unexplained loss of spl

whats up everybody, i recently went through the line at a usaci sponsored competition for the first time in about 3 years. im running a RE SX18 in a 6ft^3 ported box tuned to about 36hz and all that is sitting in the extented cab of my ford ranger. but anyway, i used to hit right around 150db plus or minus a db, and this was about 3 years ago. i still have the same exact system, nothing changed except i had to install a new active crossover. 

this time around, i went through the line and actually turned up the boost on my crossover even more than i ever usually do even for a comp, and only hit a 142.4! a loss of about 8db. my question is, does anyone know if a well broken-in, 3 year old subwoofer, which still plays perfectly on any music i throw at it, can cause such a huge drop in decibels.  or can you think of anything else that could be the cause.

i know what you are saying but i really dont think that the crossover had anything to do with it and the reason is simple, its a better crossover with a higher voltage output than my old kicker crossover and at the time of the competition it was turned way up, probably way more than it should have been.  i did a little research on the difference between the crossovers and all i found out was that the new crossover outputs 7.5 volts and the old one only did 5 volts. and the other difference was that the crossover slope on the new one is 12db and the kicker had an 18db slope. so when you think about it it doesn't make any sense to blame the new crossover.

any other ideas?

the old crossover is shot, it self destructed at the competition in question, so i had to make a quick swap to the crossover thats in there now. which by the way is a Cache CEX 3-way crossover. 

DYohn, do you think its possible that there is some sort of output limiter/protection if you send it a clipped signal?  yeah, it sounds stupid but i figured i'd ask because it is supposed to be more of a sound quality device than a bass processor.