I have a friend that, after hearing about my atempt at DIY, wants to do something similar. He has 8 15" HX2 rockford fosgate 15's and wants to take 4 of them for a project. Problem is I don't have complete parameters for the woofer here is what I got: rockford HX2 15" fs 22hz vas 4.45cuft(126L) x-max 19mm Pe 1000watts voicecoil [email protected] This is all I have for this woofer. any help. I figured just looking at the parameters something in the niegbourhood of 4-5cuft ported tuned to 20hz or so. He already has these subs I told him to use 2 at the most and sell off the other two. I also can't see him needing more then 500watts as it has a similar x-max as a shiva or tempest, which would also best this $500 15" woofer. Kind of sad really these woofers weigh 40lbs and look pretty cool.