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From: mat@hou5d.UUCP
Newsgroups: net.audio
Subject: Phase Shift -- Is It Important?
Message-ID: <746@hou5d.UUCP>
Date: Mon, 21-Nov-83 11:27:39 EST
Article-I.D.: hou5d.746
Posted: Mon Nov 21 11:27:39 1983
Date-Received: Tue, 22-Nov-83 02:57:53 EST
Organization: AT&T Information Systems Laboratories, Holmdel, NJ
Lines: 19

Cementing my reputation as a Hirsch-Head (which means "If YOU can't hear it,
it doesn't matter") I present the following.

It the December Stereo Review, in the Technical Talk column, Julian Hirsch
quotes a paper by D. Preis of Tufts Univresity, published in the 11/82
Journal of the Audio Engineering Society, reporting ``It appears that
under controlled laboratory conditions, the threshold of audibility is
about 1 millisecond from 500 to 6 000 Hz (the upper frequency limit of the
experiments), extending to about 2.5 milliseconds between 100 and 400 Hz.
Other measurements of actual group-delay distortion of seven speakers
showed peak values of seven different speakers showed peak values of
1 to 2 milliseconds from 300 to 20 000 Hz and as much as 8 milliseconds at
50 Hz.''

1 millisecond at 6 000 Hz represents six full cycles.  At 500 Hz it
represents one half of one cycle.

					Mark Terribile
					hou5d!mat