KEF Kube 12b Powered Subwoofer12 inch active subwoofer The Kube 12b is engineered to deliver the deepest bass for music and movies, if you want to feel the earth move look no further. Perfect for creating a deep and clean rumble in large rooms. The Kube 12b has a 300 Watts Class D amplifier and a large 12 inch driver as well as iBX technology to dynamically extend bass depth. Hear new dimensions in sound with Kube subwoofers The Kube 12b effortlessly unleashes explosive power. iBX