I think the use of [threshold~] is limiting you to block resolution. Audio to do correlation will give you a theoretical resolution much better than one block, at half the sampling rate, 0.015m (one and a half centimeters) for 44kHz.(?) Assuming that the mics are identical, in phase etc.
[snapshot~] seems a better choice than [threshold~] because it gives you the instantaneous vaue of a sample. But I'm not quite sure how best to use it in this context. It depends on the source, if its an impulse or if it's a periodic wave, for which correlation approach. I was reading this interesting one recently and wondered if anyone tried it > - Clip the two signals - i.e. amplify and saturate so the signals become a > series of 1s and 0s. > - XOR the result. You will use this result "X" in two ways: > 1) Integrate X to get Y > 2) Measure the variance of Y > When the variance of Y approaches zero, there is similarity. > Y itself is a measure of time shift between the signals. > This works for things like sinusoids. > Fred If it's for delocalisation/positioning of emitters where you get to decide what the sound is (and choose a nice ultrasonic sine wave) then it seems potentialy fast because it can be crudely sampled and carried out as logic. On Sat, 23 Jun 2007 22:12:53 +0200 Chris <[EMAIL PROTECTED]> wrote: > Hi, > I made a patch to locate the position of a sound source between two > microphones, which looks like this: > [adc~] > | | > | [threshold~ 0.2 100] > | | > [threshold~ 0.2 100] | > | [delay 10] > | | > [timer] > > So a number of 10ms means that the source is exactly between the two > microphones. This patch works kind of reliable and accurate. But I was > wondering if there is a better possibility with higher resolution? At > the moment I can distinguish the position with an accuracy of 1.333 ms, > means I get about 12 different values out of my tube. > > Has anyone an idea how I can get more precise readings? I thought about > comparing the amplitudes of the two waves I get, but I have no idea how > to do this or if this would be more exact. > > Thanks for any help, > Chris > > _______________________________________________ > [email protected] mailing list > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list -- Use the source _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
