Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 exptools 1/6/84; site ihu1g.UUCP Path: utzoo!watmath!clyde!burl!mgnetp!ihnp4!ihu1g!fish From: fish@ihu1g.UUCP (Bob Fishell) Newsgroups: net.audio Subject: Re: CDs don't you just love them?? Message-ID: <428@ihu1g.UUCP> Date: Tue, 12-Jun-84 12:25:24 EDT Article-I.D.: ihu1g.428 Posted: Tue Jun 12 12:25:24 1984 Date-Received: Wed, 13-Jun-84 01:03:10 EDT References: <4@sunybcs.UUCP> Organization: AT&T Bell Labs, Naperville, IL Lines: 29 Square wave response in CD players varies with the type of filtering used. In general, those with digital filters tend to produce square wave responses that are less ragged on top. However, it has to be pointed out that musical instruments don't produce square waves, and that square wave response is, at best, a very rough measure of the frequency response of a system. If you want to see some ugly square waves, hook up a function generator to your amplifier, put some low-amplitude square waves through your system, and hook the 'scope up to a microphone placed at any convenient distance from your speakers. That's right, *your* speakers; I don't care what kind they are or how much you paid for them. You will see "square" waves that are considerably more distorted and ragged on top than any CD player produces. Does this mean your speakers are no good? Of course not, for the very reasons mentioned in the preceding paragraph. I don't know why you digiphobes don't appreciate CD technology, but I do know that none of you has yet come up with solid technical evidence for the abberations you purport to hear. Yes, there's a phase shift with multipole Butterworth filters, and yes, there's a sharp rolloff above 22 Khz. However, the fact remains that most people can't hear whatever effects these phenomena produce. Now, I believe that you really don't like what you hear from CDs, but you'll have to do a little better than citing poor square wave response as a reason. -- Bob Fishell ihnp4!ihu1g!fish