Great sound at high volume

Any suggestions in response to your post would have to be predicated on your budget. But, generally speaking, if very high volume is a major criteria, your best bet is to get horn speakers -- Klipsch K-horns would be an obvious choice, since they are very efficient and will play at ear-bleed levels.

Personally, I have yet to hear any horn speaker that delivers what I regard as "great sound". I concede I have not heard some of the latest horn models, so perhaps others can comment.

NHT 3.3's or 2.9's will play very loud.

all model ATC actives.

What are we talking about here? What's the budget? What do you consider very high volume? Very high volume only or does quality of sound have anything to do with things also? Seriously.

Not to mention what amp you would need. Some to many amplifiers will compress and/or constipate at higher volumes and/or when reproducing complex music.

The KAS (Kick Ass Speaker) from Montana Loudspeakers can deliver all the volume you will ever need with amazing clarity.

It can handle 900 watts continuous and 4000 watt peaks.

Known as the "Home Wrecker" The Montana KAS produces a three dimensional highly detailed sound-stage.