Bi-Amping Options B&W 801 Series 2

@lowrider57 Thanks for the compliment on my system, I’ve certainly been all-in since COVID struck which coincided with my retirement and my wife’s death May she rest in peace. 
Regarding the crossover, the speaker comes with two sets of speaker terminals, so that to drive them from a single amp, I would need strap the two positive terminals together and strap the two negative terminals together as well so that the power from the two wires could get to all four terminals and from there to all three drivers. 
It is my understanding that each original set of speaker terminals were connected to their own crossover network, and the drivers receive their signal from the crossover network internal to each speaker, but external to the amplifier. I include a picture of the crossover networks in my virtual system photos. Both crossovers inhabit the same circuit board, so it is difficult to distinguish them. 
I can definitely vouch for the fact that if I turn the one amp off driving the midrange and tweeter, all I hear is muffled bass notes, not at all distinct or loud; likewise, if I turn the amp feeding the bass drivers, all I hear is faint ‘tinny’ treble, again, not very distinct or loud. But when both amps are turned on I hear much more than the sun of the separate parts, the notes are clear, distinct, and loud, there is a sound stage (speakers disappear) instruments are well-placed within it, and there is plenty of ‘air’ around the instruments. As one listener noted, “I feel as if the musicians are in the room with me.” It is truly astonishing, and I didn’t have that kind of sound until I brought the B&W 801 speakers into the mix. They are truly a magnificent speaker: what you have (in the recording) is what you hear, no doubt. 

@xenolith Let me assure you, I am enjoying my new (to me) speakers. I bought the speakers used from a dealer in northern New Jersey. I won’t give their name because previous posts on this forum that referenced them were removed silently. Suffice to say that they would have been perfectly capable of replacing the original, if what I have is not original. I have seen some crossovers on eBay that are much heftier than mine, but I think I will hold what I’ve got for now.
I find your configuration interesting. I haven’t, as yet gone the mono-block route, I was already on the dual-mono path before I found out about it.
Your knowledge of this speaker ‘system’ (it’s really more than just a speaker, isn’t it?) far exceeds mine, but you seem to know what you’re talking about, and I like what I hear about it being easy to drive. The original designer, from accounts I’ve read was trying to correct the ‘muddy’ bass of the original series by going with a an intentionally stiffer material for the cone. The function of the optional bass alignment filter was to boost the signal to the bass and ‘wake it up’ as it were, as well as provide 6th order Butterworth filtering. Most people were happy with speaker as it was. B&W also offered 11” stands for them, but again the original designer said that was just to lift them up over furniture found in a typical recording studio, they weren’t necessary for use in the home.
Anyway, as I said, I’m enjoying them, and I’ll try driving them with the Rogue Stereo 100 and see what I think.

Thanks for the response, and that goes to everyone who has responded thus far. I really appreciate it.

@oldrooney  I'm so sorry for your loss.

I saw the pic of the crossover network, perhaps you can ask the dealer to explain the design. They are impressive speakers and it's great that they sound as good as they look.

My earlier comments were about adding the Rogue to drive the highs/mids where an external crossover or gain control is needed. You would need to verify that the internal crossovers are truly discreet; top and bottom drivers are separate.  

Yes, so sorry for your loss. May your memories of her remain vibrant and detailed for all of your days.

My best advice with these speakers is to give them tubes and the best of those that you can; yes, this means to disregard the advice to give them big solid state power; I’ve done both; with respect to sound quality, the former far exceeds the latter.

And most importantly, give them the cleanest path between them and their power...magic is then possible.

@xenolith Thank you. I just hooked up the Rogue Stereo 100 to the ‘High Frequency’ taps and the sound is so sweet. I prepared a long post to update everyone on this thread, but lost it all on an errant finger click trying to preview it. Oh well. The 2nd MC252 has Ben removed from the temporary system downstairs to drive the McIntosh XRT20s that are being installed on the ‘New System’ upstairs. If the XRT20’s need another MC252 to get off the ground they’ll get it. Testing the XRT20‘s revealed that they need a lot of juice to move the woofers; haven’t hooked up the tweeters yet: we’ll see. Again, thanks for the sympathy and advice.