Screenshot from the YouTube channel Navin Khambhala # crazyNK
It's more of a cute creative project than an awesome innovative idea but I have to say I was impressed by the quality of the sound that got out of this homemade speaker.
The fact that the system using a CD isn't the main part of the build. It also uses Styrofoam as the base, wires, magnets and some aluminum glued on a piece of plastic for the membrane...