A Powered subwoofers (or sub) is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies 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.