On Thursday 26 January 2006 15:47, Wolfgang Woehl wrote: >bkhl@xxxxxxxxxxxxxxx (Björn Lindström): >> Wolfgang Woehl <tito@xxxxxxxxxx> writes: >> > Ismael Valladolid Torres <ivalladt@xxxxxxxxxxx>: >> >> I don't see any reason to work at 192KHz. Apart from >> >> huge files, Nyquist is on my side. >> > >> > Wouldn't interference of 2 or more signals from above the >> > audible band have the potential to produce energy within >> > the audible band? >> >> If so, you have already recorded it, haven't you? > >Discrete signals? In a recording situation, there is always the possibility of aliasing, and once thats in the digital data, it cannot be seperated by any other means than a resample with a canceling phase signal. As the original phase is unknown, there isn't much chance of ever getting it back out of the data. Aliasing is what happens when you record something with a doppler motion detector running, and the recorder doesn't have a brick wall filter thats at least 80 db down at half the sampling frequency and above. The resultant playback will have a nominally .1 to 5 kilohertz tone superimposed, and thats the diff between the 44.1khz sampling frequency and the doppler burglar alarms normal running frequency. Admittedly thats an extreme demo, but its a pretty good one if you'd like to try it. It doesn't need more than a 5 dollar microphone either. Personally, I find aliasing distortion so unpleasant that I'll waste the bandwidth and data storage to sample well above such man made racket. But thats just me. YMMV. -- Cheers, Gene People having trouble with vz bouncing email to me should add the word 'online' between the 'verizon', and the dot which bypasses vz's stupid bounce rules. I do use spamassassin too. :-) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2005 by Maurice Eugene Heskett, all rights reserved.
