I have been a biamping enthusiast since 1969. It is the single most efficient, and economical upgrade to the sound of a stereo system. I don't biamp I quad amp. Biamping is probably a better thing to do than bridging just to get more power.
Some of the reasons to bi amp have been lessened by the changing economics (ie amplifier power being "free" like computer memory and bandwidth) and high power being available.
But it is still and always will be very advantageous to eliminate the crossover network inside the speaker box. The crossover functions can be implemented much more accurately at line level. All the drivers get better damping. Each amplifier has reduced IM distortion because it is reproducing signals with narrower bandwidth. (in my case two to two and one half octaves versus ten full range)
Multiamping also makes it easier to tune your system to the room in the analog domain (Tweeter and Midrange "level controls" trash speaker damping) Hi level crossovers also eat a very large portion of your amplifier power. This is why you don't see very many four way systems without at least bi or tri amping.
Quote from a post at another forum Begin:
This is a nice dated piece from 1986 which I have been referring people to since I got onto the internet.
https://www.audiocontrol.com/downloads/tech-papers/tech-paper-102.pdf
https://www.audiocontrol.com/downloads/tech-papers/tech-paper-104.pdf
Also read the March 1969 issue of Radio Electronics which has an article by the Late Great Norman H Crowhurst and English audio engineer.
https://www.americanradiohistory.co...ronics/60s/1969/Radio-Electronics-1969-03.pdf
I feel that I became an audiophile exactly when I read the above mentioned article. It explains how active crossovers eliminate intermodulation.
starts on Page 32.
That was in March. In October he showed you how to build one:
https://www.americanradiohistory.co...ronics/60s/1969/Radio-Electronics-1969-10.pdf
Pages 42,43,44
Those two articles changed my life.
I was in the process of home building an electronic crossover using op amps based on info in Walt Jung and Don Lancaster books.
I had etched and was drilling a circuit board.
Then I ran into THIS:
https://pdfs.semanticscholar.org/f3...417.1160101081.1558408539-44099534.1558408539
The famous Linkwitz 1976 article on how to do it right.
https://www.xkitz.com/blogs/making-...g-the-case-for-active-crossovers-vs-passive-1
The Pioneer Series 20 (Pioneer Elite) D-23 was I believe the first commercial product to incorporate the Linkwitz criterion for preventing shift in the radiation pattern at the crossover. When the Pioneer came out I threw my project away.
I don't think the Pioneer engineers knew about Linkwitz. I think they figured it out independently.
https://www.hifiengine.com/manual_library/pioneer/d-23.shtml
I don't have a mini DSP yet. But it is likely just a matter of time. The more time has gone by since the above the more ways there are to skin the cat. You can buy kit or assembled circuit boards from all over. mini DSP. mini DSP even lower priced clones from Dayton audio and China
Lots of folks make crossovers now. The dbx drive rack and Behringer Ultras are great and reasonably priced and do LOTS of tricks.
In my opinion you should open the speaker box and wire straight to the drivers. You should include fuses and sometimes for tweeters series capacitors that don't affect the response in the drivers range. If you have more drivers than amplifiers (ie bi amping a three way) you need to leave part of the crossover in place. This may require careful examination of the speakers crossover network because engineers and manufacturers have gotten very sophisticated in that department. It really is better to remove the whole thing. In this day and age power amps and active crossovers are very inexpensive so if its a two way biamp it a three way tri amp and like I have done since 1977 quad amp a four way.
End Quote
Most of what I know about that is easy to access on the internet
BiAmping is technically more difficult and requires some reading and study so you don't blow up your speaker drivers. It is especially good if you are going to build DIY speakers. It is definitely not for everyone. But I believe strongly that all the best sounding systems incorporate it.