i owned a couple of them back in the day. the smallest, weakest boxes i have ever owned. and that cheap grey plastic that they slapped on.. man. i hope they have gotten better as of late, though. this was back when crutchfield was my haven (great cust serv. rude tech support).
try explosiveaudiooutlet on ebay. That is where i got my 2 dual enclosures for my RE12's and they are built extremely well. I only paid 16 bucks apeice plus the shipping of course. I made sure that they were built the my subs specs, which they were. You would have to do the same if you want good results. Q-Logic boxes arent 3/4" mdf they are 3/8 i beleive and are very week.