[Cliff8928]

I'm sure if you setup the 8s correctly they should be loud enough, as long as they can produce the frequencies that you want. I have a set of since discontinued Kicker F69c4 (if i remember that right) 6x9s, which were their "freeair subwoofer" as they put it. They put out enough sound for the average person that would want to listen to their music loud, and manage to make things rattle on the car.