If you are into high end audio this project is probably not for you. If you are into tinkering with electronics then dig in. RimstarOrg shows us how to build a Piezoelectric Crystal Speaker. He took a Rochelle Salt Crystal that he made and electrically connected to it using some tinfoil, once rubber banded to a tin can for amplification the speaker was complete. When an alternating voltage is applied to the crystal it will resonate, only problem is that the standard output from his clock radio was not enough to make it loud enough. A transformer wired to amplify the input voltage was used to increase the volume. He then shows some experiments that demonstrate various methods of amplifying the sound using things such as cones.