Sound-activated EL wire inverters that you can buy only turn the EL wire on or off when they detect sound. I wanted to light up many different colors, each at a different volume level. I did this by taking the inverter that comes with those sound-activated equalizer t-shirts and using it to light up EL wire instead. I connected five different colors of EL wire to the inverter: green, blue, yellow, white, and red. When the music is quiet but not silent only the green wire lights up, a little louder and the green and blue light up, louder still and green, blue, and yellow light up, and so on until all five colors are lit. It's a very simple hack, but a great way to add more animation to your EL wire decorations. Note that this inverter probably won't drive long lengths of EL wire very well, so this idea is better applied to smaller pieces of EL wire art. I drove five pieces of wire each four feet long with out a problem.
Here's a link to an in-depth description of this idea with a couple of example projects.
Please share this idea with your friends. I think it's a cool idea and want more people to know about it and use it to create animated art.
