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!ulysses!mhuxl!houxm!ihnp4!ihu1g!fish From: fish@ihu1g.UUCP (Bob Fishell) Newsgroups: net.audio Subject: Re: Consumer Reports and dbx Message-ID: <418@ihu1g.UUCP> Date: Mon, 11-Jun-84 14:16:02 EDT Article-I.D.: ihu1g.418 Posted: Mon Jun 11 14:16:02 1984 Date-Received: Tue, 12-Jun-84 00:51:21 EDT References: <268@whuxj.UUCP> <246@ihu1h.UUCP> <1350@vice.UUCP> Organization: AT&T Bell Labs, Naperville, IL Lines: 30 (oo) >What? I think I'll pick a few nits on this reply since I'm feeling irritable. >dbx does NOT work by preemphasizing the High frequencies of the compressed >signal, to my recollection, but does play tricks with the signal presented >to the RMS detector. High frequency response of the tape deck shouldn't have >much to do with the reconstruction quality, since the RMS detector only looks >at signals below 10kHz. >(...,) >the wandering squash, > >-- > Shaun Simpkins The following is a quote from the instruction manual issued with the dbx Model 1BX dynamic range expander (page 14): "[dbx] noise reduction is accomplished by a 'compander,' a circuit which compresses the program before recording, and expands the program during playback. In addition, dbx tape noise reduction systems apply pre-emphasis of high frequencies before recording, and de-emphasis upon playback to further reduce high frequency noise (hiss) and tape modulation noise" Now, my sources are pretty succinct. Where did you get your information? -- Bob Fishell ihnp4!ihu1g!fish