At least 30 cm of 28 AWG Copper Wire (2 sets of 15 cm wires)
2 (optional 4) plastic cups or bowls (diameter must match or slightly extend the diameter of your ear)
At least 2 small neodymium magnets (at least 2 cm in diameter)
3.5 mm audio jack
Long thin tube, like a pencil or marker
Colored construction paper (optional)
Soldering iron (optional)
Step 1: Creating the Coil
First off, the coil is probably the most delicate and important part of the headphones, so be very careful when making this particular part. Start by sanding off an inch of the insulating coating from the ends. This allows a place for electricity to run to and from the wire. In the middle of the wire start coiling it by running it around a pencil or marker. To make them loud enough, at least 30 coils and 2 magnets per cup is recommended to make a decent amount of sound. For only 2 magnets, 48 is a good amount of coils. Try not to overlap your coils in the coiling process.
Step 2: Diaphragm
Once you're finished with the coiling, put the magnets inside the coil. Place the coil and magnet against the bottom of the paper cup. Make sure it is in the middle of the cup, then tape it down. We chose paper cups rather than materials like plastic or Styrofoam because this cup gave us the louder and clearer sound than the other materials. If you have the 2 extra optional cups, place the second cup over the magnet and coil to hide and protect the parts. Tape the paper cups on.
Step 3: Auxiliary Jack
To test if the headphones work, just connect the sanded off parts of the wire to the little holes of the jack. Make sure that the unsanded parts of each end of the wire DON’T touch. This will cause the electric current to go through the intersection of the sanded wires rather than through the coil. If they work, knot them on the jack, so they they won’t slip off. If you have access to one, use a soldering iron to bind the wire and the pins of the jack together, which ends in an overall cleaner and easier connection experience.
Step 4: Extras
If you want to make your headphones look decent, use construction paper to hide the ugly colors and patterns of your cup. You can simply tape or glue it on the cup. For a headband, an old sturdy headband could work, simply by tapping the cups onto the band. However, if you don’t have a headband, fold a piece of construction paper so will act like a headband. To hide the ugly wires, wrap construction paper over the wires, which provides protection and gives a more acceptable (usually black) color rather than the ugly reddish color of the wire insulator. If you have it, shrink wrap tubing is a very good way to hide and protect the copper wire.
Step 5: Trouble Shooting
Troubleshooting and modification
If you cannot hear anything: Make sure the sanded parts of the wire are not touching each other Make sure the 3.5mm jack and the wire is touching properly Make sure the volume is high enough If the number of coils is below 30, chances are you won’t hear much If you want to further improve this design: More coils usually mean louder. With this, make sure there are enough permanent magnets to make use of them Try different coil and magnet diameters. Try larger magnets, and larger coils to fit them. Experiment with different cup materials, we already tested with Styrofoam, paper and standard plastic cups, but we found that paper was the best of the few. However, there are many different types of plastic, and each type may give a different quality of sound.