The Atlantic Technology AT-2
Atlantic Technology's AT-1, which uses their patented H-PAS venting technology, was one of the hits of last year's CES, and the positive impression was confirmed in Erick Lichte's review (September 2011). The H-PAS approach has now been applied to the new AT-2 ($1800/pair). The 3dB point is specified as 41Hz, which I'm told is an anechoic figure. This normally translates to in-room response to the low 30s, and the sound of the AT-2 in the Venetian's less-than-ideal space seemed to confirm this.