Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site mouton.UUCP Path: utzoo!watmath!clyde!burl!mgnetp!ihnp4!mhuxl!ulysses!allegra!mouton!karn From: karn@mouton.UUCP Newsgroups: net.audio Subject: Re: CDs don't you just love them?? Message-ID: <84@mouton.UUCP> Date: Mon, 18-Jun-84 21:21:30 EDT Article-I.D.: mouton.84 Posted: Mon Jun 18 21:21:30 1984 Date-Received: Fri, 22-Jun-84 09:56:34 EDT References: <4@sunybcs.UUCP> <3051@brl-tgr.ARPA> Organization: Bell Communications Research, Inc Lines: 22 I find it rather doubtful that any member of the species Homo Sapiens (as opposed to members of the Canis family) can hear the difference between 20 khz sine and square waves. As any high school physics text will tell you, the next harmonic present above the fundamental in a square wave is the third. This means that the difference between a 20 khz sine wave and a 20 khz square wave starts at 60 khz! Any difference you hear is certainly due to audio frequency components generated by imperfections in your amplifer and/or speakers. I suggest that those who have a real fetish for perfect-looking square waves from your CD players simply bypass the D/A reconstruction low pass filters. You will then see transitions that are limited solely by the slew rate of the D/A converter and associated analog circuitry. Of course, those of you with perfect hearing will be bothered by all of the "image" spectrums centered around 44.1 khz, 88.2 khz, etc, on up to infinity, while those unfortunates such as myself who are afflicted with abysmally defective hearing (cutting off at only 20 khz) would still have to fight off all the neighborhood dogs (at least until the tweeters go up in smoke.) But wouldn't it be worth it just to get those lovely square waves without even a trace of ripple or phase distortion? Phil