subwoofer

thumb|12-inch (30 cm) subwoofer Speaker driver|driver (loudspeaker). A driver is commonly installed in an enclosure (often a wooden cabinet) to prevent the sound waves coming off the back of the driver diaphragm from canceling out the sound waves being generated from the front of the subwoofer. thumb|A typical Hi-Fi subwoofer (r.), with the subwoofer loudspeaker built into a cabinet. On the left, a version with transparent cabinet is shown where the large magnet (grayish color) of the speaker driver can be seen in the middle, close to the brown Electrodynamic speaker driver#Components|damper.

A subwoofer (or sub) is a loudspeaker designed to reproduce low-pitched audio frequencies, known as bass and sub-bass, that are lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range that is covered by a subwoofer is about for consumer products, below for professional live sound, and below in THX-certified systems. Thus, one or more subwoofers are important for high-quality sound reproduction as they are responsible for the lowest two to three octaves of the ten octaves that are audible. This very low-frequency (VLF) range reproduces the natural fundamental tones of the bass drum, electric bass, double bass, grand piano, contrabassoon, tuba, in addition to thunder, gunshots, explosions, etc.