Powering the low-frequency bass (woofers) separately from the high-frequency treble speakers (tweeters) in a sound system by using two audio amplifiers. The midrange speakers are tied to the tweeter section. However, the loudspeaker enclosure must accommodate this practive by having one set of terminals for the low end and another for the high end. Bi-amping is done to increase power for concert stage sound systems, and audiophiles may wire their systems this way because they believe separate circuits produce a cleaner sound.

Tri-Amping
Less common than bi-amping, tri-amping uses separate amplifiers for the bass, midrange and treble drivers in a speaker enclosure.