i've had this consistent rattle from the left front for over year now and it only happens when i play bass heavy music. i've never been one to have bass level maxed, in fact i'm always at 0 and treble at +1. i took the car in about 10k ago and the dealership did nothing to stop the rattle, they said the speaker was fine. what else could the problem be?

 

Seriously doubt it but you might want to take off the door panel and check the clips which hold the door in. Also, check the bracket holding in the tweeter. Lastly, I'd check the screws on the driver to see if they backed out. I seriously doubt it but these few things would be a start.