From: cwatters@magnus.acs.ohio-state.edu (Coyt D Watters)
Newsgroups: comp.sys.ibm.pc.soundcard
Subject: Re: GUS Temporal displacement.
Date: 17 Dec 92 13:39:44 GMT
Article-I.D.: magnus.1992Dec17.133944.18234
Organization: The Ohio State University

In article <1992Dec17.073432.16119@cs.hope.edu> turkstra@smaug.cs.hope.edu (Screwtape) writes:
>From article <BzD92M.4Lx@watserv2.uwaterloo.ca>, by ptran@sciborg.uwaterloo.ca (Phat H Tran):
>> In article <1992Dec16.063319.6042@cs.hope.edu> turkstra@smaug.cs.hope.edu (Screwtape) writes:
>>>From article <BzC3A3.GpF@watserv2.uwaterloo.ca>, by ptran@sciborg.uwaterloo.ca (Phat H Tran):
>>>
>>>> BTW, anybody considering implementing temporal displacements between
>>>> the left and right channels to reproduce "truer" stereo?
>>>> 
>>>> Phat.
>>>Is the GUS hardware sophisticated enough to implement temporal 
>>>displacement?  Also, I don't see how this method would produce 
>>>a "truer" stereo than 32 voices playing (16L - 16R).  The only cool
>>>stuff I've seen done with this is in surround sound, which is 
>>>impossible with the GUS. Unless we could program it to send 16 voices 
>>>out of the line out and 16 different ones out of amp out! Hmmmm. :) 
>> 
>> Since our ears are a head's width apart, a sound coming from the side will
>> reach one ear before the other.  That's an important cue that helps us
>> determine from where a sound originated.  If we set one voice to the right
>> and another to the left, and if we can drive each voice independently,
>> then, instead of just adjusting the volume for the channels, we can also
>> add in a delay for one of the channels.  I don't know if the timing
>> resolution of the GUS is fine enough to allow for delays that are no longer
>> than the time it takes sound to traverse about a foot.
>> 
>> Phat.
>This is what I meant when I asked if the hardware is sophisticated 
>enough.  Does anyone have the answer to this?  I know the effects
>of temporal displacement on surround sound (The sound of echos from 
>the back of a concert hall being heard after the original sounds from
>the stage), but is much consumer quality equipment (Typical CD sound
>system) able to produce stereo sound with the effects of the speed of
>sound included.  To rephrase this, can a typical home quality CD sound
>system produce sounds with resolution fine enough to actually (somewhat)
>accurately reproduce displacement effects of a stereo recodring?  How
>about the typical recording equipment?  I'd pull out the books and 
>calculate how long it takes for sound to travel a heads distance,
>but I assume we can all agree we are talking about very small amount
>of time.
>	I guess the way this relates specifically to the GUS is whether
>a 44.1 sampling rate is fast enough to capture these times differences.
>-- 

If'n I'm not mistaken (which happens too often these days B^( ), isn't
44.1 the rate regular CDs use?

Actually, if you wanted to do the temporal displacement, it would probably be
easier to use two separate mono voices, and use software to introduce a delay
when playing the same sound to both sides.

-Coyt
From: yoshida@hpfcso.FC.HP.COM (Stuart Yoshida)
Date: Thu, 17 Dec 1992 15:25:07 GMT
Subject: Re: GUS vs MT-32
Organization: Hewlett-Packard, Fort Collins, CO, USA