The car pulls up next to you at the stoplight, and you hear and feel the booming thumps of the speakers. Immediatly you can assume that this person knows how to rock, and probably has two gigantic subwoofers in his trunk. A subwoofer is the low-frequency speaker that makes the low thumping you hear, in fact a literal "boom box," or, as I call it, a thudbox. That's its purpose - play low beats well, let you feel it, and p**ses off the more conservative people around you.

There is already an entry about Home Cinema Sound Standards which includes speaker systems and subwoofers, but this entry will focus exclusively on those little bundles of joy and provide more information about them.

What are subwoofers?

For a basic definition, I cite Home Cinema Sound Standards:

The 'point one' in Dolby 5.1 [a surround sound system] refers to another separate channel specifically for low frequency sounds. A lot of the impact of cinema sound effects is felt in low frequency sounds - the crashing of the ocean waves, the 'thrup' of helicopter blades, the boom of the footstep of a Tyrannosaurus Rex. Humans cannot distinguish which direction low frequency sounds come from, so the speaker for these can go anywhere - for instance behind the sofa. It is usually big and box-shaped, and can make much lower frequency sounds than even the 'woofer' part of a normal speaker. It is therefore called a subwoofer.

More to follow, still researching...