The Science Behind the Sounds:
The three main components the headphones are the voice coil, the neodymium magnets, and the diaphragm (the plastic cups). The voice coil is what causes the waves to be produced. We chose to do 30 coils because we tested 10, 20, and 30, and found that 30 worked best. The more coils, the better sound quality. If you would like to do more, you can. The music source creates an electrical current. This current travels to one end of the voice coil, then back. As the current switches directions, each end of the wire changes polarity. This is where the magnets come into play. The neodymium magnets create a permanent magnetic field, that helps the voice coil move. So as the polarity on either end of the voice coil change, those charges react to the permanent magnetic field. Meaning, one end repels the magnet, and the other is attracted. This causes the voice coil to move, because one side attracted down towards the magnet, and the other repelled away from the magnet. These vibrations compress air particles together and spread them out, creating longitudinal waves that transfer energy. We chose three magnets, because we found that the more magnets included, the stronger the magnetic field. This meant that the sound would be louder and clearer. Again, if you want to include more, you can. The cup acts as the diaphragm. The diaphragm is what directs those sound waves into your ears so that you can hear the music.
Make sure that your voice coil has room to vibrate. If it can't, no sound will be produced, so make sure that the decorations and/or the tape aren't holding or restricting the voice coils from vibrating. Also, make sure that none of the sanded wire touches, or else the electricity won't be able to travel correctly. If all else fails, rotate the AUX cord around to find the best position until you are able to hear sound.
Step 1: Gather Materials
One roll of electrical tape
Five meters of copper wire
A pair of scissors
Two plastic cups
Six neodymium magnets with a 1 centimeter diameter
One sheet of sandpaper
A regular-sized sticky note
Phone (or other electrical device to play music with)
Note: These can all be found at Michael's, Amazon, Fry's, and any other electronic store