Newsgroups: comp.speech
Path: lyra.csx.cam.ac.uk!warwick!uknet!festival!news
From: jwaf@ee.ed.ac.uk (Justin W A Fackrell)
Subject: Re: Sound Blaster Filters????
References: <Cv3K76.C3A@freenet.carleton.ca>
Message-ID: <CvE8uC.KL7@festival.ed.ac.uk>
Sender: news@festival.ed.ac.uk (remote news read deamon)
Reply-To: jwaf@ee.ed.ac.uk
Organization: University of Edinburgh, Electrical Engineering Dept.
Date: Wed, 31 Aug 1994 09:54:11 GMT
Keywords: Sound Blaster, Gravis, card, filter
Lines: 28

Hi - I am also interested in finding out more about Soundcards.  We bought a
Gravis card recently, and there's no documentation with it concerning its
technical make-up at all.  We have written to Gravis but have had no reply to date.

If anyone has any info on these interesting creatures, please mail me direct and
I will post a summary in time.

I would hazard a guess that they work in the following way
1. apply analogue anti-alias filter with cut-off f_max/2 (where f_max is the 
	fastest rate available).
2. sample @ f_max.
3. apply digital filters and subsample if a lower rate is required.

Anyone know more ?

thanks in anticipation

Justin Fackrell
Dept of Electrical Engineering
University of Edinburgh

email:	J.Fackrell@ed.ac.uk
WWW:	http://www.ee.ed.ac.uk/~jwaf/





