Top-tier performance from Paradigm The Defiance X15 subwoofer is one of Paradigm's biggest and loudest. It's a no-holds-barred heavyweight that was built to give your home system superior bass. This 92-pound sub features a 15-inch woofer powered by a built-in 900-watt amp to deliver room-shaking, perfectly balanced bass for just about any size of room. It's also app-controllable, letting you make adjustments on the fly with your phone or tablet. Better yet, it can also tune its sound to your room using the included calibrated mic, ensuring you're getting the best sound possible. What creates the thunder? Paradigm's pursuit of ultimate sound is deeply rooted in research. In studying how woofer cones and surrounds interact, they found that the spot where the two meet can cause some unwanted distortion, particularly at high excursion points. Paradigm found that by "overmolding" the woofer cone to the surround, they could drastically reduce distortion, while at the same time increasing the output of the subwoofer. Thus, their Active Ridge Technology (ART(tm)) surround was born. Close-up of the carbon-loaded polypropylene cone and ART surround. The Defiance X15 uses a lightweight, high-rigidity carbon-loaded polypropylene cone plus the ART surround. The bass remains tight and punctual, accentuating all the low-end nuances your music and movies might have with ease. It boasts solid low-frequency extension down to 18 Hz, so even if there's a deep, rumbling explosion or a room-shaking kick drum sample playing, the X15 can hit it deeply and with authority. Easy control and room correction Through the Paradigm Subwoofer Control App (free for iOS? and Android(tm)) you'll be able to adjust the sub's volume, low-pass filter, phase, more without having to mess with the controls on the back. The app includes three listening preset modes, Music, Movie, and Night, for dialing in the right bass for the occasion. It also has a nifty shortcut to the Anthem Room Correction (ARC(tm))