high end" territory, but getting big bass out of ribbons is seriously challenging. The company has used conventional drivers in a THX Balanced Bass-line arrangement to solve this problem with its BGX-4850 in-wall subwoofer. The speaker uses balanced pairs of modules, each with 12 micro-woofers, to generate a thumping surface area equivalent to two 18-inch drivers. Add in a healthy 2,000-Watts of oomph, and you've got vibration-free bass coming out of your walls at "lifelike playback" levels, courtesy the first in-wall sub to earn THX Ultra2 certification. Everybody will know where that $7,000 went, so warn the neighbors.