spoo@utcsrgv.UUCP (Suk Lee) (06/28/84)
> by the D/A converter. Sampling at 44kHz, a 22kHz square wave can be reproduced > exactly (alternate samples are a high voltage then a low voltage). I can't believe the utter nonsense that's been coming out of this group on this subject. The person fed a alternating series of samples at 22 kHz. into a D/A, observed the RAW output (no filtering) and them made the above claim. The point of the low-pass filter (NOT THE ANTI-ALIASING ONE) after the D/A conversion is to interpolate between the instantaneous samples and give you a continuous waveform. The person who did the "experiment" did not do so and his arguements are invalid -- the samples he fed into his D/A are indistinguishable from those of a 22kHz. sine wave, and yet he got a "square wave" out -- because he didn't set up his experiment properly. And this from a Physics Department!!!! Ack!!!!!!!! -- From the pooped paws of: Suk Lee ..!{decvax,linus,allegra,ihnp4}!utcsrgv!spoo