[trishay79]

...do, what is it, what is it for?

[A G]

Extra Bass

[Rick N]

Makes bass for rap songs Coolio

[Jeremy S]

a subwoofer is a type of driver dedicated to the reproduction of bass frequencies, typically from about 20 Hz to perhaps 200 Hz in cone speakers, and in the case of a rotary woofer, all the way down to below 1 Hz. It is difficult for small loudspeakers in typical enclosures to reproduce frequencies below about 40-50 Hz, especially at high output levels (say, above 100 dB), as their cones must move farther than any practical driver construction can provide for, and so it is often advantageous to use a loudspeaker specifically designed for handling low frequencies at high power levels.