The Rubens' Tube: Soundwaves in Fire!

Step 6 A Note on the Sound Source

For this project, any sound source should work. I used my iPod with the driver from old 3 computer speakers I got from Goodwill. But nearly anything should work, from a do-it-yourself setup, to an old radio, to a hi-fi sound system, to a boom-box. In keeping with the Amazon spirit - I'd imagine most of these would get the job done, provided they require an external power source.

I also, have three recommendations.
1 - Whatever speaker you use should be able to reach volumes to move the diaphragm.
2 - The speaker should be placed or mounted close enough to the diaphragm to easily move it, without making physical contact
3 - The speaker's diameter should be as close as possible to the tube's diameter to ensure maximum diaphragm movement.

We're even lucky enough here in the Instructables community to have projects that would work wonderfully as a source of sound with little to no modification.

If you're interested in getting your hands on sine wave audio tones, they can be had by Googling for "Audio Test CD" or "Audio Test Tones". The one I used for this project was found here.

The image below shows the basic components of the business end of my setup.

Obviously, depending upon what you use to push sound into your tube, your mounting methods will vary, if you use a speaker that's still in it's housing, in all likelihood, you should be able to simply move the speaker close to the diaphragm. I've attached an image of my setup for reference, clearly not the most elegant solution, but it got the job done.