2 neodymium magnets
1 plastic cup
3 Most Important components
The three most important components in any speaker/headphone are the magnets, voice coil, and the diaphragm. The magnets are important because it provides a magnetic field and attracts and repels with the voice coil. The voice coil is also important because it makes the magnetic field stronger and provides a path for the electric current to flow through. The diaphragm is important because it amplifies the vibrations which is caused by the voice coils, to push sound waves outwards.
Our results with this project
The voice coil has an affect on the loudness of the sound being made. For example, we found out that the voice coil had to be tightly wrapped and it had to be directly on the cup in order for the sound to be clear and loud. We also noticed that the aux cord had an affect on sound. for example, we had to move around the wire attached to the aux cord and see which direction had the best connection. We found that pulling the wire tightly makes the sound louder and clearer.
Step 1: Gather Materials
Watch this video to see pictures of the actual items^
2 neodymium magnets
1 plastic cup AUX cord
Step 2: Assembling Voice Coil
Once you collected the proper amount of wire, you can now create the coil. To do this, you can use any cylinder-shaped object. We would recommend using a glue stick or any type of marker. Now you can start wrapping the wire around the object, making sure to not overlap the wire or else it would be hard to separate. Don't forget to count each time you wrap the coil around the marker/glue stick (40 works best). Once you've finished, carefully pull the wire off of the object. It should look like a slinky. Next, you will now want to push inwards carefully to gather all of the coils to look like one big coil (it will have 40 coils but it will be stuck together.) After this, you will want to take one end of the coil and wrap it around all 40 coils, and repeat this for the other end of the coil. Watch video provided for extra help.
Why do voice coils vibrate?
Passing current through the coil creates a magnetic field. When the current is reversed it switches the polarity. Due to the permanent magnet in our headphone and the magnetic field of the coil, the too like fields repel one another which allows the coil to move outwards. When the magnetic forces are opposite of one another, they attract each other. Which explains why the diagram of speakers vibrate! Also why we are able to hear sound from our headphones.
Step 3: Sanding Ends of Copper Wire
For this step you will need to use sandpaper to sand the ends of the copper wire. Make sure you don’t leave ANY red or whatever color your wire is, you want to sand off all of the paint on top of the wire itself.
Step 4: Inserting Magnets and Coil Into Cup
In this step you will need to place one magnet on top of the cup and the other magnet in the inside of the cup. After this, put the coils you wrapped and place it on top of the cup with the magnet. The coil should fit over the magnet because of the diameter of the glue stick is wide. Once you do this, place electrical tape over the magnet and coil to secure them in place. Leave the ends of the wire free of tape, because you will need to bend these to connect to the aux plug.
Step 5: Aux Cord
Take one end of the copper wire and place it in the hole of the aux plug. Once you do this, twist the wire to secure the wire in place. Make sure to wrap it tightly to have a better connection. Repeat this for the other side of the copper wire but this time place it in the other hole in the aux plug.
Step 6: Testing
Now to finally test! For this step you simply plug the aux plug into your phone/device and play music. It will work best if you have your device on full audio to make sure you can hear the music in your speakers/headphones you just made. Now listen carefully and enjoy the music!
Step 7: Extra Tips: If Your Headphones/speaker Does Not Work, Then Follow These Steps:
1.) Make sure the ends of the copper wire is sanded- no paint should be visible!
2.) Twist the ends of the wire tighter onto the aux cord
3.) Move wires and listen if there’s a change in sound/audio
4.) Tape coils tighter onto the cup and make sure it is touching the cup
Step 8: HOW Vibrations Turn Into What We Perceive As Sound
Speakers produce sound using vibration. The design allows the sound to be pushed out further than other objects such as a guitar, or other instruments. Speakers convert electrical energy to vibration, which turns into sound. Sound is a form of energy. Energy is the ability to move something over a distance against a force. Molecules are moving very quickly back and forth in sound energy. These molecules are moving at high rates of speed which creates waves. Sound energy moves by longitudinal waves (like a slinky) and these molecules crash and collide into each other thus creating vibrations. When we hear something vibrate, it causes energy to move by longitudinal waves. If the vibration is from about 60 Hz and 20,000 Hz it will cause your ear to vibrate which is sound.