Each drive unit of a speaker is driven by a separate amp channel, so a pair of two-way speakers needs two stereo amps, and two runs of cable to each speaker. See biwiring.

The utilization of two amplifiers in a given sound system in order to separately amplify different frequency ranges and thereby reduces distortion. Usually, a full-range audio signal is divided by means of an electric crossover; one amp is designated for low frequencies, while the other is designated for highs.

Using separate amplifiers to power the crossover-separated drivers in a speaker system. When a powered subwoofer is added to a system, the latter automatically becomes biamped, with the satellites separately amplified from the subwoofer. With the right speakers, biamping can boost the output capabilities of a sound system considerably.