How to: Bi-Amping
Bi-amplification, or Bi-amping, is a technique which uses one amplifier for the low frequencies, and a second one for middle and high frequencies. This technique can allow users to take advantage of the strengths of each amplifier in its interaction with the speakers; i.e., use of a tube-type amp for the tweeters and a conventional one for the woofer. Through this technique, to properly do this, the amplifiers’ power must be balanced and the speakers must be well within their frequency and power limits. Tri-amping can be used on three-way speakers to power each driver individually.
This process should not be confused with bi-wiring, which uses a single amplification output source, but connects separately to the low frequency driver and to the midrange/tweeter.
True bi-amping involves hooking each amplifier to an electronic crossover that serves to supplant the passive crossover network built into the speaker (the passive crossover must be eliminated in order to achieve the advantages of bi-amping). This “active crossover” then connects to the appropriate speaker terminals; one for the woofer and another for the combined mid and high ranges.
Many of today’s 7.1 surround receivers give users the option , if they are only using two surround channels and therefore are in in a 5.1 speaker configuration, to assign the unused 6th and 7th channel amps to the front left and right channels to combine with those amps and have the ability to bi-wire the front left/right speakers with, now, two amps to use for each speaker (if those speakers have dual input terminals to bi-amp with).