My 2002 Tundra rear doors are creating a box-y resonance in the lower mids (JL 6.5 co-ax). I've used dynamat door kit and speaker mounting kit together, and will be adding an additional layer to try to kill the boomy coloration from the plastic door enclosure. Since these rear doors have no operating windows, would stuffing them with some sort of sound deadening material tighten things up?
Glasswolf suggested paint on dampener and EQ adjustment, but I wonder if I can build up enough mass to be effective.
My installer said to try more Dynamat on the entire door. What about putting some on the interior of the plastic door panel? Seems that's where the biggest problem is. Does anyone have experience with this situation? And what does happen with the speakers if I were to stuff the doors fiberglass in sulation?