To: Ultrasound Daily Digest <ultrasound@dsd.es.com>
> This is very difficult to simulate with two (normal)
> speakers. (I believe someone mentioned earlier that the headphones that come
> with the GUS 3D have a sensor to determine the physical position (this, I
> think, explains why they're not just selling it as a software upgrade).
Actually, as I recall, the person said that the DEMO headphones at CES had
a magnetic sensor. I personally don't think they will be selling
sensor-equiped headphones in the real product.
It's still not clear what, if anything, Gravis will do for an upgrade from
the straight GUS either. Since the game sound track has to be rewritten to
include the positioning info, all this whizzy stuff will require native GUS
sound anyway...
DDA
------------------------------
Date: Thu, 14 Jan 1993 23:14:13 GMT
From: newcomb@enews.nrl.navy.mil (Dale Newcomb)
Message-Id: <C0v9vq.8xD@ra.nrl.navy.mil>
Subject: GUS 3D and other spatial sound techniques
To: Ultrasound Daily Digest <ultrasound@dsd.es.com>
The only problem with saying "you have 2 ears, so why can't
you do 3D sound with 2 headphones" is that ears are not anything
like headphones! If anything they are like microphones, audio-in
not audio out! One way to create 3D sound is to use 2 microphones
in the shape of ears on a head, such that the microphones input
the exact same thing that your ear drums would, then you can use
headphones to play the 3D sounds back - problem: this is not
interactive sound, which is what I'm sure the GUS 3D would really
want, instead it's good for fixed soundtracks, etc. Another method, which we use here at the Virtual Reality Lab at NRL is to
have a speaker cube of 8 speakers hooked up to a midi-processor
(we use the EMAX II from E-MU) which is driven by the computer.
Doppler-shift, volume, and dampening effects are calculated and
change the sounds accordingly while the computer also sends 3D
coordinates to the EMAX such that the spatial location of the sounds can be produced by varying the volumes of the 8 speakers surrounding you (talk about surround sound!!). This gives a very
convincing 3D effect when coupled with a visual display and is
even better if thet display is immersive (head mounted display, etc.) but let's face it, it's not a very good home-PC-based alternative and is quite expensive. The third option, which GUS
3D seems to be attempting is done by setting up certain delays and pitch,volume, etc shifts to simulate sounds coming from different directions. Through experimentation, sounds can be sampled from different locations around the microphone (even better if its one of those ears-in-head type) and their waveforms
analyzed and hopfully reproduced dynamically. I haven't done this side of the sound work so I don't know how hard it is to
do. One main problem I forsee is that with headphones (the best
way to get spatial sound out of 2 speakers) the sounds emanate from left and right, in the real world they can come from behind us etc. If a sound is behind you, some of the sound is blocked by virtue of the shape of the ears (aimed forward), headphones
don't allow this, so the software would have to try and make up for that loss, possibly a difficult task...but hopefully not beyond the expertise of Gravis (Focal Point actually)! I just got
my GUS a week ago and was hoping to use it in some homebrew virtual reality along with my powerglove, and soon I'll be able to do even more than I had hoped!
Dale Newcomb, Jr
Naval Research Lab, DC
------------------------------
Date: Fri, 15 Jan 1993 09:17:35 GMT
From: waardenb@cs.utwente.nl (Jerry van Waardenberg)
Message-Id: <1993Jan15.101735@cs.utwente.nl>
Subject: GUSDAC?
To: Ultrasound Daily Digest <ultrasound@dsd.es.com>
In article <1993Jan14.052316.281@rose.com>, francisco.perez@rose.com (francisco perez) writes:
|>
|> Date Entered: 01-14-93 00:20
|> M(>Has everyone checked out the GUSDAC on epas yet? Let's modplay use
|> M(>the gus as a quadrophonic dac or stereo-on-one.
|>
|> Can somebody please send a UUENCODEed GUSDAC and post it here if its not too
|> large? It sounds interesting, but alas, no FTP access for me...
|>
|> Later...and thanks to whoever will do it!
|> ---
|> OLX 2.1 TD Press any key to continue or any other key to quit
|> RoseMail 2.00 : RoseNet<=>Usenet Gateway : Rose Media 416-733-2285
Have you tried MODGUS (or GUSMOD?) yet? It sounds a lot better than GUSDAC, since
it does not use any kind of emulation. If only those nasty bugs could be removed!
Has someone tried to play xerxes.mod? Instead of handclapping, I get bird sounds,
violin ploings and percussion sounds. Weird! Also, sometimes samples are missing.
But still, most songs sound better than on any other mod player!
