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

The Classic speakers don't have the resolution.

This is a load of bull. The Classic Audio keeps up with any of them. Its beryllium midrange field-coil driver is very fast, relaxed and revealing. The speaker uses Mundorf caps in the crossover with 6db slopes.

You need to do the math. You have a big room, and speakers with moderate efficiency (89-93 db) will not fit the bill with any integrated I know of, not if you want to fill the room with anything that sounds like real music. So if the speaker has less than 96 db I would strike it from the list, unless you feel like getting a 500 watt amplifier to drive them, because that is what you are going to need with speakers of lower efficiency.

For example, if you have a speaker of 91 db and a 500-watt amp, you will be able to play at exactly the same levels with a 125-watt amp if the speaker is 97 db. The reason is because our ears work on a logarithmic scale rather than a linear scale. So to get 3 db increase in volume requires double the amplifier power. 3 db is not a lot! 10 db sounds like it is twice as loud, but that takes 10X more power.

If you were using a smaller room this would be easy. But the advantage of a large room is that the virtual size of the musicians becomes life-like in the sound field- something you can't do in a small room. So you need a speaker with the bandwidth, resolution and efficiency. Most decent speakers have two of those three attributes. The reason I am an advocate of the Classic Audio Loudspeaker is that it has all three. So does the Audiokinesis Dreammaker, although it is slightly less efficient, it is still more efficient than most speakers mentioned so far.

The problem you are going to run into with speakers of lower efficiency is that by the time you get the life-like levels, you are going to be pushing the speaker pretty hard and its going to do some compression. Plus you can count the number of musical natural sounding amps that make 500 watts or more on one hand with fingers left over, price no object. That is why when you get into situations like this there is the expression 'gold-plated decibels'.

Go with a more efficient speaker and this will get a lot easier!

OHM F 5015's with 15" powered subs built in for ~$10,000 (if available currently) can fill that room as good as just about anything dsigned for home use, I would bet. The powered subs would take a lot of load off the main Luxman amp and could work very well I am thinking.

My OHM F5s which are similar but without powered subs running off my $3600 used BEl Canto ref1000m 500w/ch amps could even do a respectable job I bet. This combo has yet to show any signs of stress or breakup at any volume in my setup. The wide range OHM CLS Walsh driver that handles most music up to ~7Khz or so and minimizes demand on the tweeter is a big reason for that. Few other speaker designs can compare in terms of ability to go loud and clear, perhaps none at similar cost.

Older earlier generation OHM Walsh 4s or 5s might be had for less than $1000 used. I have used old OHM Walsh 2s outdoors even off an 80w/ch Tandberg receiver, and volume was never an issue. It sounded as much like live music as most anything I have ever heard, including many big buck reference systems. The sound of the older model OHM Walsh speakers are not as refined overall in most rooms as the latest and greatest, but might work very well for very little if room size and acoustics becomes the bottleneck towards achieving the kind of high end audiophile sound one might expect in most rooms.

Pro gear is more often applied in very large rooms/venues. Not as sexy, but perhaps the most bang per buck?

In addition to the other suggestions, if you can find them, Duntech Sovereigns or Dunlavy SC Vs or VIs could give you that big sound, but I doubt that the Luxman would be up to driving them to best effect in that big a room (especially the Sovereigns which, despite their relatively decent stated efficiency, really need an amp that can control their low frequency drivers).

If you really want to fill the room with your current equipment, I think Atmasphere's advice is the best; or else you can just use part of the room in a more nearfield setup as others have suggested, that would give you far more options. The glass walls will be an acoustic problem for you, I'm sure.

I'd say pick up a pair of old OHM Walsh 5s somewhere for <$1000 and give those a shot first before spending big bucks. You'd have little to loose and much to save/gain even if they do not cut it. They can be resold easily with little or no loss,or traded in to OHM for up to 40% discount on a newer pair if desired.

I would love to have a room that size for any OHMs and would never trade it if I did for anything in the smaller rooms most of us are limited to in our homes. I've found the OHm Walsh CLS speakers are NEVER the bottleneck. In your case, the amp would be, but it may still be good enough that it not matter. MAxing out the amp with the OHMs in a room that size should be an incredible experience that I would love to hear! That or the option of adding a good powered sub.

[url=http://www.stereophile.com/floorloudspeakers/687ohm/]1987 Stereophile Review of the OHM Walsh 5[/url]

Another good candidate to look at would be Tannoy larger Prestige line. Probably Westminster or better still the Westminster Royal SE. Had them for years in a room almost as large, driven by Cary 300SE (15w), then later Cary CAD805 (50w), filled the room sweetly without a sweat. Your Luxman will be more than up to task, I'm sure.

At one point, a friend looking to buy these speakers demoed them at my home and brought his Accuphase (less than) 100w integrated+Sony 555ES cdp if I recalled correctly, it sounded great too that he ended up with the Canterbury (one model down). Definitely worth to check out ie.if you don't mind/love their classic look.