non-edeaded door shakes? good/bad?

[lotas]

Hey im looking for someone to help me understand this on more of a mechanical/audio level (not sure what you would call it). My right door is edeading in strips and then big layers around the speaker. When my midbass hits or the sub hits, the left door (my driver side) mirror shakes and vibrates pretty bad, i mean you can see everything shake, but the left does not. What exactly is causing this? The waves are going straight to the metal causing the door to shake and on the other side are bouncing off the edead back into the car or what?

thanks :)