Big, big room -- which 10-20k speakers?

While I in no way consider myself in the same class of expertise as some of the respondents, I would suggest a look at Legacy Audio. Legacy is not as exotic as most of the suggestions here; But I heard the newest version of the Whispers at CES 2 years ago. The only speaker I liked better was the Anat Studio II, which is exponentially more expensive. I have a similar size room. I use two Legacy Focus and the sound really is unbelievable. I have a bit more power available in my amp which may help; But the New Whispers come with built in dual 500 watt Amps powering four 15 inch drivers each side. The extra power and piston area will surely go along way toward filling a large room. They are also very efficient. Have fun designing!
http://www.legacyaudio.com/products/view/whisper-xd/

There are so many choices to make, but only you know the kind of sound you are looking for. My room is essentially 20 X 30 X 25 high. My main speakers Coincident Pure Reference I bought used, two years old. My mono amps are PassLabs XA100.5's. They each drive 100 watts in pure class 'A' sound. Coincident speakers can be driven by as little as 25 watts or 500 watts, your choice. Right now I can drive well over 106 SPL at 10 feet. In my own humble opinion it is more about the sound you want and enjoy than an absolute number of power watts. All speakers are different at different levels of sound. Take time! By the way I also have two SVS Ultra13 subs that are blended in and helps create my own masterpiece. I had a friend down from Michigan to spend a few hours listening. He was astounded! And I had sold him previously, my Legacy Focus, which he loves.
Coincident speakers are built to hold an average 6 to 8 ohms across the frequency band to make selecting a power amp easier. These large speakers, weigh over 200 pounds and are reasonably priced used at around 10K versus 22K new.
The other choice to consider would be the BE-20 at roughly the same price. The sound is a little fuller. Usher BE-20 is their top of the line.
Either way you can't go wrong.
Choices choices nothing but choices.
Good luck and happy hunting!
Rich

I am envious of your room dimensions, especially the ceilings. Way to go!
A sub/sat system might surprise you...utilizing two identical subs of good quality.
But for stereo, I recommend Legacy Signature II's or better. I have the Sig IIs and they are indeed full range speakers in my room. Although, being so large, I would consider a speaker more suited for my smallish, cube-like listening room. With treated walls, my Sig II's are almost too much. Sub-wise: in black, I would consider selling my pair of Sunfire Professionals. They were the largest of that line of Sunfire sub-woofers, driver-wise as well as "Carver watts" power output. tmon41@hotmail.com for any continued communication.
Whatever you do, take advantage of your wonderful listening area by purchasing speakers that are large enough to take FULL advantage of such a "space filled" area for acoustic reproduction. If you use subs, get them in exact matching pairs, and take home two. Do not let that glorious listening space be ignored.
Good luck and enjoy the search.

Truthfully Envious, tonehead

Rr999,

We have an essentially open first floor in our home. The kitchen, entry, dining room and back area are all open. Some walls are as far apart as over 50 feet and some of the ceiling space is over 15 feet high.

Having said that, we've owned Wilson speakers, including the Alexandria X-2's mated with a pair of Watchdog subwoofers.

But nothing filled our space with as much quality sound as our Anat III Signature Professionals. The powered sub could pressurize our very large space without any additional subs and the quality of the bass was more satisfying than the X-2's as well.

If you haven't heard a pair of Anats, please do. You won't be disappointed . . . either with the audition (assuming the setup has been done properly, of course) or with hearing them in your large room.

Those speakers are nothing short of my remarkable, and I've heard (and owned) my fair share of competitors.

Joel

Well, I'm a bit late responding, but, since no one has mentioned them yet, here goes.

With your stated tastes, you actually won't need super-efficient horns, etc., to listen to lifelike levels of music, IMHO. My only caveat is that I have been to some rock concerts where the sound was so loud I had ringing in my ears after the concert...I'm presuming you aren't seeking that level of sound pressure!

First, as noted above by Bvdiman, your Luxman is 'only' rated at 120 WPC for 8 ohms. However, the 509u's 240 WPC rating for 4 ohms is normally a good indicator of an amplifier design that does have the ability to deliver enough current to properly drive most speakers.

I believe you really owe yourself a trip to audition the Magnepan 20.7 speakers. Magnepans (when properly placed) will fill a large room with the most lifelike music I've ever encountered. Dating back to their beginnings, when the Magnepan Tympani was declared their new reference speaker when reviewed in The Absolute Sound, Magnepan has repeatedly raised the bar vis-a-vis lifelike musical reproduction.

When paired with a superior subwoofer that can accurately produce the bottom half of the bottom octave of music (I presently use an M&K, and would suggest you consider the M&K MX5000 with the upper filter set to coincide with the 3db rolloff point of your main speakers) I've found that friends who have invested a LOT more than I have marvel at the natural musicality of my Magnepans.

Yes, I know they aren't the most efficient speaker ever manufactured. Yes, they do require placement away from a back wall to produce the best sound (one reason they sound so good in a larger room?). No, they don't have some magical unicorn horn dust sprinkled on the unobtanium drivers or the snob appeal of some unique designs. What they do so well is allow you to close your eyes and 'be there' with a recreation of the recorded performance that can be stunning.

I wish you good fortune with your quest!