@pmcw: How about doing a stereo design, but have each channel emanate from the far vertical sides towards the middle?
Funnily enough I have been thinking about going stereo. There are several ways to do this-- for example:
Having low frequencies on the left transitioning to high-frequencies on the right -- then having the left-channel on the bottom growing up (with intensity/volume) toward the middle and the right channel on the top growing down.
Or we coudl keep the low-frequency-left to high-frequency-right, buthave the left channel start in the horizontal middle growing down and th eright channel start in th ehorizontal middl egrowing up.
The great thing about having a bunch of LEDs and a microcontroller is that you can experiment with lots of different display styles.
A lab partner of mine and I built one of these things in 1978. It was about 24 X 36 inches. The bulb spacing was about 0.75 inch and the front to back spacing was about an inch. We connected it to a 5 channel color organ and had a blast playing with it. We got some interesting effects by move the top or bottom closer to the back. Give it a shot. Good luck, Kim
How about doing a stereo design, but have each channel emanate from the far vertical sides towards the middle? You could also have the color start become more intense or brighten as it nears the middle. Low frequencies at the bottom and high frequencies at the top. You could generally correlate the sound spectrum with the breadth of the light spectrum - deep read to yellow, green, blue and purple for the highest audio frequencies with graduations bridging the gaps.
I actually saw that same vertical boombox with LED spectrum at the San Jose airport when I was leaving EE Live and I'm shocked it was $200! (Though, I am not shocked that the punk working there was too self absorbed to even make eye contact with you. Haha. Just so you know, I'm 27 and I still find that incredibly rude.) I'm glad to see someone move so swiftly from an idea to a project. It seems to take forever before my projects get any traction. But I'm eager to see what hardware will be involved in whatever project you settle on. My guess is 128 RGB LEDs, 2 Arduino Uno's, and 12 motorized potentiometers with aged-bronze dials.