Beats by Addy and Alex, Period 1, 9th Grade Physics

Step 1: Materials

Materials

28 AWG wire (240 inches)

Neodymium magnet (x10)

Plastic cup (x2)

3.5 mm stereo jack

Wire cutters

Smart phone/computer/ipod

One square of sandpaper

Step 2: Procedure

Gather materials

Check local hardware stores or online for materials that you don’t already have Take the wire and tightly coil it around the magnets 74 times We experimented with multiple amounts of coils, and 74 worked the best out of the ones we tried. In addition to 74, we experimented with 14, 30, and 100 coils, and 74 worked better than all of them. We coil the wire because it makes it easier for the voice coil to attract and repel and helps the sound waves to pass through the coils After coiling, carefully remove the coil from the magnets while keeping the coils intact Place one magnet inside of the cup, centered The magnets in the center of the voice coil helps the the assembly vibrate and create better sound quality We chose our diaphragm material based on our observations. We observed that the plastic cup produced better sound quality than the foam cup Place three magnets in the center of the outside, circular surface Tape coiled wire around the outside magnets Sand the top half of the ends of the wire Look at the end of the wire and estimate how much half of the face of the wire is. It is fine if you don’t sand exactly half We sand the wire because the enamel of the wire acts as an insulator, stopping the current from passing through the wire. An insulator is any material that doesn’t act as a conductor, and doesn’t conduct electricity Wrap wire ends through the holes of the aux plug Any electronic device with 3.5 mm stereo jack compatibility

Step 3: 3 Main Components of a Speaker

Every basic speaker needs three main components; a permanent magnet, a voice coil and a diaphragm. The voice coil and the magnet vibrate. An alternating current switches the poles in the electromagnetic field, which causes the magnet to attract and repel with the voice coil, in turn causing the diaphragm to vibrate. Sound waves pass through the coils and the diaphragm, and we perceive the waves as audible sound.

Step 4: Sanding and Coiling

Coiling the wire strengthens the magnetic field around the wire, therefore strengthening the sound quality in the headphones. Sanding takes off the enamel coating, allowing the current to pass through and strengthen the magnetic field around the wire.

Step 5: Magnetizing

The permanent magnet provides a magnetic field which is strengthened by the voice coil. The magnetic field is made stronger with more permanent magnets. Alternating current constantly changes the magnetic field which causes the energy to decrease. The poles of the magnetic field switch when the current alternates, causing the magnet and voice coil to repel and attract, causing the diaphragm to vibrate.