3-D module

[Robert Donker]

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??