I've heard a pair of those subs as well. They were standing right next to each other in the corner of the room, powered by external amps. Their ability to truly pressurize the room was astounding. You know when you're on the freeway (Not a freeway in LA, as you need to be moving...) and you roll down only one window, how the air rushes in and causes fluctuating pressure? Well, on one particular 17Hz organ note, that's what the room felt like. It's like the air turned to liquid and was pushing against all my internal organs. WOW.
I would highly recommend purchasing dedicated amps for those baddies. I don't think any receiver's amp could really do them justice.
