Make a homemade speaker using paper plates, a magnet, paper and magnet wire. A strong magnet, such as a neodynium magnet, works best, as it forces the speaker coil and diaphragm to move more. The magnet wire and paper form the voice coil, while the paper plates act as supports and the speaker cone.
Wrap two layers of paper around the magnet, then wrap the wire around the paper to make a tight coil. Around 50 wraps of wire is sufficient. Leave two ends of wire protruding, as these are used to connect to the sound source. Hot glue the wire to the paper and cut the paper to size, so that it is shorter than the magnet. When an alternating current flows through the coil, the magnet attracts and repels it thousands of times a second. Attaching a plate to the coil creates a diaphragm, which moves more air and generates sound waves.
Hot glue the coil to the center of the back of a paper plate. Glue the magnet to the second paper plate, and add two accordion-style cardboard supports. These supports hold the diaphragm in place while allowing it to move up and down.
Slide the coil over the magnet, and glue the top plate to the supports. Strip the very end of the coating off the copper wire, and connect the speaker to a TV or stereo using alligator clips.