Neodymium Magnet Loudspeaker

To get a good idea of the physics behind the functioning of a loudspeaker watch the video above.

youtube link here:

https://www.youtube.com/watch?v=B7p2FuJkzkc

In short, the loudspeaker uses the interaction between the temporary magnetism generated in a coil of current carrying wire and the permanent magnetism generated by a stationary neodymium magnet.

Components:
1 Large cilindrical neodymium magnet

2 meters 0.5mm copper wire

1 plastic plate

4 business cards / playing cards

2 Aligator cables

Tools:

Wire cutters

Hot glue gun

Stereo system OR phone + sound amplifier

Step 1: Create a 2cm High Paper Cylinder

Cut a 2 cm strip along the long side of an A4 page.

Paste some paper glue along this strip.

Wind the strip up to a width just wider than your magnet.

Secure the strip with some electrical tape.

Step 2: Connect the Cylinder and a Plastic Plate With Hot Glue

Wrap up the paper cylinder with 2m of 0.5mm copper wire.

Make sure the cylinder is centered

Allow 5 minutes or more for the hot glue to dry

Use a lighter or some sand paper to strip the ends of the copper wire

Step 3: Connect Speaker to Stereo Output and Test With Magnet

Speaker should work with both polarities, one of which may work better.

If the speaker works use some blue tac to secure the magnet to the table.

Step 4: Create Some Paper Springs With Business Cards

Adjust until the speaker works well.

See it in action in this video starting around the 9 minute mark: