Sound at work

Here's an video from Lexus doing an acoustics demo. The last time I saw this done was when I was a college freshman and my Physics 3 teacher blew up a beaker. He used a frequency generator that some EE student had made from parts as a project and a speaker from the early 80s (which was also just lying around). The LF-A costs a quarter of a million dollars, but the end result is the same. Which is kind of fun.

The cool thing is the volume doesn't have to be loud if you can find and maintain the resonant frequency. Also cool: the amount of flex in the glass before it gives up.