Speakers for a large vaulted room?

I have a listening room that is new to me. I have had trouble with my gear in this room and I want to see if anyone thinks the speakers will make a difference.

First, the room is rectangular with a brick fireplace flue that goes floor to ceiling pretty much dead center of the room. from front wall(speaker side) to back wall; a distance of 23'. I sit with my back to the 2 1/2' fireplace with all the empty space on either side of me. The walls on either side of me are 16' apart and only 4 1/2' tall then the ceiling take over and goes to a 12 or 13' peak.

Second, I am using an SP-6 preamp, V70 power amp from audio research and Magnapan IIIa's. I realize that the Magnepans need more power so I wanted to go with PSB Synchrony one's.
It will make them sound louder... not necessarily better.

Come to think of it, they may not even sound louder because volume level drops off quicker with increasing distance from the speaker when comparing a planar line source to a standard cone speaker system.
Volume is what I wanted to solve first, power is an issue for me I only get 70 watts a side, I don't listen loud, which is ideal, but some classical music or albums with a large dynamic range will clip. So the room size and the speakers I thought were my first concern. As I said, I'll change anything besides the amp and preamp.

So, even a more efficient speaker in terms of power needed wouldn't help me? What can I do?
The PSBs are going to be totally different than the Magnepans. I would say a bigger amp or bigger Maggies. Not sure if the bigger ones are more efficient. Other choices would be Soundlab Dynastat 88db or Emminent Technology LFT8 still 83db though. Should have more bottom end being a hybrid design. Very directional, so seating position small for the best sound. There are a number of choices from Martin Logan now too. Depends on budget.
"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.

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 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.
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.
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.
Especially since the ceiling limits so much I would continue to do the nearfield listening; it'll eliminate a lot of room issues.

You need to determine if you really want to trade away the panel sound. If you do not realize how vast the soundstage is, you may switch and lament it. I would suggest that if you have the space you might add another speaker to your stable rather than switch. If you still like the maggie, then keep it and swap them around occasionally. Check out my system here; you'll see I keep two speakers available to enjoy. This has brought tremendous pleasure, far more than owning one technology. I think you'd really enjoy having such variety.

I used the Tannoy Glenaire in review and it would make for a lovely nearfield speaker (see the review at Dagogo.com). It is a very easy speaker to drive, so it would be quite compatible with your current amp.

I would not preclude the exchange of amplification. If you like the pre, that's fine, but you've got a serious power problem with the clipping. Upping the power will do wonders not only for avoidance of clipping but in many other ways including extending the soundstage - a wonderful improvement and having more dynamic power to get better control of the speaker's drivers. The difference is quite dramatic. I would suggest no matter what speaker you secure that you eventually upgrade the power of your amplification. The nature of the speaker's sound will improve significantly when you do.

The only other solution to get more out of your amp performance is to move much farther toward a high efficiency speaker, something around the 92-95 dB or even higher range. That would be harder to find in a speaker with a smaller cabinet and will not solve the problem of your panel speakers clipping should you choose to keep them.

In relation to your room/logistics, perhaps you are thinking that you'll get far more placement options by shortening your speakers? Yes, you will. Lowering them will allow you to spread them out more, which will in a sense compensate slightly for the loss of taller soundstage; you can always tilt back the speakers to experiment with raising the soundstage of a shorter speaker. It may or may not be to your liking, but it's an option.

If you go with a shorter speaker and move them outward toward the walls, you will likely want to treat the walls with sound products, i.e. sound panels. In fact, even if you keep the Maggies I'd likely put sound panels on the head wall to diminish unwanted reflections. You might be surprised at the change in the sound of the room. :)
My room is not vaulted but it is 28 foot long and 20 foot wide plus it has a 9' ceiling with a 18" tray on top of that. Plus every corner opens up to a hallway, another room or a stairway upstairs (adding even more volume to fill.

I have had Genesis 501s with built in subs/amp and now I have Legacy Focus powered by a Legacy power amp for the stereo channels. I think it is 250 wpc into 4 ohms.

The legacy speakers are high efficiency and fill the room well. I have the speakers about 8 feet apart and my listning position is about 13' away from them. Sometimes when I am doing serious listning I pull the speakers from the wall which gets them about 11" from me.

I have not ever felt the need to add a sub or more power and the dynamics are great even with rock, classical or anything else I listen to.

Give the focus or whispers a try in the Legacy line up.
I have two listening rooms in upstairs rooms (in my home & cottage), but neither is as large as yours. Never the less, I've never had much luck using panels of any kind in those rooms. I just don't think dipoles lend themselves to angled side walls. I'd try shifting to a good dynamic speaker, not because of peak output, or sensitivity, but because I think you will have a much easier time getting integration with the room. Also, assuming it could be done, I'd consider setting up a near field listening set up turned sideways, with the speakers against one of the sloped walls, and you sitting against the other. This obviously wouldn't work with the tall Maggies, but a pair of short towers, or mini-monitors could be just the ticket set up that way! I wouldn't think in terms of "filling the space" so much as using the space to keep the room from getting in the way of the speaker/ear interface.
I'm at a loss as to how noone has pointed out the total disconnect of comparison between Magnepan and PSB.

The issue, primary issue for me, is the day and night difference in presentation between the two speakers. That's fundamental to this whole issue.

Good listening,
You want to keep your current amp,then the advice from johnk and duke is right. You need efficient and easy load/drive speakers(minimum92-93db and load of at 6-8 ohms, the higher the better). Your amp will sing and come alive with this type of speaker, and avoids the chase for ever more powerful amplifier syndrome. There are many good dynamic speakers to provide excellent soundstage(so you don`t have to rely on panel speakers exclusively).
Hi Sean,

I've been trying to get in touch with you on HTS. Can you get back with me?