Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site watdcsu.UUCP Path: utzoo!watmath!watdcsu!herbie From: herbie@watdcsu.UUCP (Herb Chong [DCS]) Newsgroups: net.audio Subject: Re: stereo Message-ID: <1059@watdcsu.UUCP> Date: Sun, 3-Mar-85 14:18:44 EST Article-I.D.: watdcsu.1059 Posted: Sun Mar 3 14:18:44 1985 Date-Received: Mon, 4-Mar-85 06:33:24 EST References: <630@houxa.UUCP> <191@moncol.UUCP> <86@vice.UUCP> Reply-To: herbie@watdcsu.UUCP (Herb Chong [DCS]) Organization: U of Waterloo Lines: 36 Summary: In article <86@vice.UUCP> winkg@vice.UUCP (Wink Gross) writes: >"image height"? Would someone please explain how stereo with only >two channels could convey any spatial information on an axis perpendicular >to the line between the speakers? > > Wink Gross > Tektronix the height that can be heard is produced by psychoacoustics at work and has little, it any correlation, with the actual vertical placement of the instruments. it seems that when pure tones are heard, certain frequencies seem to come from specific directions no matter where the actual sound source is. speakers with vertical imaging do this to some extent. also, speakers are not ideal point sources with the tweeter and bass drivers separated. phase differences between different parts of the spectrum of the played instruments emulate to some extent what happens when these instruments are played close to reflecting surfaces of different sound absorption properties. since there are no such surfaces in the right places, the eyes force the brain to do other things to come up with something resembling reality. you end up getting the illusion of vertical placement. only good recordings with well recorded ambience and extremely low distortion will provide this effect, and excellent equipment is required to reproduce it. simpler microphone techniques tend to show this better. Audio, a year or so ago, had a very good article on psychoacoustics. more importantly, they have citations at the end of their articles so that you can do more research. i'm sorry, but i don't have the issue number or date. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu