You might think that visualizing music with lasers would be a complicated and difficult affair. In fact, it’s remarkably simple if you want it to be, and [byte_thrasher] shows us just how easy it can be.
At heart, what you’re trying to do is make a laser trace out waveforms of the music you’re listening to, right? So you just need a way to move the laser’s beam along with the sound waves from whatever you’re listening to. You might be thinking about putting a laser on the head of a servo-operated platform fed movement instructions from a digital music file, but you’d be way over-complicating things. You already have something that moves with the music you play — a speaker!
[byte_thrasher’s] concept is simple. Get a Bluetooth speaker, and stick it in a bowl. Cover the bowl with a flexible membrane, like plastic wrap. Stick a small piece of mirror on the plastic. When you play music with the speaker, the mirror will vibrate and move in turn. All you then have to do is aim a safe laser in a safe direction such that it bounces off the mirror and projects on to a surface. Then, the laser will dance with your tunes, and it’ll probably look pretty cool!
We’ve seen some beautiful laser visual effects before, too. Just be careful and keep your power levels safe and your beams pointing where they should be.
put a bluetooth speaker in a bowl, cover the bowl with plastic wrap pulled taut, glue a shard of mirror to the plastic wrap, point a laser beam at the mirror so that it bounces off towards the ceiling, play music, enjoy pic.twitter.com/Vs6lBJihCg
— avi (@byte_thrasher) November 9, 2024
I remember this was all the rage back in the late 80s when HeNe lasers first started getting to be somewhat available. Every time there was a science demonstration showing off the power of lasers, something like this would always be a part of it. Usually it’d be even simpler, generally a mirror attached directly to the speaker cone via double-sided tape or the like.
This sounds a better for sound quality but perhaps less distinct movement in the laser? Maybe if the mirror was curved to employer the deflection of the laser? Convex I mean.
A little bit of tin foil (/aluminium foil/kitchen foil) stuck on an old speaker would be the simplest way, and the dome in the centre of the speaker would give you a handy convex surface.
JBL speakers already have plastic cone center. Maybe they could just integrate small mirror into it without having to change overal driven mass. Would be cool feature to add.
This reminds me of a Chladni plate.
Very fun and creative experiment. Thanks for sharing.
When I was a kid we would stretch a balloon across one end of a coffee can and glue a small piece of mirror to that rubber diaphragm. On a sunny day, talking or singing into the other end of the can allowed the sun to project a moving trace onto a dark wall. No lasers and no electronics.
Wow just comparing the peak of stimulation being this coffee can disco light to Fortnite is crazy.
People wonder why generations struggle to relate but we might as well be living in different worlds.
I tried this and my 10W diode laser keeps cutting through the mirror. It’s a bit disappointing because the light bulbs in my room are 8W and I want the spot to be visible even with them on.
I suggest you get a better mirror, and a more powerful laser
Thanks. A friend has a 50W CO2 tube but he said that the dot is really faint, even when you stare into the beam, so it might be defective, though he has had vision troubles lately.
Do not Stare into the Lazer with your Remaining good Eye..
There’s a far easier way. Just stick the mirror onto the speaker cone. Done. (I’ve been doing that since the days of HeNe lasers)
Attach one edge of the mirror to the speaker cone, and the opposite edge to an arm affixed to the frame, and you now have adjustable deflection amplitude through volume control in X axis. Now, deflect off second speaker with the same assembly, mounted with the mirror travel perpendicular to the first, and you have Y axis for 2D patterns. Bonus if speaker channels are stereo left and right, to control X,Y ratio with balance. 1st mirror should be only big enough to contain the beam within it’s transit. 2nd mirror will need to be wider to contain the deflection of the 1st. Mount the speakers as close together, with as acute an angle as possible without blocking the beam. This was my setup with He/Ne back in the day, but the speakers were actually nothing more than 1 cm voice coils, so they could be cranked up as far as your light output could still be visible, while the separate, audible speakers could be kept at reasonable levels. Acoustic guitar recordings can make for some remarkable patterns, but you’ll definitely also be tempted by Jean Luc Jarre, or something of that nature. Smoke or vapor for interesting swirling cross section effects, but take it easy. You’ll want still air, and lack of ventilation can lead to other….effects…..
Ask me how I know.
Warning! Do attempt this if you have pending deadlines! You WILL be mesmerized for long periods!
And of course, do not look into the beam with remaining eye!
Can you explain this in a different way? Seems pretty interesting but i am not quite geting this setup. thanks in advance
Using bluetooth may introduce enough lag to spoil the beat bouncing in time with the source unless the single speaker is all there is to hear. Some bluetooth devices can only feed or receive only 1 thing at a time. Try gluing a long sliver of mirror with a dab of silicone rubber to the dome and beyond the rim with a standoff that is stationary. Best to do to cheap soda can sized “woofers”. This will make angular motions to the beam, for a bigger scene. Don’t forget hard drive head position galvos, more fun to be had.
I glomed onto a gutted LaserDisc He-Ne and it’s x/y galvos, makes for a great show.
Edmund Scientific, back when they were a surplus optics and random science and technological wierdities, sold a fair amount of light show hardware. One of their cheap widgets was essentially this with a bit of refinement. First-surface mirrors produce sharper images. Different effects can be obtained by altering how the mirror is attached to the rubber membrane — from small standoffs to increase amplitude of the resonance Lissajous figures and adjust their shape to fit the needs of the space to hanging the mirror by a string for really wild bounces and streaks of light. Their manufactured version let you interchange membranes to change effect sets; the experimenter version just glued the membrane to the speaker and you would swap the entire device to change patterns.
Still have mine. Keep thinking about setting up a semipermanent installation in the living room…
And Edmund called it “MusicVision”. I was haunting their store in those days.
If you still have yours, surely you have replaced that membrane at least once? Mine dried out and disintegrated after maybe five years, but Edmund still sold large pieces of the membrane so I boutght a prertty big piece and kept it in a sealed bag until I’d used it all up. BTW, those thin, little first-surface mirrors are devilishly hard to get these days. Edmund long ago stopped selling something comparable, and I haven’t been able to come up with a suitable search term for AliExpress.