3-D module

[Robert Donker]

That's an artifact. It's a well established that its impossible to qualify
this in a reproducible way. It is some times true you can experience sound
coming from the rear while using just two speakers (I've had this experience
with headphones too). I worked some time on this have some professional
experience with the engineers @ QSound. The problem is consistency. Without
a reference to "lock" the listener to the effect, some will perceive as in
front, some will perceive in the rear. I use Serge quad panners. It's the
only way to go. Supporting four channels of output is expensive though.

A trick QSound would use is to start with a very dry signal, this usual
brings the listeners perception to the "front", ounce established, you can
move the signal forward towards the listener, then as the sound moves away,
it will be perceived as moving to the rear. A small percentage of listeners
will still perceive this as "bouncing" back to the front.

I've taken this offline because my information about QSound is still under
NDA. If you can solve this problem, they would be very interested.
-RP:D

-----Original Message-----
From: Tim Ressel [mailto:Tim_R1 at verifone.com]
Sent: Tuesday, May 30, 2000 2:06 PM
To: Synth-DIY
Subject: RE: 3-D module


Robert,

I'm not too sure about that, for two reasons. For one, on Larry Fast's
Sequencer
lp, Track 3 has an effect that always sounds to me like its behind me (with
headphones on). And two, just 'cause the DOD sez its so, doesn't mean it is.
Don't get me wrong, I'm not dis'en you or your research, just the DOD's.
There
might be tricks the DOD didn't think of.

Its like M.I.T. in the 60's. All these grad students sitting around
calculating
how tough it will be when someday someone gets around to making a robot
navigate
using vision and AI. Meanwhile downstairs a high-school kid hanging around
the
labs makes a robot that, using vision and AI (of sorts), finds a thrown
wallet
on the floor and scoots it to its destination.

No offense, but I will still play with it. Your help will be greatly
appreciated. 

Tim Ressel--Compliance Engineer
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com                     



-----Original Message-----
From: Robert Donker [mailto:RobertD at concur.com]
Sent: Tuesday, May 30, 2000 1:49 PM
To: 'Tim Ressel'; Synth-DIY
Subject: RE: 3-D module


This is a much more complicated problem. The ears have dynamic timbre
effects. Not just delay but pitch. Like light different pitches move through
your ears at different rates and disperse at different rates. You will also
find the front / rear can not be simulated, in the end you need four
speakers. The DOD has done a lot of research in this subject. When I was in
college I did some research on this subject. You might also look at current
technology in sound placement being done commercially like Q sound.

-----Original Message-----
From: Tim Ressel [mailto:Tim_R1 at verifone.com]
Sent: Tuesday, May 30, 2000 12:11 PM
To: Synth-DIY
Subject: 3-D module


Okay, I've gotten two nibbbles on the 3D hint I dropped, so I'll elaborate.
I
had this crazy idea to make a module with two delay lines in it to simulate
the
paths to the ears. Then I did some research and found out that you need more
than just delta delays to get 3D. But not much more (yay). 

So the beastie would be two delay lines and two oscillators rigged to vary
the
delays in such a way that 0V CV would be left (arbitrary), 5V CV would be
center, and 10V CV would be right. Then two (lowpass? not sure yet...)
filters,
one on each delay line output, to simulate the effect the outer ear has. 

This is actualy true 2D, not 3D. I am still digesting the info I have, which
is
in verbose academ-speak. You see, the academic aproach is to understand
something into the ground (with elaborate math, of course). My way is to go
play
with it as soon as possible, thus the board/module.

As I understand the technologhy more, I may be able to expand the scope. But
at
some point it may become easier to impliment in (gulp) DSP (shudder). 

Thoughts/comments/whatevers welcome.

Tim Ressel--Compliance Engineer
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com                     



-----Original Message-----
From: Barry L Klein [mailto:Barry.L.Klein at wdc.com]
Sent: Tuesday, May 30, 2000 11:54 AM
To: Tim_R1 at verifone.com
Subject: RE: Re: Been quiet lately... too much DIY ?


Tim,
If I remember right, one of the timbre modulators was from EN and another
was my own design.  The one that was my own design used several LFO's to
chop up an input signal via comparators.  The result is what can be called
"the beehive effect".  It really sounds like a bunch of bees.  Sometimes
interesting subharmonics are generated, but I don't think its worth trying
to use nonpolaraized electrolytics for the LFO's - just anything would
work.  It might be interesting to have a dual circuit and route one output
left and the other right...  more needs to be done with it.

I'm interested in the 3d module.  What were you planning?

Barry

Studied the timber modulators in Barry Klein's book... Might just have to
proto
a few of those...

Studied 3-D sound effects. Is anyone interested in a module or an
expreimenter's
kit that will do some kind of true 3-D??