I had 2 XXX 15's back during the summer of 04, when RE was a good company. I ran those subs in 10.5cu at 32hz with 150" of port off the US Amps De-3000 for part of the time and a MMats D3000.05 the rest of the time. They were far more crisp than any of the couple dozen W7 and Brahma builds I heard and only lagged slightly behind the IDMAX, although they got a lot louder. I did low 147's all day long at 38hz and the highest I hit was a 147.3. Were they in the same league as DD and Atomic in the SPL lanes? Not even close, but they were a VERY good street beater sub for someone that wanted to dominate the L7's that were so popular then.

My next build will be 2 DD 3510's or a single 9512. I have heard the DD sounds pretty good, and they do get loud as hell.