Hey Louis, I trust that you have a good driver on the Speed12 if it can blend with your speakers. Have you tried using these drivers in a dual-opposed sealed sub? Would obviously need to be twice as large, but the cabinet wouldn't have so stout due to natural vibration cancellation. It's been done before, but mostly in the SPL obsessed home theater crowd. With your drivers, I'm guessing you could have one tremendously potent & very musical sub.