From Mark Kolmar Sent Tue, Apr 27th 1999, 05:08
From Mark Kolmar Sent Tue, Apr 27th 1999, 05:08
In case anyone else is interested... The formula (for equal temperament, let's not complicate matters) is freq = freq * [ 2 ^ ( n / 12 ) ] where n is the number of half-steps to transpose. C to D is two half-steps. A is 440Hz. Frequency of a half-step up is freq * 1.059463094359 If you transpose up, the duration is shorter: dur = dur / [ 2 ^ ( n / 12 ) ] For each half step up the duration is dur * 0.9438743126817 == dur / 1.059463094359 This should be enough math to put together a chart. If you use a program like Sound Forge, it will do half the work for you, so you can see the ratios or change pitch without changing duration. --Mark __ Burning Rome : SENSELESS CD on Mindfield Records MindCD03 Cathartium 14 > Distributed by Dutch East India Trading, Com Four, and Carrot Top < < http://www.xnet.com/~mkolmar/BurningRome > < MP3 & RealAudio tracks > On Tue, 27 Apr 1999, Stuart McDonald wrote: > Does anyone have a rough and ready chart for timestretching samples to > different pitches? Say I have a sample in C and I want it in D: what's the > amount of stretching required to tune it to D without the sample > playing time being any longer than before? > > Stuart > > _______________________________________________________________________________ > Heh heh heh. > _______________________________________________________________________________ > >