well, it all depends on your budget, the music type and the enclosure... DONT LET ANYONE TELL YOU WRONG, BUT THE RIGHT BOX IS THE DIFFERENCE!!! WEVE HAD THE CRAPIEST SUBS IN THE RIGHT BOX, and WOW!!!!

ive had the jl audio w7's for a while and they were LOOOUD.... 155 DB 2 10's..

i also have the thunder MTX 9500 .. its just as loud... but have a price range that is higher