Bi-amp, Bi Wire, Bridge???

Thanks for the link to McCormacks thread. It provided necessary reassurance to proceed with passive vertical bi-amp.

I read the Bryston manual and this is what lead me to proceed cautiously with bridging the amp. I knew that the KEF's run low impedance in most of the frequency range and hesitated (wisely it seems) to smoke them. Will proceed with passive vertical bi-amp using Kimber 8TC.

Running my speakers with biwire cable has always been the norm for me. But just a few weeks ago I tried vertical bi-amping two Linn AV5105 amps. The difference between the bi-amp configuration vs a single biwired 5105 is surprising. I did not expect such a noticeable improvement. The Linns are easy to bi-amp as they have the throughput.
My system has always been extremely minimalist with an integrated amp and a cdp. The additional wiring is a pain but the sound is worth it.

The KEF's get as low as 3.2 ohm and mostly around 6 ohm throughout the range. That's a no-no for bridging the Bryston according to:

http://bryston.com/BrystonSite05/pdfs/SSTAmplifiers/3B-4B-MANUAL-BRIDGED-MODE-INSERT.pdf

The 120Hz xover is suitable for passive biamping. The advantage of an active xover is removing the parasitic passive xover but, most often, that would require surgery on a PCB inside the speaker along with some deep knowledge of what you're replacing. Not recommended for a novice.

there is a recent thread here in which Steve McCormack provided detailed discussion of your.

Check it out.