Speakers for a large vaulted room?

"So, even a more efficient speaker in terms of power needed wouldn't help me? What can I do?"

A more efficient speaker will indeed help you; the PSB Synchrony One is not a more efficienct speaker, or at least not significantly so. The Synchrony One is a 4 ohm speaker with a 2.83 volt sensitivity of 88 dB @ 1 meter. Converting to watts, that's an efficiency of 85 dB/1 watt/1 meter... certainly not "high efficiency".

Big room... unrestrained dynamics... 70 watts... 92 dB speakers will get you there... imo, ime, ymmv, etc.

Duke
dealer/manufacturer

Another room that screams for horns another owner who will just place another inefficient dynamic design and wonder why it does not sound so great.

Well I have had a similar problem in my new listening room. Much more space from side wall to listening position due to long wall placement, and a vaulted ceiling that peaks right down the middle of the room. I was having more sound issues than I ever hand to deal with before. Two posts on this thread are leading you in the right direction IMO. More efficient speakers and horns.

Let me further add this. In addition to higher efficiency and a horn/waveguide design, look for a speaker that is more flexible as to placement within the room and has the ability to allow for user tuning. My speakers are Audiokinesis Jazz Modules and I use them with amps ranging from 10 watts to 70 watts. They are 92 dB efficient, use a 90 degree waveguide, and allow for both bass (via adjustable port length) and high frequency (via external resistor swapping) tuning. In my room, the bass tuning capability solved my problem immediately. In your case you will find these speakers will load your room nicely with the amps you currently use. You will also be pleased with the dynamics and natural timbre of the sound, especially on classical music.

At 92+ dB efficiency you'll have many choices out there and I admit I'm a bit biased here, but Johnk's and Duke's advice shouldn't be ignored.

Well I would place the speakers no more then 8 feet apart and sit no more then 8 feet away from them. Remember this is not a PA System.... That should solve most all your problems unless you are married...

The best

PS. I am a dealer. Not for any of the gear that you have however.

My room is larger than yours, and I drive my Tannoy HPD 315's (12" Dual Concentric) mostly with 35Wpc, an old VAC PA 35.35. With these vintage speakers (though with custom cabinets, custom crossovers, and current-version "Hard Edge" surrounds from the Prestige line), the 35 year old drivers aren't quite the antiques they were, but anyway, they pressurize my large room very well, and the bass is outstanding. If you can, try to audition Tannoys, the 15" Glenaire should work nicely for your needs.