The Physics of Loudspeakers
The idea for the following video came from a collegue of mine who came up with the idea of creating a loudspeaker using a neodynium magnet and a bottle. I was very intrigued by the idea and played around with it, adding an iPod in order to play music.
Loudspeakers rarely get much attention in Physics lessons - they tend to be tagged on to the end of topics on electromagnetism and, following much more extensive work on motors, typically get forgotten about. Consequently I think this little demonstration, which can be performed as a class experiment, is a real gem! I often use it during Open Days, leave the music playing (I apologise for my corny choice of track!) and let people come and investigate.