Very BIG Room? Music and Home Theatre Challenge

I say look at some older klipsch Heritage speakers like the Lascalas or cornwalls, or Chorus. These are all around 100db efficient and work great in a big room. I have the Klipsch Epics Cf3's. They are 100 dB efficient and they can crank with uncompressed sound that can easily fill a large room. I can only imagine a room with those all around, it would be awesome. Their size and looks are perfect for a big space like that as well. Or look for some speakers that are used in a movie theater. I also vote for a front projection system of some kind. Mine is a 90" diagonal but will soon go up to a 106" when I get my new projector.
That room will be alot of fun to create. Best of Luck for your friend.

any comments on Wilsons for BIG rooms?

...thinking Watt Puppies, not Max, or WHAMM or Alexandria or whatever.....

and appreciate all the cautions about Maggies in a big room.

However, would those concerns be mitigated somewhat by sitting closer to the speakers? Or would the sound still be swallowed up?

Thanks for suggestions so far.

One option to consider is a line source speaker which has less db drop per distance than a point source speaker. I have seen and heard the Wisdom Audio million dollar home theater set up in a large venue with the sound radiating clearly throughout the exhibition hall of the Reno Home and Garden show. Very impressive! I ended up getting the Adrenaline Rush speaker system because of the impression it made on me. You might not want to spend a million dollars but I am sure that there is something about the line source phenomenon that will impress you.

Nope, can't do the Maggies for your room/application...pass.
It will be a dynamic downfall for you, and you'll be the only one excited about the prospect of good sound in the room.
I would recommend higher dynamic output systems,like Infinity Prelude MTS system for higher end, refined sound with dynamics and efficiency (multiple drivers/850w 12" woofers). Also, NHT's powered sub systems, like VT3's and such for the clear, detailed, uncolored, "Maggie sound" from piston speakers. These will give give you a solid blend of the clear refined sound you like,wiht the authority and projection of sound you need, with prescence/impact.
On the Mid-fi level, Klipsch Reference Horns will also be solid in the room, limit side and floor reflections greatly, for better sound in your difficult acoustic space for reflections..even a bit more than the other Dappolito designs. Still, all these Dappolito/horn/THX designs will help you here when you sit back further into the room, or are in the middle/back.
Again, otherwise, you need lots of acoustical pannels around the room, which you should do anyway, however.
Here's another "movie theater sound system" to look at and read about, to give you input. Check out www.professionalhomecinema.com, and consider.
Still, if I were putting together your system, and you said "Maggies" to me...I'd steer you toward the Infinities or NHT's likely. Otherwise, Wilson Cub's for more money, but tricker placment, high sensitivity and such. If you mentioned Wilson, I'd recommend these, they're Dappolito configured, as refined as you'll want, more placment options, and designed for movie playback, and high end sound.
good luck...lot's to consider.
Oh, I'd do big LCD or DLP for you in that room, yes.
Probably on at least a 140" screen or larger, and scaled to 720p or better

BTW, really in that large room, I'd be covering the concrete walls with 2x4" framing with drywall to help soften the sound. The hard walls will make your sound, well hard! Good for Viagra, not your sound system. You need balance here, not unyielding sound.
The blance of reverb should still be good, with the cement walls directly behind also. Then, just do some diffusion pannels around the room, on sides/front. This will be all you'll need trust me. You should be good to go acoustically...no large bare wall surfaces for you on front/sides!!!