The BC412 utilizes 4 long excursion 12inch drivers in Danleys' proprietary BC enclosure. The BC or Boundary Coupled subwoofer is a new class of subwoofer, delivering not only high efficiency and power handling but actual directivity. The BC family of subwoofers will stand up to the most demanding of applications. With lots of low end, a low box count and few amp channels, the Danley Sound Labs BC is the box of choice.