Powered Box Subwoofer -12" 325 watt - Satin Black. Clean, powerful deep bass is what separates a great sound system from a merely good one. The 444SB subwoofer includes powerful low-distortion amplifiers and low-resonance, long-throw drivers, housed in a heavily braced, non-resonant sealed box enclosure. We have chosen this "acoustic suspension" approach because it ensures smooth, uniform bass all the way down to the lowest audible frequencies with no unwanted peaks or dips. It does not hype any frequency and it never falls into the trap of substituting loud, muddy "one note" bass in place of accurate, extended, natural response. But Atlantic doesn?t stop there. We have developed an exclusive design feature called Clear Filter Technology that assures clean, articulate, musical bass reproduction at all times, regardless of how loud you play an Atlantic Technology 444SB subwoofer.