Bi-amping Rules

When you bi-amp, you become a speaker designer, like it or not.  There was a time when it was a bit of a pig in a poke, but the possibilities were always there.  The miniDSP 2x4 active crossover only costs about $110 and it allows you to do DSP EQ on your system.  No matter the amps or the room you're using, you can measure what's coming out and create a correction filter to apply to the miniDSP.  

This means you can try whatever amps you like and just see how it goes.  When an amp only has a single driver as its load, it can do a whole lot better than you realize.  This also gives you the chance to mix tubes and solid state if you like.  Many have done that with great results.  Tweeters and mid-range drivers require little power.  Most of the power being used in the big systems is lost in the crossovers as well as being used to drive the low end.  And a solid state low end is just so much stronger than most tube amps as well.

Or you can be like most who just prefer to spend many, many thousands of dollars because someone told them they should trust the designers because they charge so much they must be good.  Why should you trust your own ears?

So given three way speakers, why stop at bi-amping when you can tri-amp? I am of course being facetious. Please let us know how this turns out.

For me..... low end must have high damping factor, tubes on highs SS on bottom and yes tramping is even beter. I've even heard quad and more amping. Basically I feel it about control.

Let's leave PA-systems out of the discussion. In them you want efficiency and the most bang for the buck at the least weight to haul around. You also have a brain behind the console to tweak the sound as he pleases and the music is produced rather than reproduced so there is no original to compare with. That is not to say that you don't need good sounding amps etc to get the venue rockin' and a satisfied audience that leaves saying that the sound system was the best they had ever heard...

Can you use different amps for hi/lo in a HiFi-system? Yes! But I recommend using similar amps. I used Nakamichi N620+N420+EC100 for many years and the sound was very balanced. Of course this configuration was intended by the manufacturer. My guess is that eg Linn LK140+LK85 would perform even better as they are also two versions of the same series of amps but with different power ratings.

If your speakers are simple 2-way with just a coil and a capacitor for filtering my recommendation is using two identical stereo-amps with one placed behind each speaker and low level passive x-overs that only employs 2 resistors and 2 capacitors for each channel. This is very simple, keeps the speaker cables short and leaves most of the PSU in the amps available for the woofers.

If the speakers have complex filters they usually not only divides the range and adjust levels but also includes phase correction components that may require some kind of delay line in the active x-over and you are in for a big challenge...