Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site lcuxc.UUCP Path: utzoo!watmath!clyde!burl!ulysses!gamma!pyuxww!lcuxc!wjm From: wjm@lcuxc.UUCP (B. Mitchell) Newsgroups: net.audio Subject: Re: CD Musings Message-ID: <147@lcuxc.UUCP> Date: Tue, 15-Jan-85 11:12:22 EST Article-I.D.: lcuxc.147 Posted: Tue Jan 15 11:12:22 1985 Date-Received: Wed, 16-Jan-85 05:57:13 EST Organization: Bell Communications Research, Inc. Lines: 23I found Bob Niland's comments about CD's quite interesting and agree with them. However, I have some problems with gould!jon's comment about the 44 kHz sampling rate being adequate. He is correct in stating that a 44 kHz sampling rate will perfectly reproduce a 22 kHz signal (the Nyquist sampling theorem). However, that is not the problem. The problem is that, frankly, 22 kHz may not be adequate for *true* high fidelity reproduction. Although the medical texts state that Homo Sapiens can hear frequencies between 20 Hz and 20 kHz, these figures refer to the Fundamental frequencies. (and that isn't totally true either, some people, like myself, can hear 25 kHz tones - which is why ultrasonic alarms in department stores make me reach for the Excedrin). However, musical instruments do not produce pure sine wave tones, but rather complex waveforms with high amounts of harmonics. Since the third harmonic of a 14 kHz cymbal or bell note is 42 kHz, 22 kHz is nowhere near adequate for proper reproduction. Long term readers of net.audio will remember that this has always been one of my main concerns about the current CD standard. This is NOT and should NOT be interpreted as an anti-digital comment, I just want the digital sampling rate to be high enough to reproduce ALL the musical information. Regards, Bill Mitchell ({ihnp4!}lcuxc!wjm)