How to Make a Working Speaker From a Disposable Plate

Back in 2007, user HouseholdHacker posted a video on YouTube about how to build a high-quality speaker for under a dollar. Mythbusters took up the challenge and debunked the video's proposed method. And while it certainly doesn't seem to work, that doesn't mean it's impossible to build your own speaker for under a dollar. It's definitely possible—and quite easy. To learn how, watch the video at the end of this article.

To understand how the speaker works, I took it apart.

In its simplest form, it consists of a coil of wire glued to a piece of paper and placed near a permanent magnet. When alternating current passes through the wire in the coil, it is either attracted or repelled by the permanent magnet.

The audio signal from your stereo system is a unique form of alternating current. Let's connect it to a coil and place it near a stable magnetic field: changes in polarity and amplitude will cause the coil to vibrate thousands and thousands of times per second.

If this coil is connected to a diaphragm, the vibrations will move large volumes of air and generate the sound waves we hear.

In the images above, you can see the paper cone, the yellow centering washer (which holds the voice coil over the magnet), the voice coil with the magnetic wire wound around it, and the powerful permanent magnet at the bottom of the unit. The two ends of the coil wire are what connect to your stereo system.

That's it! Now let's see if we can make it ourselves!

For this we will need:

- disposable plastic bowl (for the speaker basket) - 8 cents

– disposable paper plate (placed on top of bowl to act as diffuser cone) – 5 cents

– button magnets (which can be used to make a cylinder) – 66 cents for six pieces

– a sheet of printer paper (voice coil stand) – 1 cent

– magnetic wire (for voice coil) – free

Magnetic wire is a thin enameled copper wire that can be found inside almost any electronic device, or, at worst, purchased at an electronics store.

You'll also need a hot glue gun and scissors, which you probably already have at home.

Not taking into account the fact that all these things are not sold individually, the cost of our speaker will be approximately 80 cents!

I found magnetic wire in an old TV. It was used to connect many of the small transformers on its circuit board.

aution: Do not disassemble your TV without proper training. The capacitors may become charged and could cause an electric shock.

Our 80-cent speaker is guaranteed to work! Sure, its quality matches the price, but it still sounds good—and that's what matters!

Stack 5-6 button magnets together to form a 1-2 inch cylinder. Then cut another strip of paper and do the same on top of the first strip.

Note: The two strips of paper should not be tightly pressed together. Instead, they should slide freely. The inner layer serves as a spacer, so that when we remove it, a small gap will form between the second layer and the magnets.

Wrap the wire around our cylinder about 50 times. It should hold tightly, but don't overdo it. Then, secure the wound wire in place with hot glue. Remove the magnets with the inner paper layer from the cylinder—you'll now have an empty paper tube wrapped in copper wire. This is your voice coil.

Cut it so that it can slide over the cylinder of magnets. Glue the voice coil to the bottom of the paper plate.

While the glue is drying, begin cutting out the outline of your speaker from the plastic bowl.

Then glue the magnets to the speaker. Once the glue has dried, hold the plate with the voice coil close to the magnets.

Place the plate with the coil on top of the magnets and secure it with glue.

I painted my speaker black to make it look more solid.

Remove the top layer from the ends of the copper wire. You can use sandpaper or fire to remove the enamel.