It's also really great to show younger children and students to explain how speakers work. It would be ideal for a science class as there are very few components and all that can be found around the home. To assist in the learning side of it, I'll be sharing how I understand it works in the last step.
Step 1: What you'll need:
- A Styrofoam/paper cup (don't try a plastic one, it won't vibrate well enough)
- A small magnet. Doesn't really matter as long as it's small, and a magnet.
- A 3.5mm headphone jack. This can be salvaged by cutting it off a broken pair of headphones or similar item.
- Some copper wire (can be attained by taking apart old TVs, stereos, but you'll probably have some lying around). It must be copper, as it is the most magnetic and conductive material that's readily available to be scrounged from around the house.
- A C or D battery/Any smallish cylinder that has a radius a cm or two smaller than the girth of your cup
- Sticky Tape and popsicle sticks (it turns out you don't really need these, so don't bother if you don't have any lying around)
- Some alligator clips. If you have some wire and a soldering iron, they'll work too for a more permanent solution, but that makes much more work.
- Something that you can plug the speaker into. I used an iPod touch just to test it, but you'll find an older stand alone radio works better as the iPod had only enough power to make the speakers whisper quiet.