Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site whuxj.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!whuxl!whuxj!wjm From: wjm@whuxj.UUCP (MITCHELL) Newsgroups: net.audio Subject: Re: Square Wave Response Message-ID: <270@whuxj.UUCP> Date: Tue, 12-Jun-84 11:22:49 EDT Article-I.D.: whuxj.270 Posted: Tue Jun 12 11:22:49 1984 Date-Received: Wed, 13-Jun-84 00:48:03 EDT Organization: Bell Communications Research, Inc. Lines: 25Yes, one of the problems of choosing a 44.1 KHz sampling rate for CD's is that no frequency above 22.05 KHz will be reproduced. Since a square wave is composed of all odd harmonics of the given fundamental frequency, the square wave response for CD players will not look as "good" as that from analog components that can reproduce 22KHz+ frequencies (even with 5 or 10 dB of loss compared to response at 1KHz or so). What does this mean??? 1. As I've said before, I feel the 44.1 KHz sampling rate is too low - I believe that there is useful musical information in the top octave of music (10-20 KHz) and that some of the harmonics on percussion instruments go as high as 25KHz. Personally, I can hear 25 KHz (ultrasonic alarms drive me bats) and there is information there. While I realise the need for a digital standard if CD is to be a workable system, I fear we may have been locked into a standard that limits us as recording technology improves. This is the same problem that happened with the NTSC TV standard, and is now coming back to bite us when we want to develop HDTV. 2. The square wave test is very useful, since it does give some feel for the high frequency response of the system. 3. Even though no CD player can properly handle a 20 KHz square wave, the test results provide valuable information about the effects produced by the filters in the unit, by examining the amount of ringing that takes place at the corners of the square wave. Regards, Bill Mitchell (whuxj!wjm)