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Path: utzoo!linus!philabs!cmcl2!seismo!hao!hplabs!tektronix!tekchips!vice!shauns
From: shauns@vice.UUCP (Shaun Simpkins)
Newsgroups: net.audio
Subject: Re: Sheffield CDs and why they sound bad
Message-ID: <49@vice.UUCP>
Date: Mon, 15-Oct-84 13:21:31 EDT
Article-I.D.: vice.49
Posted: Mon Oct 15 13:21:31 1984
Date-Received: Sat, 20-Oct-84 07:07:50 EDT
References: <46@vice.UUCP> <1183@hou4b.UUCP>
Organization: Tektronix, Beaverton OR
Lines: 18

If I remember my dbx specs right the vca has an attack time of less than a
millisecond and a much longer decay time.  They give some reasons relating to
audibility of the gain riding for these times and suggest mightily that they
are black magic.  Who am I to argue?  Anyway, this implies a control track
bandwidth of at least 1KHz, perhaps 2 or 3KHz.  Roughly speaking, every tenth
word will be a control word if the control track is interleaved with the
normal CD data stream.  So, perhaps 10% play time reduction, not 30-50%.
100Hz compansion contoller BW sounds way too slow \- in particular for isolated
percussive sounds, the bane of compression systems.

The wandering squash,

-- 
				Shaun Simpkins

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