Input on speaker sizing for a lively room.

Your Cantatas are already better than the vast majority of speakers. Match it up with one (maybe two) sealed quality subs and you might never need to look back. Of course, there are the Dunlavy Vs and VIs out there which are still competitive with the best speakers around. Also, I might mention that the Schumann Resonance tweaks from companies like Kemp and Acoustic Revive work beautifully with Dunlavy products and may get you where you want to be without having to shell out anything close to 15K.

If you can hear the Acoustic Zen Crescendo and Vienna Acoustics Liszt, those two would come to mind. I have Herron electronics and am now using the Liszt in my room. It's a wonderful speaker and does a lot of things right. It's a sleeper in their line. I haven't heard the Silverline or Verity. I have heard the Vandersteen Quatro and 5A carbons. A lot of folks love the sound of the Vandersteens but I don't. To me the midrange seems thick and congested and the bass isn't well balanced. Again that's just my opinion and your ears may tell a different story.

In a room that size, especially given that you have an open floorplan, imo looking through a somewhat unorthodox lens is called for.

Presumably most of your listening will be done fairly far from the speakers. As a result the ratio of direct to reverberant sound will be low, meaning that the reverberant sound will dominate your perceived tonal balance. So the relative importance of the off-axis energy will be much greater in your situation.

Also, it will not be easy to generate satisfying bass energy in a 34 x 22 foot room, especially when it's open into other rooms.

Most home audio speaker systems give much higher priority to the first-arrival sound than to the reverberant sound, and most of them are designed with the expectation of some reinforcement in the low end from the room.

Finally, the dynamic requirements to reach "realistic" sound pressure levels in such a room are greater than most home audio speaker systems are comfortable with.

Not long ago I assembled a system for a room four times the internal volume of yours, which was similarly open into other rooms. We paid a lot of attention to keeping the off-axis response smooth and well-controlled, in this case using a very gentle constant-directivity waveguide driven by a high quality compression driver, crossed over to two high quality 12" prosound midwoofers at the frequency where the woofers' radiation pattern matched that of the waveguide. Custom subwoofers delivered the bottom couple of octaves. If this sounds like a high-end PA or studio monitor type approach, it is; imo that's what it takes to really do the job well in such a large room.

I understand that you are looking for a smallish floorstander for the sake of WAF, so the specific approach I'm advocating may be impractical. So as you audition speakers, you might try this: Turn the volume level up a bit higher than normal and walk out of the room. Listen through the open doorway, but without a clear line-of-sight to the speakers. From out here, all you can hear is the reverberant field. Does it sound like there's live music happening back in the room? If so, put that speaker on your shortlist.

In my experience two welcome side-effects of getting the reverberant field right (assuming one gets other things right as well) are good tonal balance throughout the room (and even into adjacent rooms), and fatigue-free listening for hours on end. Note that supporting a natural-sounding reverberant field is what a good recital hall is all about. If a live piano sounds good in your room, a speaker that gets the reverberant field right will as well.

Imo, ime, ymmv, etc.

Duke
dealer/manufacturer

For low volume performance, you need a symmetrical room. No amount of money spent on speaker can fix the room.

Sounds like a job for the top Gallo Reference to me .