How to build headphones by Hannah and Kirtlynn
Step 1: Step 1: Materials
1. 2 small paper cups (any grocery store) 5 ½ inches
2. Foil ( for design : OPTIONAL ) ½ sheet ( sold at any grocery store)
3. Sand Paper ( sold at home Depot ) ¾ of a sheet.
4. 8 pieces of Electrical Tape ( Amazon, Home Depot )
5. 2- 4 inch pieces Wire cutter or regular scissors (Can be found in any craft store.)
6. 3.5 mm stereo jack (aux plug) (Amazon)
7. 28 AWG (American Wire Gauge) (Michael's, Home Depot, Amazon)
8. 6 Neodymium magnets (Home Depot or Amazon)
9. Ear Cushion for support (2) Can be bought on Amazon
10. Pliers ( Home Depot or Michael's )
11. A solder ( Home Depot )
12. A phone with an aux source (sold by Best Buy , Target, or any electronic store)
Step 2: Step 2:Assembly
1.Measure 3 feet of 28 AWG wire
2.Sand about 3 inches on both of the ends of the wire.
3.Take a sharpie and coil the wire around it 50 times (make sure not to coil the copper ends.)
4.Taking the coil of wire, thread both of the ends into the inside of the coil to secure it in place.
5.Taking your diaphragm (paper cup) place one magnet on the outside and two on the inside)
6.Taking the coil of wire, place it on the outside of the diaphragm where the first magnet was placed and secure it on top using 4 pieces of electrical tape.
7.Repeat this process once more so that you have two speakers.
8.Optional step: Take the foil sheet and wrap it around the paper cup and secure it using to tape to have better quality sound.
9.Optional step:Take an ear cushion and put it over the open paper cup for comfort. Now take one of the ends of the wire (copper end) from each speaker.
10.Take the copper ends and put them parallel to each other and wrap them together. To make the connection permanent solder them together by taking a soldering iron and metal and painting it on.
11.Take the last two copper ends and attach them through the holes of the terminals. Take a pair of pliers and turn the ends inwards in able to fit into the cap of the aux.
12.Solder the copper ends that are attached to the terminals by painting it on as you did in step 12. Take the aux and screw it into the cap,
13.Lastly, cover the bare wire with duct tape or electrical tape and start listening!
14.If you are having trouble listening to music follow the troubleshooting steps.
15.You may also refer to the following images to help guide you through the process.
Step 3: Step 3: Sanding and Coiling
You must sand 3-5 inches of each end of the wire because copper is a good conductor of electricity. The copper will conduct the electricity through the coils of wire when attached to a power source. Once you have sanded both ends of each wire be sure to coil it around a sharpie. When coiling be sure to leave of the copper ends because those will be later used. We found that coiling the wire around 50 times worked the best. We coil wire in order to create a stronger magnetic field and produce the best sound. When prototyping, we noticed that anything lower would give faint sounds, and anything higher would give a muffled sound. With the copper ends, wrap two around the terminals of the aux to have current flow through. When connected to a power source (a smart phone) the terminals on the aux will send current through the wire and allow the voice coil to vibrate in order to hear sound. You also must connect the ends on the other half of the wire to have both speakers work.
Right Hand Rule
The right hand rule uses your right hand to find the direction of the magnetic field around a wire based on the duration if the current. Your fingertips will represent the magnetic field, you're palm will represent the fore, and your thumb will represent the direction of the current. If the direction of the current is flowing to the left, then the magnetic field will be going over, around the wire. If the current is flowing to the right, then the magnetic field will be coming out from underneath the wire.
The Diaphragm and Magnet Assembly featuring the Voice Coil
The diaphragm we chose to use was a per cup. When prototyping, than projected the most clear sound. The purpose of a diaphragm is to produce and project the sound waves. The shape of the diaphragm is usually in a cone. The most common materials used are paper, plastic, or metal. The material should be flexible in order to vibrate rapidly. On top of the diaphragm is the voice coil. The voice is coil in our speaker was made from 28 AWG wire and coiled 50 times around a sharpie. The ends were then threaded inwards to secure it in place. The voice coil is what provides the main force to the diaphragm by reacting to the magnetic field provided by the permanent magnets. The permanent magnets are placed in the middle because it needs to provide a magnetic field around the voice coil so that the voice coil is able to vibrate and produce sound. The current then passes through it. The more coils you have wrapped tightly together, the stronger your magnetic field will be. Our voice coil has 50 coils.
Temporary and Permanent Magnets + Magnet Assembly
A temporary magnet is only temporary, of course. Once a switch is open the current will stop flowing and the magnetic field will no longer exist. A permanent magnet will always provide a magnetic field no matter what. They also do not come magnetized, but can be magnetized easily and can then magnetize other objects. We chose to use a total of six magnets for our headphones. We placed one in the middle of the voice coil above the diaphragm,and two underneath. We did this for both speaker to have a total of ix. While prototyping, we observed that this worked the best because only two seemed to barely work, but when we added an extra magnet the vibrations become stronger. Permanent magnets are placed in the center of the coil because it allows a magnetic field to be created around the voice coil in order for it to vibrate.
Step 4: Step 4: Plug and Play
You must sand the ends of the wire and connect them to the terminals in order for current to flow through. Copper is a great conductor of electricity and will allow current to flow through the voice coil. The terminals are on the aux plug, which is connected to a power source and thus allows the headphones to operate. The sound waves are produced when the voice coil vibrates. The alternating currents are important because this will allow the voice coil to vibrate. Because of the alternating currents, the electromagnets will attract and repel also causing the voice coil to vibrate.
Step 5: Step 5:Troubleshooting
If you are not hearing any sound it is because a piece is loose or tangled. To solve this problem gently check to make sure the ends of your wires, connected to the terminals, are not tangled or touching. Also, make sure the connection above your head is not tangled. Lastly, make sure the tape over the voice coil is not coming off or loose. Make sure it is tightly on, over the magnet. Make sure you have your volume all the way up to hear the best quality sound and have fun!