I have just installed a pair of 6" x 8" German Maestro speakers into the front doors of my Bf (series 1) futura along with the same speakers in the back. At this stage all the speakers are running off the stock head unit.

Performance of these speakers is substantially better than the stock dual cones as it should be given the cost of the Maestros and the low quality of the standard speakers.

I have noticed that the front door trims now have vibrations at certain frequencies. It appears that it's actually the door trims and not the doors themselves and that it comes from the middle of the door rather than around the edges. I haven't taken the trims off again to have a look underneath but I reckon that there is some space between the door frame and the door trim and the sound pressure from the speakers is getting under the door trim and vibrating.

I'm looking at runnng a separate power amp and run the speakers full range at some stage so can only imagine that this vibration will only get worse with more power and oomph.

I was looking at Dynamat etc but reckon that it's more about containing the sound pressure to the front of the speaker and stopping it escaping under the door trims.

Has anyone tackled this problem and how did you go?