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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