pipes

Have a set of SWR-1042's from Alpine sitting here collecting dust. Are you able to recone these with FI soft parts?

From what your stated goals have been - getting louder and sounding better than a 15" Type R plus utilizing your amps power range - I would personally go with two 12" RL-p's. It would match your power better than any of the 18s your looking at. And you'd only sacrifice a very small amount of cone area to double your power handling capabilities.

Thanks, I've got pictures of the woofer already but I don't have time to build the box for a couple weeks. I'll post build pics and whatnot when I get to it! I can't wait to hear it.

Is 81 square inches of port area enough for an RL-p 18? The box I'm thinking of building is sub up ports back(2, with bent-mdf-flares) in the trunk of a 94 cadillac deville. Net volume is about 6.4ft^3 tuned to just under 27hz. The two ports are 3x13.5 and then flared exit. It will only be seeing about 600-700 watts (Crossfire 1502 bridged)