Thanks, read your info...now I know it's a mach 1000 system. Should rattle windows, it does not. Something is missing (boom)You don't have subwoofers stock with the Mach 460 system. You have low-range speakers that deliver the bass and low ranges. You could have a blow amp or two. In the convertible they are located behind the rear seats and mounted on top of the wheel well hump. Dig around and you will find them. I would first just check all the connections and if you have a multimeter check to see if they are getting power. If they are hooked up and getting power they might be blown. Are you getting any sound out of the speakers at all? You could check the connections to the speakers as well.
There's a whole ton of info on this site for the mach systems: Mach 460 Information