Robin Bowes;170578 Wrote: > > I'm not sure what you're trying to say here. Is "commensurate" the > word > you really meant to use? > > Can you clarify please? > > R.
By commensurate I mean related by an integer or simple rational number, as totoro correctly says. To be specific, I tried this with 200 and 400 Hz, with 200 and 300, and with 200 and 341. With the first two phase differences were clearly audible, with the last, not. I think I understand why this is the case, at least up to a point. If the frequencies are commensurate it means the waveform will be periodic, and different relative phases will give you very different periodic waveforms. A trivial example is if the two waveforms have the same frequency - they if they are in phase they add, but if they are out of phase they cancel completely, which is clearly audible :-). On the other hand if the frequencies are incommensurate the waveform is not periodic, but rather what's called quasiperiodic or almost periodic, and different relative phases don't change the waveform much qualitatively (this is easy to see by eye). So it's pretty clear that for incommensurate frequencies the relative phase can't matter. The only exception to this I can see is when the frequencies are very close together, so that you hear beating - in that case the phase of the beats is determined by the relative phase, which you may consider an audible effect (for example if the tone lasts for a time not much longer than the period of the beats). For real music I'm skeptical this will matter. Still, it would be interesting to play with real tones that are pretty pure. I may try recording my trumpet and then feeding it through an all-pass crossover to see if it makes a difference. -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=31590 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
