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Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!olivea!uunet!mcsun!ukc!dcl-cs!gdt!exspes
From: exspes@gdr.bath.ac.uk (P E Smee)
Newsgroups: rec.audio,comp.dsp
Subject: Re: Good speaker + DSP == perfect speaker?
Message-ID: <1991Mar27.103833.27711@gdr.bath.ac.uk>
Date: 27 Mar 91 10:38:33 GMT
References: <1991Mar22.171203.8665@sco.COM>
Reply-To: P.Smee@bristol.ac.uk (Paul Smee)
Organization: University of Bristol c/o University of Bath
Lines: 31

In article <1991Mar22.171203.8665@sco.COM> jfischer@sco.COM (Jonathan A. Fischer) writes:
>	So you buy a programmable DSP "package," containing the DSP
>unit (which also performs as a frequency generator), and a mike or
>Sound Pressure Level meter.  You set up the SPL meter in your
>listening spot, press the "setup" button on the DSP unit, and it
>commences to send frequency sweeps through your sound system, reads
>the levels and the phase response.  Finally, using these variables, it
>sets up a digital equalization + phase doctoring DSP program which
>will transform your sound system, no matter what your room's or your
>speaker's acoustical properties, into one with a completely flat
>frequency response curve, and with zero phase shift across the entire
>spectrum.

Marantz are said to be working on such a box for the home market.
They've even demonstrated a prototype, which will 'flatten' naked cone
drivers in a normal room.  Of course (to answer someone else's
comments) it will only flatten them over the frequency range that the
laws of physics, and the basic limitations of the components, allow.

Knowing audio companies, 'prototype' in this context probably means
that they've got the user interface of the box completed, but with a
fairly hunky computer simulating the internal workings.  Still, with
the miracles of modern chippery, should get there eventually.  Would
surprise me if other companies aren't researching this as well.

We'd note also that since it uses digital processing, there will be
lots of folk who won't like it, no matter how good it is.

-- 
Paul Smee, Computing Service, University of Bristol, Bristol BS8 1UD, UK
 P.Smee@bristol.ac.uk - ..!uunet!ukc!bsmail!p.smee - Tel +44 272 303132