If your speakers sound a bit thin for your taste, then the new Magico Titan 15 will undoubtedly offer a rather potent solution.
The Titan 15 from Magico is an active subwoofer that features two Class D power amplifiers, each with 3200 watts of maximum output. They both drive a seperate 15-inch driver, placed opposite each other in the cabinet. According to the manufacturer, the total maximum amount of power delivered is a solid 6500 Watts. The cabinet is made of a solid block of aluminum, which is completely sealed. Magico says that the frequency range extends to below 20 Hz. For the human ear not perceptible anymore, but it may provide a gut feeling for special effects in movies and the like! An organ concert produced on a large church organ will undoubtedly shake the windows and neigbors too.
For anyone who needs to climb some stairs in an apartment building without an elevator: be warned. The Magico Titan 15 weighs a whopping 177 kilos, so some help with lifting is undoubtedly required. Once the sub is in place, you can adjust it to your liking. A DSP allows you to control it very precisely and adapt it to your speaker setup. If you are interested: the Titan 15 costs $32,000, available from sometime in the first quarter of next year.