Which speakers will fill 5,000 cubic ft coherently

One of the best rooms at RMAF to my ears was quite large and was filled effortlessly by the TAD/Pioneer speakers. They sounded superb and were one of the few rooms there that had me wanting to go back to listen to more. I believe they demand some current though and I didn't notice what amps you are using. If I had a $15k budget to pick speakers at RMAF I absolutely would not hesitate there: TAD. The S1-EX was astoundingly good at $9K, so you'll have change to buy different amps if you need'em. At the show they were driving them with BelCanto Ref1000's which sounded great with a wide range of source material. You could wait for the TAD Reference 1 to come to market but I think the price was going to be around $45k. If you check out the reviewers takes on RMAF and CES this year you'll notice them noted as favorite highlights by many a reviewer as well as folks in the forums here. I have no idea how your wife will feel about their looks, but I cannot imagine not liking the way they reproduce music.

FWIW, Classic Audio Reproductions loudspeakers utilize TAD/Pioneer drivers.

I didn't know that, but they sounded quite good with Ralph's amps at RMAF. I didn't go there because of Springbok10's comment about his wife's distaste for the appearance of horns. For me horns come in all shapes and sizes so I don't really get the blanket rejection. The CAR speakers were gorgeous to my eyes and did sound great, as I said. The TAD Pioneers would still get my vote and $ were I to choose. But, for a huge-room filling sound I do agree that horns are an excellent recommendation and the CAR speakers were outstanding and may indeed to better at filling a huge room. The CAR speakers were playing in one of the largest rooms at the show (greater in volume than Springbok10's) and had no problems filling that room with lifelike sound. The TAD Pioneers were in a large room as well, but the volume of that room was significantly smaller as the ceilings were lower. Still, it was probably equal to the volume of the room Springbok10 is trying to fill. Those speakers just seemed to do everything right.

sounds like time for Sunny brand speakers.
Larry