How to Make a Plate Speaker

Make a plate speaker from objects around the house. Start with a deep plate like the kind that risotto (an Italian rice dish) is served on. It should be almost deep enough to be considered a shallow bowl. Make sure that the magnet you use is the strongest that you can find and that the wire is the thinnest. The wire can be scavenged from the inside of a small motor. The magnet can come from a broken speaker or you can use a button magnet of the type commonly used to hold things onto the refrigerator.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Risotto-style plate
• Toilet-paper roll
• Wire (salvaged from a motor or two)
• Magnet (the more powerful the better but small enough to fit into a toilet paper tube)
• Hot glue and glue gun
• Wax paper
• Alligator clips (or a soldering iron with solder)
• Speaker jack, stripped at the end so there are two leads
• Sandpaper

1. Cut a toilet-paper roll in such a way that a 1/2-inch tall section from the cardboard tube is exposed when placed on end. Wrap the wire around the shortened section of cardboard at least 50 times. Leave a little wire from the start of the coil. It should stick out 2 inches past the edge of the plate. Save the end of the coil and send it out next to the other wire going into the coil. End it about an inch past the other end.

2. Glue the coil on the plate with a hot glue gun so that the coil is centered at the middle of the inner face of the plate. Use enough glue to keep the coil from falling apart. Then use the hot glue gun to attach leads (from the start and end of the coil) to the plate. Guide the leads out to the same spot at the edge of the plate so that they are as flat as possible against the edge.

3. Cut a piece of wax paper that fits over the top of the plate with an inch to spare on all sides. Crease the edges using the plate as a guide. Glue the magnet into the center of the wax paper circle that is creased to match the plate so that if the crease is superimposed over the edge of the plate the shortened toilet-paper roll will circle the magnet.

4. Use the hot glue gun to glue the wax paper onto the plate with the plate face down. Before the glue solidifies, make sure that the wax paper is pulled tightly so no wrinkles form. Wait for the glue to completely solidify.

5. Strip the ends of the wires sticking out from the side of the plate by sanding them with sandpaper to remove the coating. Use alligator clips to attach the speaker to the appropriate location. If you need a jack, make sure that it has two wire leads. They can be stripped and soldered to the ends of the wires coming from the speaker if you do not want to rely on the alligator clips. For help soldering, see our other "How-To" articles.

Tips & Warnings

• For best results, use a powerful and relatively light-weight magnet. Make sure that the wax paper is tight. The wire should be coiled as closely around the magnet as possible since a little distance makes a big difference with magnets. Also make sure that the turnings (wraps around the tube) are as plentiful as possible.
• Be careful with electricity and never get any parts of the speaker wet. Be careful with the hot glue gun and glue since it is hot and sticky. Do not let the paper get hot enough to catch fire while you are making this or operating it. Never leave the speaker plugged in when you are not present.

Resources

• Foam Plate Speaker: Makezine
• Popcan Headphone: Video
• Subwoofer Solenoid: Video
• Plastic Cup Speaker: Video