Step 1: Materials
(Photos of materials in order as listed below)
Tools and Materials List:
- 28 Gauge Copper Wire (2x 3 arms length)
- Expo Marker
- 2 Paper Cups
- 2 , 3.5 mm Stereo Jacks
- 8 total neodymium magnets (diameter = .75)
- 1 piece of Sandpaper
- 1 Wire Cutter
- Electrical Tape
- Solder Iron
- Solder Metal wire
Step 2: Assembly, Sanding, and Coiling
- First you start off by gathering all the materials listed above
- Then you start by getting the 28 Gauge Copper and wrapping it tightly around the expo marker 75 times, leaving about 15 centimeters of wire on each side to create the voice coil (Make sure to count how many times you are wrapping it around the expo marker)
- We chose to coil it 75 times because we found that 75 wraps sounded clear and loud compared to less wraps. The reason we coil the wire is so that it can act as an electromagnet, and by running electric current through the wire, it strengthens the magnetic field. During this process the voice coil becomes a temporary magnet. The voice coil becomes magnetic because of the electrical current that is flowing through. It is temporary because when there is no longer electric current flowing through, it is no longer magnetic.
- We chose to coil the wire 75 times because we saw when testing different number of coils, the more you coil the wire, the stronger magnetic field there will be (If you have wire left over, then you can wrap it around more times to get better results).
- The reason we sand both ends of the wire is because the red enamel on the gauge wire is an insulator, meaning that it does not conduct electricity., We sand both loose ends of the wire to take off the red enamel so that when we put them together, the electricity is able to flow through.
Step 3: Step 3: Magnet Positioning and Diaphragm Assembly
- Next you are going to start by getting the paper cup and 4 neodymium magnets
- You are going to put two magnets on the inside of the paper cup and the other two on the outside. They should be at the bottom of the cup; They should connect
- The magnets act as the permanent magnets. We need a permanent magnet because the permanent magnet is what attracts and pushes sound from the voice coil. We chose 4 big neodymium magnets because, the more magnets there are, there will be a stronger magnetic field. Also, the reason we chose the paper cup was because it provided the best sound. The plastic cup sounded very staticy and the foam cup’s sound was very low and not clear. The paper cup acts a diaphragm which is needed to to amplify the vibrations and send the sound waves in different directions
- Next, you are going to put the voice coil on the magnet that is outside the cup. Put it so that the magnet is in the center of the voice coil
- The permanent magnet should be in the center so that it can attract and repel to the voice coil. When the voice coil becomes magnetized, the permanent magnet in the center becomes north and the voice coil becomes south. They then alternate creating vibrations
- Then you grab a piece of electrical tape and place it on top the voice coil and magnet to help keep everything in place
Step 4: Step 4: Plug and Play
- Next you are going to repeat all steps listed above to create the other half of the headphones
- Once you have both baskets, you are going to get one loose end of both the coils and wrap them together tightly. Make sure both ends were sanded thoroughly
- The reason we sand the wires is to take off the red enamel on the wires. The red enamel is an insulator meaning that it does not conduct electricity.
- Next, you are going to get the other other loose ends of the coil from both baskets and put them through the terminals of the AUX plug. Also make sure that the coil is sanded
- You have to sand the other loose ends of the coil because this will allow the electric current to flow through the wire and into the terminals, which is metal.
- When putting the wire on the terminals, tie them tightly so that they do not come out and it is important that they do not touch
- Next if you have access to metal wire and a solder, then melt metal onto the coiled wires where it is sanded where the wires connect and where the terminals are. We do this because metal is a better conductor of electricity, so the music will sound louder and clearer
- Lastly, you plug the AUX into your mobile device and play music
- As a result, sound waves are produced when the voice coil vibrates. The permanent magnet attracts and pushes sound from and to the voice coil or the temporary magnet. With electric current running through it, the voice coil strengthens the magnetic field because of the coiled wire. The electric current switches back and forth, also called an alternating current, which causes the voice coil to vibrate and then produce sound waves, which then go to the diaphragm. The alternating current is important because without it, the voice coil would not vibrate. If the current would just go in one direction there would be no sound waves because it wouldn’t vibrate. The diaphragm, or paper cup, helps amplify the sound waves from the voice coil and send them in different directions
- When listening to the music through the headphones, you notice that on each headphone, there are different sounds. On one headphone the lyrics are low and unclear, but the bass and the high pitches are very loud and clear. On the other headphone, the lyrics are very clear and you can’t really hear the background sounds. When you put both headphones to your ear the quality of all sounds become clear and loud.
Step 5: Step 5: Troubleshooting
If you happen not to hear sound through your headphones, here are some ways that you can improve/ modify/change so that you are able to hear sound:
- Sand the loose ends of the coil more thoroughly where both wires connect
- Sand the loose ends of the coil more thoroughly where wires connect to the terminals
- Make sure that wires are not touching where the terminals are
- Make sure the magnet is at the center of the voice coil
- Coil the wire more times
- Coil the wire more tightly
- Add more neodymium magnets (diameter = .75)
- Change material of diaphragm. Either to plastic or foam
- Make sure the there is volume on your mobile device
- Make sure you have a magnet on the inside of the cup and outside