- A spool of 28 AWG wire (Use 9 meters)
- Available at Home Depot
- A roll of electrical tape (You will need A LOT)
- Available at Home Depot
- 2 plastic (preferably) containers for the headphones (to cover your ears)
- Be sure they fit you and that the plastic isn't too thick
- The vibrations created by the voice coil and magnet will have a harder time traveling if the plastic is thicker
- Can probably buy inexpensive containers (99 cent store or Daiso), or use recyclable material
- Available at Home Depot or Lowe's
- You can also use pliers that have a sharp edge.
- Available at Home Depot or Lowe's
- You can buy scissors anywhere in the world : )
- Make sure that there is no wire attached to the AUX plug because you will wire it yourself.
Step 1: Creating the Voice Coil
- Take your glue stick and some regular scotch tape.
- Wrap the tape around the glue stick loosely. Make sure that the sticky side is facing towards you. You will need to take two 4-inch strips of tape and make sure that they overlap when you put them on.
- Then, decide on how many coils you want to have in your headphones. Generally, the more coils you have, the better and louder the sound will be.
- For this project, we will just use thirty coils. Making sure that you don't wrap the wire too tightly around the tape, but check to see if you are coiling the wire neatly and not too loose.
Step 2: Finishing the Voice Coil and Sanding the Wire
- Once you have finished coiling the wire around the glue stick, pull off approximately two inches off each end of the wire. (We're doing this so we can connect the wire to the AUX plug.)
- Then, carefully and slowly, slide the tape (which still has the coiled wire on it) off the glue stick.
- After you've removed the tape and wire, peel the tape off the inside of the coil. BE CAREFUL!
- Tape the coils together to keep them secure.
- Then, sand off about 1.5 to 2 inches of the ends of the wire. When sanding, you know that you are done when you cannot see the red coating of the wire, and you see the copper instead.
Step 3: Assembling the Speaker
- Take one of your containers and place it upside-down.
- Then place a magnet on the top outside of the container.
- After that, take your other magnet and put it on the bottom of the inside of the cup. (Be sure that you put the magnets in a way that they will attract, not repel each other.)
- Place the coil of wire over the magnet that is on the top outside of the container. Make sure that you can still see your magnet through the center of your voice coil. (Your container should still be upside-down at this point.)
- Then secure your voice coil with two pieces of electrical tape (about four inches each piece).
- After securing the coil with tape, you should still be able to access the two sanded ends of the wire.
Step 4: Connecting the Speaker to the AUX Plug
- If you haven't done so already, take off the black casing of the AUX plug by twisting it.
- Take one of the ends of the sanded wire and loop it through one of the terminals in the AUX plug.
- Repeat step 2 for the other wire.
- If you want to be sure that the connection between your speaker and AUX plug is strong, you can solder them together. (Usually won't be necessary.)
- At this point, you have one functioning speaker, or half a pair of headphones. Good job! : )
- Take the device that has your music, and take the AUX plug from your speaker and plug it in the appropriate port.
- Select a song, and raise the speaker to your ear. If you hear something, GREAT!
- If you DO NOT hear any sound, go to the next step and we'll help you troubleshoot.
Step 5: Troubleshooting Your Speaker
- If you cannot hear any sound for some reason, check the connection between your speaker's wire and the AUX plug.
- If the connection with the AUX plug is not secure, twist the ends of the wires to make the connection tighter.
- If you still cannot hear sound, sand the ends of the wires again and solder them to the AUX plug.
- IF YOU STILL CANNOT HEAR ANY SOUND, you may want to check your coils to see if they are falling apart or not tight. If that is so, you have to re-do the coil. : )
Step 6: Completing Your Headphones
First, follow steps one through three to create your second speaker.
- Once you've finished, take one of the sanded edges of your new speaker and loop it into the second terminal of the AUX plug.
- Next, take your soldering iron and heat it up until it reaches approximately seven-hundred degrees Fahrenheit.
- Take the remaining ends of the two speakers that are not connected into the AUX plug, and twist them together.
- After you've twisted them together, cut off about an inch of tin solder and twist it around the wire you just twisted.
- PLEASE BE CAREFUL AND TAKE CAUTION WITH THE NEXT STEP!!! ADULT SUPERVISION IS NECESSARY IF YOU ARE A CHILD OR IF YOU HAVE NO EXPERIENCE WITH SOLDERING!!
- Next, with caution, solder the two ends of wire together by touching the iron to the tin solder. Eventually, after a few seconds, the solder will melt and solder the two ends of wire together.
- Now, you have a complete connection, and in theory, your headphones should be fully functional at this point! Yay!!
Step 7: Making It Look Nice!
Now that your headphones work, you can do whatever you want with it. Do whatever you desire. Use whatever you want to use to decorate your wonderful creation! It's recommended that you don't leave any wires or magnets exposed because it just doesn't look very nice. : (
The only decoration that I really did was include a logo on the containers and cover them with black electrical tape.
Step 8: Information About the Speaker
What are some important parts of the speaker?
- The Magnet - Provides a magnetic field
- The Voice Coil - Improves the magnetic field that is generated by the magnet; Provides a path for the electrical current
- The Diaphragm - Amplifies the vibrations that are created by the voice coil
What causes the voice coils to vibrate?
If you have any current that is going through any wire, it will become magnetic. That is what happens to the voice coil in a speaker. When there is an alternating current, meaning that the current is reversed, the polarity of the magnetic field in the speaker is reversed as well. So if the current is alternating direction, the polarity of the voice coil is going to flip back and forth. This action will cause the voice coil, which is magnetic, to attract and repel away and towards the neodymium magnet. The constant attracting and repelling of the voice coils are the ultimate source of the vibration. When opposite sides face each other, they will attract one another. So in the voice coil, when the two fields attract one another, the voice coil is pulled inwards, which causes the diaphragm to be pulled in. When the same sides face each other, they will repel one another. So again, in a voice coil, when the two fields repel one another, the voice coil is pushed outwards, which causes the diaphragm to be pushed outwards. These vibrations of the voice coil are actually the sounds that we hear when we use headphones or speakers. This is because there is acoustical energy traveling through a medium, which in this case, is the air. Sound always needs a medium in order to travel, so if you took your headphones to outer space, you would not be able to hear anything. This happens because in space, there is no medium for which the sound waves can travel through.
How to decide on the number of coils to use
When prototyping my headphones, my partner and I experimented with different numbers of coils to use. We tried to use ten, fifteen, twenty, and thirty coils. When we used ten coils, the amplitude of the sound was very short and so we could hear barely anything. So we believed that by increasing the number of coils in the speaker, we could get louder sound. After a lot of testing, we decided to use thirty coils because all the other number of coils didn't give us a strong enough of a sound. We also didn't want to spend too much time creating a higher number than thirty coils. However, generally, it is better to use more coils in your speaker if you want to generate a louder sound.