Speakers typically use a ceramic (ferrite) magnet, or a Neodymium magnet mounted to the bottom of the speaker. Both magnet types work in the same way. However, a ceramic magnet is much larger than a Neodymium magnet and outputs less power despite its size. A Neodymium magnet is much smaller than a ceramic magnet and is more powerful. The main advantages of a speakers that use Neodymium magnet structures are their high-power output and the shallow mounting depth, two extremely important factors when installing speakers in a classic car or truck.