never tested my car but im sure its pretty loud ive got:
alpine head unit 40x4
infinity 4x6 plates front
alpine 6.5s rear
boston acoustics tweeters rear
2 12" mtx blue thunder extreme
2 10" mtx blue thunder extreme
Crunch 1200x1 amp
mtx crossover
loud enough to set off car alarms at the mall and has made my rearview mirror and sun visors fall offnumerous times.