I think I decided on a driver a 12" Peerless XXSL driver. I plan on building a box with two passive radiators. I'm also researching a augmented PR design and may try that. The matching peerless pr is only $12 less then the active driver. Which seems quite expensive especially if I need two. I was thinking of using the PR from Dayton. What do you think? Do they have to be matching brand? Has anyone built a augmented PR design subwoofer? I plan on using an plat amp that maxes out at 450w 4ohm.