Tri-amping

Tri-amping is the practice of connecting three audio amplifiers to a loudspeaker unit: one to power the bass driver (woofer), one to power the mid-range and the third to power the treble driver (tweeter). A single amplifier can usually power a woofer, mid and tweeter only through a crossover filter, which protects each driver from signals outside its frequency range. However, the crossover itself wastes power, so tri-amping is a way to avoid this problem. The technique is primarily used in large-scale audio applications such as sound amplification for concerts, in portable powered speakers and by hi-fi enthusiasts.

The term derives from the prefix "tri-", meaning 'three', and "amp", a contraction of 'amplifier'.