Anyone had issues with the inner door panel rattling when playing music at louder levels. I have my Utopia's crossover set at 63 hz, and at certain notes I can hear a very noticeable vibration/rattling coming from the passenger side door, seems to be in the middle of the door or towards the front. Anyone have any good suggestions on eliminating the unwanted noise. A friend of mine mentioned putting balled up socks between the plastic panel and the metal door panel. Any other suggestions or fixes? I have a ton of dynamat left over, and I read online its recommended to dynamat the inner plastic door panels too, but dynamat does not get rid of rattles, only reduces unwanted outside noise.

 

what about that special sound proofing material used in recording studios ?