The Do It Yourself Laser Light Show has more to do with optics than electronics. Taping a mirror to your sub-woofer and pointing a laser at it is fairly ingenious. At least I never considered it, and I am nuts about lasers.

Most coverage of this project is useless. However, Kenwardtown does an amazing job explaining the mod with detailed pictures. “I recommend you don’t tape anything to the cone itself, because you can damage the cone.”