A subwoofer (or sub) is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audiofrequencies known    as bass.The typical frequency  range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound,    and below 80 Hz in THX-approved systems. Subwoofers are intended to augment the low frequency range of loudspeakers covering higher    frequency bands.While the term "subwoofer" technically only refers to the speaker driver, in common  parlance, the term often refers to a    subwoofer driver mounted in a speaker enclosure (cabinet).
Subwoofer