Ok, I read this interesting article in my latest copy of Make about how to make your own simple laser light show. My particular test device is acoustic based. In short it is real simple, just aim a laser pointer at 2 mirrors attached to the cones of speakers that are wired to your stereo. In my case to keep it real simple, I wired the speakers in parallel - they are both receiving the same signal. Other configurations could have the two speakers wired separately to the Left and Right signals. In practice I doubt this will make much of a difference.

Here's the basic block diagram layout:



I started by mounting my laser pointer. Since I'm just playing around with what it might produce I didn't take time to build a nice box or anything. I just used a vice grip (pliers) to hold the pointer's switch on and then stuck them in a bench vice.



This is shot across my shop to a pair of PC speakers being held in place temporarily by a helping-hand tool. The mirrors are front side coated. They are cut from a bar mirror that came out of a laser printer. I attached them to the speakers with 2 sided tape.



The end result is a neat laser pattern that changes and dances to the music. Bass beats cause the most dramatic effect, although simple voice (radio DJ) generates the most interesting patterns.



I made a couple of videos of the unit in action. As you can tell, the little speakers sound awful. A better setup would be mount the mirrors to the voice coil and remove the cones - this would make the system quieter. Than place in an insulated box with an opening just large enough for the light to escape.



The patterns are dimmer, but more impressive when shot 30 feet across my basement onto the far wall.