Hi Bill,
this dynamic sound placement is something that I have been working with on and off for a while. I presume you would like to be able to place sound arbitrarily inside the surface that the speakers enclose. This is a bit harder than placement around the ring of speakers.
The ring placement is basically a pan between the two speakers, a linear fade as opposed to a log fade used for levels. This little note is trivial when you know it, which you probably do, but vital if you dont, so I thought it good to make sure you do.
This is easy and fast, we have done a bunch of work with some equipment and sound movement using rotation as a main theme.
The placement on a surface is more dependent upon the precise arrangement in space of the surrounding triangle of speakers. I have done calculations for speakers on a regular square grid, to place a sound anywhere on that grid, but I dont have them with me. It's a bit of trigonometry and a bit complex, but nothing too much.
The sound sources we found had to have certain properties, most importantly was a lack of resonance. Most effective was some pure noise, Japanese stuff or John Duncan sort of noise tracks. Pure tones resonate too well and envelop the space. Percussivity was also a little distracting, depending upon the speed of movement relative to the beat rate. One has to ensure that the sound source doesn't disappear at one point and reappear elsewhere, unless that is the desired effect.
This is, of course, all work very much in progress, so I would love to hear about your and other people's experiences with other techniques.
Cheers,
tim
\ / TIME´S UP \ / Industriezeile 33 B -------------------------------------------- / A-4020 Linz Tim Boykett /\ ph:+43/732-787804 tim@bruckner.stoch.uni-linz.ac.at /xx\ fax: +43/732-795742 -------------------------------------------- /xxxx\ http://www.timesup.org