Driver: Transforms an electrical signal into sound. Drivers come in many shapes and sizes, but all share the same function -- they make noise. Many speakers have multiple drivers to handle many frequencies. For example, "woofers" are large drivers that work well for low-frequency sounds like bass, while "tweeters" handle high frequencies.
Crossovers: These small relays take complex electrical signals and break them up into smaller parts to send to different drivers, isolating bass, treble, and mid-range frequencies.
Cabinet: This is the shell of a speaker where the electronics are housed. In order to eliminate noisy "resonance" or to get greater volume they are produced in a variety of shapes, sizes, and materials.[5]