal Leonard Publishing, 
again fighting against a short memory.

Have fun,

Stefan
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