The three main parts of headphones are the magnets, because they create the magnetic field, the diaphragm, and the voice coil, because that is what brings the vibrations through the headphones. Voice coils vibrate because you have current alternating in the wires, if the current switches directions, which makes it attract and repel from the magnets. These actions cause the voice coil to vibrate. When a voice coil vibrates, it would move all over, but when it is held down on the sides, it can only move up and down. Sound is heard when vibrations from an audio source vibrate back and fourth through a medium, making sound waves which travel to your ears and are processed by your ears. During prototyping, we tested number of coils, type of diaphragm, and material of cover on headphones. We found that the more coils you use, the louder and clearer the sound quality would be, so that is why we used 30 coils, rather than 10. When selecting your magnet, make sure it is a permanent magnet, like the neodymium ones we used. A permanent magnet has north and south poles, and keeps it's magnetism even after the magnetic field is gone.
Troubleshooting: If you are unable to hear sound from your speaker, here is a list of common mistakes made when building headphones.
-make sure the ends of all wires are sanded (no red coating left on the outside)
-make sure the voice coils are able to move, so they can vibrate
-the wires going into the aux plug should not be touching each other
Step 1: Gather Your Materials
Ruler (office supply store)
Wire cutters (hardware store)
About 84 inches of 28 gauge copper wire (Copper wire conducts electricity better than other types of wire) (craft or hardware store)
Glue stick with a diameter of about .75 inches (office supply store)
AUX plug (electronic store, like Fry's)
2 by 3in cardboard boxes (Best diaphragm we tested for clear and loud sound.) (craft store)
Two neodymium magnets (1 cm diameter) (electronic store)
Any color masking, duct, or painters tape (craft, office supply store)
Electrical tape (Easy to pull off of glue stick.) (hardware or electronic store)
Two regular magnets (electronic store)
Sand paper (hardware store)
Sticky notes (office store)
Take out electrical tape and glue stick. Put electrical tape around outside of glue stick with the sticky side facing out.
Place copper wire on the electrical tape and start coiling around the electrical tape in a circular motion. Do this until you have wrapped it around 30 times. After you've finished coiling, leave 2 5" pieces of coil on either side of the coil. (for only 1 side on ONE coil, leave 10", rather than 5)
-Coils with wire wrapped around thirty times work better than coils with wire wrapped around less times.
Sand about 3" off the ends of each coil until the red outer layer is not showing.
Gently remove the coil (with the electrical tape underneath) from the gluestick.
Repeat steps 2-6 for a second coil.
Place a voice coil in the center of the cardboard box (on the outside) and put a magnet in the center of the voice coil. Place another magnet on the inside of the box. (make sure the voice coil is touching the box, if it is not, it will not vibrate and create sound)
Place tape in an "X" shape over the voice coil on the front of the box. Make sure the sanded 3" pieces are not taped down.
Repeat steps 8-9 with the other box and voice coil.
Take the 10" end of the coil wire and wrap it around the headband. Once that is finished, twist the end piece to one of the 5" pieces (on the other voice coil).
Take the plastic cover off the aux plug. There should be two little bar-like “prongs" with two small holes in them. Connect the 5" wire hanging off of one of the voice coils to one of the holes. Connect the end of the other 5" wire hanging off of the other voice coil, and connect it to the second hole.
Step 12: (Optional Step.)
Cover wires with any color tape, tape around rest of headphones if you would like the boxes and headband to be covered.
Connect AUX plug to music playing device such as a smartphone.
If sound is not heard through headphones when music is on full volume and phone is plugged in, try moving the wires around the AUX plug and make sure neither wires are touching.