what was your girlfriends car? The arrangement and volume of the space there could make a difference in output. are the subs facing in the same manner as they were in her car?

 

it could be the amp the rca cable shouldnt do i unless it has a split try using a friends amp and see what happens

 

yup it was the rca cables 1 was bad. now it BUMPS!!! still 1 question tho. when i turn songs at the very beg. the subs hit once. and also when i turn the volume past 0 it pounds once. any idea why?? DIrty Sound??