介紹些給你參考
效果很棒

The 272 PBM sealed enclosure subwoofer creates an impressively solid bass foundation for your music and movie special effects. It employs a massive 12" long throw driver with a full 2 inch, 4 layer voice coil and a 9.5 pound vented magnet structure. The built-in 225 watt amplifier is a fully discrete design, with a large torroidal transformer for efficient high current, high level drive. A precision 18dB per octave variable crossover with a bypass setting ensures smooth integration with the satellites and eliminates any possibility of audibly localizing the woofer. High and low level inputs with pass through connectors make it easy to connect the 272 PBM to virtually any home theater electronics.