I'm trying to get the most spl out of these subs and JL's recommendation of 1.75 seems too small? I've actually already tried the 1.75 ported box, but I think it will have more output in a bigger box. I called JL and they said 2.2 cu ft was the biggest I could go. Is this true because I was thinking about 5 cu ft for 2 12w7's? JL says that's too big and they won't perform properly. What is the biggest I can go without them sounding sloppy? Has anyone here tried them in bigger boxes?