Beats by Katie & Stephanie

Magnet: A permanent magnet creates the current to attract or repel the voice coil by alternating the current. The alternating current causes the voice coil to be attracted and repelled which creates vibrations. The vibrations move the diaphragm and then produce sound. The magnet creates the permanent electromagnetic field that the voice coil needs to be in to produce sound. The permanent magnet needs to be in the center of the diaphragm to create even vibrations throughout the circular diaphragm.

Diaphragm: The diaphragm is a soft,cloth-like, material that vibrates when sound waves are pushed at it. It sits right above the voice coil and different types of vibrations correlate to different sound that is produced.

Voice coil: This is what creates the sound by being attracted and repelled by the permanent magnet. It is also the temporary magnet. It becomes an electromagnet after current flows through the speaker. The voice coil also directs the current out of the speaker to produces sound and vibrate the diaphragm. In order to move the current, the voice coil must be made out of conductive material. It is usually made of tightly coiled copper wire.

• 1 wire cutter
  • Can be purchased at any hardware store Strong scissors or anything that can cut wire will work as a replacement
• About 4.50 meters of 28-36 AWG copper wire
  • More wire allows you to make more coils for louder and higher quality sound
  • You need about 2.25 meters of wire for each voice coil
  • Can be purchased at any hardware store
• Few inches of electrical tape (optional)
  • We did not use any electrical tape, but we observed that using it may help hold certain parts of the headphones in place.
  • Not necessary, only use if your voice coil will not stay in place
  • Can be purchased at any hardware store
• One small piece of sandpaper
  • The grit strength does not matter
  • Can be a small piece, it is only used to lightly sand wire
  • Can be purchased at any hardware store
• 1 AUX cord connector (wire part is not necessary)
  • Found at electronics stores Radio Shack, Fry’s Electronics, etc.
  • At least 3 neodymium magnets 2 different diameters
  • One should be around 1 centimeter, the others should be anything smaller than the large one.
  • We used .5 centimeter diameter for the small magnets.
  • Have at least 2 small magnets, 1 or more large magnets
  • Can be purchased online or at electronics stores
• 1 audio source
  • A phone, computer, or iPod will work as an audio source
• 2 plastic cups
  • We tested many materials and found that the plastic cup creates the loudest sound due to it being light and it can easily vibrate
• Small cup, about 3 inches tall
  • Paper and styrofoam cups work, too
• 1 pencil
  • Used while coiling the wires
  • Can be replaced by any long narrow tube-like item.
  • The tube we used to coil the wire had a diameter of 1 centimeter

Materials you need for this step:

• Sandpaper
• 28 AWG wire

1. Cut a piece of sandpaper into a small piece
   1. It just needs to be comfortable to hold while sanding small, thin wire
2. Measure 5-7 centimeters on both ends of the wire
3. Sand both ends of the wire
4. Make sure all of the enamel is removed from the ends

The wire must be sanded because the enamel will block the current from flowing to the speakers. Removing the enamel allows the wires to directly touch the AUX plug terminals. The enamel is an insulator because it allows the wires to be safely handled without being electrocuted. Be careful not to let the two sanded parts of the wires touch, this may cause problems with the sound reaching the speakers.

The wire needs to be in a tight coil because when the magnet alternates it’s current it will be able to send an even wave through the voice coil, which will allow the diaphragm to vibrate the most. The waves will be larger when it is coiled because every wire will be pushing against each other in the same direction, all trying to produce the largest wave. The voice coil is a conductor because it carries the current and electricity through the headphones to vibrate the diaphragm.

You will need the following materials for this step: Wire cutters (or your wire,if you already cut it) Or your wire, if you already cut it Neodymium magnets Pencil or tube (diameter should be about 1 centimeter) Steps: The wire will be coiled around the pencil or tube While making our prototype, we found that it is easiest to coil the wire around an object. A tube, with a diameter of about 1 centimeter, was the perfect size and shape for our voice coil. Cut about 2.25 meters About 2.25 meters of wire for each voice coil. 4.5 total meters. Having more than this is good, it will allow you to add more coils to the voice coil or you can have longer ends that connect to the AUX plug. Leave at least 20 centimeters of wire on both ends. If you have more than 20 cm, you can have longer cord from your phone to connect to your speakers. Wrap the wire in tight coils around the pencil. Try not to make it too tight because you will need to slide it off the pencil. If it helps, put a post-it note or paper on the pencil and coil the wire over that so you can easily slide the paper off the pencil. Try to wrap it 40-55 times When creating our prototype, we tested many different amounts of coils. We found that more than about 70 coils did not produce any sound. Less than 30 coils was very quiet. It is easier to count while coiling instead of counting after you finish coiling Slide the coil off the pencil Wrap part of the ends around the coils. It should only take 1-2 wraps to keep the coil from disassembling The coil should now be ready to be attached to the diaphragm.

Materials to find:

Cups

Neodymium magnets

Your newly created voice coil

Steps: Place one of the small magnets on the inside of the cup

Put 1-3 small magnets on the outside of the cup

The voice coil will be put around the small magnets on the outside of the cup

To make sure the voice coil does not slide off, put a magnet with a large diameter on top of the small ones

Adding more magnets improves the sound volume

Positioning Materials: The speaker you have just made! Steps: If the magnets and voice coil isn’t centered on the cup/diaphragm, your speaker may not create any sound In commercial speakers, the voice coil is always perfectly centered and the diaphragm is round to allow for the best vibrations. The voice coil will evenly vibrate the diaphragm if it is in the center. To move the magnets and voice coil to the center, pull on the magnet on the inside of the cup. This is easier to move than the magnets covering the voice coil, since you don’t want to put too much pressure on the voice coil! The part on the outside of the cup will move due to the magnets being attracted to each other. Since the voice coil surrounds the magnets, the voice coil will also move when you move the magnets.

Materials: The speakers made in the previous steps

Aux plug

Uncover the terminals on the aux plug. (You should be able to do this by twisting off the casing)

Take the corresponding wires (red to red, green to green in the diagram) and attach each set to the one of the terminals on the aux plugIf your headphones do not work, try switching the wires that are attached. It should be one wire from each speaker, but you might have to swap them a few times to find the correct combination. You also might need to switch which wires are connected to which side of the aux plug.

After that:

Decorate as you like, but make sure that you do not touch the magnets on the outside of the cup to whatever covers them, because that will not allow the diaphragm to vibrate.