Boston Acoustics enclosures or sub boxes don't mess around.  Every enclosure is designed around it's close kin, the subwoofer.  It's not only the small things like mounting depth, and the subwoofer's mounting circumference that come into play with these boxes.  Boston Acoustics' subwoofer boxes go to the next level, everything from the MDF, cubic ft per sub, terminals, and dadoed edges for a perfect seal make  Boston Acoustic sub boxes something to behold.  You can't go wrong by adding a factory tuned subwoofer enclosure from Boston Acoustics to your car stereo system.