Fill me in on bi-amping speakers.

wild-bill

Can someone explain in detail what's going on when you bi amp your speakers? Is one amp for the woofers and the other for the tweeters? Do you need active crossovers on the amps or will the speaker's crossover network take care of everything? And can you use 2 different brands and models amps as long as the levels can be adjusted seperately to match them up?

[Deleted User]

Hello,
Here is a copy of the information Polk gives as part of their FAQ:
"Bi-amping:
True bi-amplifying involves using an outboard electronic crossover, multiple amplifiers and removal of the internal passive crossover of the speaker. We're not going to tell you how to do all that because it is expensive, entails a lot of work and unless you REALLY know what you're doing, you may get worse sound than you started with. Most folks drop the idea right about now in the explanation process. But a few brave souls try half-baked bi-amping where two stereo amplifiers are used to drive one pair of speakers: one amp drives the low frequency section of the speaker and another drives the high frequency section and the passive crossover remains intact as illustrated. The benefits of bi-amping compared to bi-wiring are subtle, but like choosing wires you can try different combinations of amplifiers to tailor the sound. For example, many audiophiles prefer the smoothness and silkiness of tube amplifiers for high frequencies but feel that solid-state amps do a better job on delivering high current punch for woofers. By bi-amping you can get the best of both worlds. But if the gains of the two amplifiers are very different from one another, the tweeter will play at a level very different from that of the woofer and you will wind up with sound that is obviously inferior to single amplification. If you're going to try bi-amplifying, use power amplifiers with identical gain settings or variable gain controls. Bi-amplifying is not for the faint of heart or the casual audio enthusiast. Most important of all REMOVE THE FLAT METAL JUMPERS BETWEEN THE TWO SETS OF SPEAKER TERMINALS OR YOU WILL DAMAGE YOUR AMPLIFIERS! "
Regards, Ken

John K.

Bill, welcome to Club Polk. Probably the two most significant terms in that Polk FAQ are " True" and "half-baked". Almost no one does true bi-amping for a home setup because its complication and expense overwhelm the modest benefits available in home use. The "half-baked" procedure has very little benefit and the so-called bi-amping feature advertised by some one amplifier receivers has none.

In short, the answers to your three latter sentences are: yes; yes/no; yes.

wild-bill

Thanks Ken and John. So there's not much benefit in true bi amping-interesting. I thought there would be. I guess it could come in handy if you just happen to have 2 small amps instead of 1 large one. That way you could get all of your available power to 1 set of speakers.

mdaudioguy

It's a bit silly, IMHO, that speaker manufacturers seem to feel compelled to make almost their entire line "bi-ampable/bi-wirable".