ok so i replaced my rear deck speakers with some infinity reference ones. everything works all good but the bass from them makes the rear deck buzz. i am not sure but it might be the third brake light touching the rear window or it might be something completely different. has anyone had this problem before? i was thinking to get some foam and cover the underside of the deck with it, but not sure if that would stop my problem. give me some ideas of what i should do

 

Make sure the dust caps on the cones haven't come off. It's pretty common. If not, yeah, try damping the deck and see.

 

You can get one of those bass CDs and find what frequency is causing the vibration and it will give you time to see what is vibrating