Step 2: $1 Paper Plate Speaker?
MythBusters took on the challenge and busted it.
Although that particular method doesn't seem to work, it doesn't mean you can't make your own speaker for under $1.
Actually you can, and it's really easy!
Watch this video to see how!
Step 3: How Does a Speaker Work?
In it's simplest form, a speaker is just a coil of wire glued to a piece of paper, and placed near a permanent magnet.
When alternating current flows through the coiled wire, it is either attracted, or repelled by the permanent magnet.
The audio signal from your stereo is a form of alternating current. When attached to a coil of wire and set near a stable magnetic field, the variations in polarity and amplitude will make it vibrate thousands upon thousands of times per second.
If this coiled wire is attached to a diaphragm, the vibrations will push a larger volume of air and generate sound waves that we can hear.
In the pictures above, you can see a paper speaker cone, the yellow spider (which holds the voice coil in place over the magnet), the voice coil with wrappings of magnet wire around it, and a strong permanent magnet at the bottom of the assembly.
The two ends of the voice coil wire are what connect to your stereo system.
That's all there is to it! Now let's see if we can make one!