[so-cali]

that doesnt sound like blown speakers to me. i dont think that blown speakers just decide to turn off and on from time to time and whenever you hit a bump.

When i put my aftermarket eclipse's in i had sorta the same problem with the sound turning on and off. I the speakers out and found that i had done a poor soldering job and bits of the wire would touch other parts of metal on the door and each other. everytime the wires would shift around in the speker housing the sound would stop and then come back on a few minutes later.

My advice would be to take all the connections off and check the wires and harnesses and everything. Look for breaks in the insulation of the wires and then make sure the harnesses all have a good solid connection with the wire and connector when you put everything back together. My guess is that it turns on when you hit a bumb because some connection is made that wasnt there before when the wire shifts position.

If you still have problems, test a different pair of speakers from a buddies ride that you know work and see if the same problem arises. If its solved with the new speakers then your factory ones dont work. If its the same then you've got a problem with something in the car (probably the cd player, head unit, wiring, fuses, etc.)