As a sidenote regarding the VMPS larger subs: NASA uses them. They bought them due to the fact at the time they were the most powerful subwoofer made. Very high SPL before distorting. You'd have to contact Brian Cheney, the owner, for more info. They also are very musical and articulate. They can be found used at nice discounts on Audiogon too. Ask over at audiocircle.com how four or six of them work!