Next up... new speakers...

For better or worse, my approach to building my system has been to progressively upgrade one component at a time as budget permits, working from the front end to the speakers and then looping back to the front end again.

When I last upgraded speakers some 9-10 years ago, the B&W N805s I chose were the strongest "link" in the chain... now, maybe not so much. :) The current system:

Cary 306 -> BAT VK-30 -> Ayre V5x -> B&W N805 + REL Stadium

Interconnects are Cardas Golden Cross XLR, speaker wires are Cardas Neutral Reference.

Now I have "the bug" again... the N805s have served me well, but its time to move on. Something more full range would be nice.

The room I'm working with is pretty large -- 20x27, a vaulted ceiling (14' at side walls, 17' at center), with one 20' end open to another 14x24 room.

I'm looking for suggestions for speakers to audition that would be synergistic with rest of the system, that can "energize" this large space.

Musical tastes run the gamut from rock to blues to jazz to classical, so one-trick ponies need not apply.

Budget... mid-to-hi 4 figures. What would *you* suggest?
Have you listened to Dynaudio C1's?
That's exactly what I was thinking; but I am biased being a Dynaudio dealer. Definitely worth a listen...
All you have given is a price range. And that you have a large room to fill.

This suggests you should look at larger three ways - however you will find it tough to find something as good as this monitor. It is one of the "gems" in B&W's line up - competing with speakers easily three times the cost. As you have had them for a long time then you must like the sound. You should look for larger powerful three ways with a response that competes with this Awesome on and off axis response (which has only a slight midrange "scoop") - not at all easy to achieve in the target price range you are aiming at - meaning I am sorry to say you may need to "up" the budget somewhat - your speakers, although bordering on small for such a large space, are no slouches!
I've heard the Coincident Super Eclipse III's with your Ayre amp (actually I think it was the VX5e) and they sounded superb together. They'd be worth an audition, though they've been replaced with a different model line which I cannot speak for in terms of matching with your amp.

Good luck!

With a room that size might the C2's or C4's be better if in the used market. I used to like B&w's - sonus faber but then I heard the C1's from Dynaudio. I do own the C1's now. The C1's with my Rel B3 really sound fantastic. The C4's with a REL B1 sound super fantastic but way out of my price range
AV123 LS9
Digital Phase AP-4s which were clearly superior to my Gallo Ref 3.1s, Martin Logans, Vandies, Maggies, Legacy's (all previously owned) and equal to or slightly better than my also current Dunlavy SC-IVs. A speaker you would have to hear to believe. New they start at about $2500, mine have a few factory tweaks which brought them up to about $3500. Highly recommended.
Ohm 200, 300 or Walsh 5 series 3 would do the trick. Nothing I know of near the price can "energize the room" better.
Post removed 
There's an Eggelston Rosa for sale on the gon right now that would be a good match. No affiliation with the seller what so ever. I used to own these speakers... they are fantastic and alot of speaker for the money at this price.
If I had a big room, and being willing to buy used, I would go for the Dyn C4's. When I had a 20x40 space that opened onto the rest of the house, that's exactly what I had. You would ultimately want to upgrade the amp, but they are really a great pair of speakers. Of course, even used, they'd be pushing your "upper 4 figures" budget.
Go for another Brit speaker.I sold B&W's for 6 years and think pair of 803S would really flip your switches.You could look for upscale monitor like ATC (used in many studios and Brit),Italian Sonus Fabers,JM Lab Utopia so you can use sub.But if you dug the 805 then a pair of 803S (or used $0K 803D which go as low as original 802N) would blow your mind.ATC is expensive but great (used i many studios and Brit).A great value brand is Usher.Used Revel Studios.Think also if you mght want to go 5.1.If so lower price and get high value return speaker like Usher,Totem,Gallo, .I like Silverline and Hyperion as they can be ru with low power and give good return.But would have helped if you mentioned some other brands you heard and folks could say "then try "X".But be careful as a speaker you might like may require a lot of power.I never recommended the big B&W's unless someone had 200 watts because though they were rated a high sensitivity 90db they had nasty impedance dip that required current.Re-post and tell what you liked.Red some online audio reviews.I like and their "Blue Moon" awards.Somes tuff might be worth hunting for.I hear intriguing things about Emerald CS-2 with built in DSP.For imaging monitors are usually best bet( and you have great sub) so what about JM Lab Mini Utopias?New kid on block Mark & Daniel get big buzz.Get out to shops make your own critques and then get back and say "what else is in this clas or has "X" typer of sound".
Todster, I too had a pair of N805 with a Velodyne HGS-12 with a room dimensions just a bit smaller than you. I have always liked the B&W sound. I have recently rebuilt the entire system around a pair of Coincident Elcipse lll with upgraded wiring and spikes. They are driven by a BAT VK 31SE pre and a pair of NuForce 9SE V2 Amps. Front end is a Esoteric SZ-1 feeding a MSB Power DAC. All JPS Superconductor cables. The speakers could use a subwoofer to fill the room but everything about the system is more real and dimensional than the B&W setup. I guess the biggest difference is that the present setup makes me want to listen more often and for longer periods of time. Another speaker not mentioned are the Audio Physics. This was the other brand I was considering (Scorpios).
If you are thinking of a bigger B&W - just a reminder about my warning about on axis and off axis dispersion (which is unsurpassed in your N805 compared to all B&W's apart from the top of the line 4 way Nautilus and the old silver signature, if I recall but don't hold me to that one).

Generally the bigger B&W models simply achieve more SPL output by raising the tweeter crossover point and adding woofers to assist the famous B&W kevlar mid. (Tweeters have a tough job when driven low and without any baffle support - as in a B&W design - so raising the crossover eases their task - same idea for the midrange when you add a woofer)

Consider that what you have is an extremely good speaker - just it can't play loud before compression will affect it and it is limited on bass extension....but very very hard to beat in all other aspects.
You should look into horns I have a 30ft-20ft -13ft h sloped room designed for audio, no extra room to pressurize as you do and the only designs in loudspeakers that do pressurize this space are horn loudspeakers with bass horns.
Vandersteen Quatros would be an excellent choice.