I did a search and found the world record

Team BS, a bunch of germans who competed in the US for the World Finals, hit 177.7 Decibels with 16 Treo CSX 12" subs and 64 DEI 1100D amps.

However, some guy named Nate Munson hit 170 with a single 9510, yeah a single 10 inch sub! and 2 Viper 2500's


Edit: Almost forgot to cite my sources.....

Team BS
http://www.termpro.com/asp/competito...26123&Season=0

Nathan Munson (look at the 2002 season)
http://www.termpro.com/asp/competito...13416&Season=0