Bowers & Wilkins ISW4 Passive in-wall or in-ceiling subwoofer (each)

High-performance hideaway bass from Bowers & Wilkins In my book, high-quality bass is an important component of any great-sounding stereo or home theater system. But not all rooms call for a big, boxy subwoofer taking up a large chunk of valuable floor space. Cue the Bowers & Wilkins ISW4 — a passive in-wall sub that delivers high-quality bass while hiding completely out of sight. The ISW4 lets you enjoy high-quality bass without sacrificing floor space (shown as part of a Bowers & Wilkins in-wall home theater system). Twin built-in woofers offer tight, responsive bass The old adage of "two is better than one" can be applied to subwoofers. I personally prefer the performance of two smaller drivers that combine to move more air than a single larger woofer on its own. The resulting bass is tight and responsive — terrific for music and movies alike. The ISW4 employs two 8" hybrid paper/aramid fiber cones to deliver deep, accurate bass all the way down to 21 Hz. It's