Introduction: Post Apocalyptic Laser Light Show

You have seen videos with bits of mirror stuck to balloons making wonderful reflected patterns on the wall before the laser blows up the balloon? This INSTRUCTABLE takes it up to another level, with STEREO !


(1) Amplified speaker pair, the cheaper the better. They can be an old pair of PC speakers, bluetooth if you want to get fancy and wireless.

(1) bamboo skewer

(1) triangular chip off a broken mirror

Some hot melt glue if you excited to see this thing or silicone if you can spare the time.

(1) Laser, the more powerful the better.

Step 1: Just Five Easy Steps !

1. Cut away the speaker cones, keeping the center coil dust covers. This is to protect your ears from that awful sound they used to make . Besides, adding skewers and mirrors on them is not going to help them get any better ;-) Glue both speakers together.

2. Break or grind your mirror chip into a nice little isosceles triangle, 20mm tall by 20mm wide, or a little bigger if your laser is powerful and your aim is not that good ;-) The smaller the mirror, and the closer together the attachment points, the more wide the beam can spread and reactive it can be.

4. Cut three pieces of you bamboo skewer to the length between both speaker centers. Glue the end of one to the back side of the mirror and as as the glue sets, pull back on it to stretch it to create a hinge point as shown. This of course is to allow the mirror to pivot and send your laser beam all over the place.

5. Glue the other ends of the skewers to the center dust covers of your ex-speaker cones and glue the center one C to the crack between the two speakers. Depending where you want to fire your laser, level towards a wall, or upwards to the ceiling or the clouds, you can tilt the mirror accordingly.

Voilà ! Are you ready?

Step 2: Fire It Up!

Connect the speakers to a sound source.

Set up your laser so that it fires at the center of your mirror. Before turning on your laser, think of where it may reflect to as the mirror pivots. Always protect your eyes and those of others. If you are doing this outdoors at night, make sure there are no pilots in the sky. If there are regulations in your district, you should respect them.

Turn up the sound, turn on your laser, and watch the dot dance to the beat.

When the speakers push in phase, the dot goes up, when they are not in phase, the dot pattern widens. The gyrating forms and oscillations are fascinating due to the complexities of the resonances of the mirror, the push-rods, the ex-speakers and the entire system.