12-inch bass driver active subwoofer
 
Discover sound’s hidden depths with KEF Kube subwoofers. The Kube unleashes explosive power intelligently thanks to iBX technology that extends bass depth dynamically. Delivering immersive music and home theatre sounds that drive you deeper into the heart of the performance.

The Kube 12b features a 12" bass driver powered by a 300 watt RMS bespoke class D amplifier and 3 custom EQ settings for easy placement.
 
Full details here.