Path: utzoo!attcan!uunet!jarthur!elroy.jpl.nasa.gov!usc!zaphod.mps.ohio-state.edu!uwm.edu!uwm.UUCP!ames!scubed!simpact.com!jeh
From: ames!scubed!simpact.com!jeh@uwm.UUCP
Newsgroups: rec.audio.high-end
Subject: Re: (very) Unconventional Speakers
Message-ID: <2767@uwm.edu>
Date: 5 Mar 90 21:35:43 GMT
Sender: news@uwm.edu
Lines: 26
Approved: tjk@csd4.csd.uwm.edu

In article <2702@uwm.edu>, andrew@alice.UUCP (Andrew Hume) writes:
> although i can't remember the precise details, there
> are people at bell labs who have made a digital speaker;
> that is, it takes a digital bit stream and converts it directly to sound.
> there were a smallish (128? 256?) of elements involved but it
> did what they said it would do. i know nopthing about
> the scalability...
> 
> mind you, these were the same folks that made speakers
> from animal stomachs...

Why not use 16 drivers (one for each bit), in graduated sizes, 
each next-larger driver being 2x the area of the previous.  Sixteen 
power amps (per side) to move the drivers.  The amps are fed directly
from the digital bitstream (after serial-to-parallel conversion, of
course!).  For a given volume setting, all drivers always move the 
same distance; you adjust volume by changing this distance.  

It might even work, after a fashion.  I'm not sure where the 
just-above-20kHz filter would go, though.... :-)

[Please, no more silly ideas... we are trying to keep this serious! -tjk]

	--- Jamie Hanrahan, Simpact Associates, San Diego CA
Internet:  jeh@simpact.com, or if that fails, jeh@crash.cts.com
Uucp:  ...{crash,scubed,decwrl}!simpact!jeh