Ive got a nice empty cab built with MDF. Real solid. Id like to use it as a sub with my EBS 210 cab. The cab is 50 liters (or 1,75 feet^3 for you Americans refusin to use SI units ) The cab currently has a 12" hole in the baffle but a 15" can fit if I use my saw skills a bit. I wil tune in an SBB4 alignment for best transients. Which driver would you reckomend? I play only 4-string basses.