Front Speaker Popping/Crackling

[golf4dj]

Looking for suggestions:

2008 X5 - Standard Sound System, 120K miles

Every time I open the passenger side door the speaker pops/crackles in that door only. When driving, the right passenger door speaker pops/crackles intermittently but at times does seem to coincide with vehicle movement such as stopping and accelerating. Also, there is no sound coming out of the passenger side speakers when the radio or any other input is selected as confirmed using the fade/balance adjustments.

At this point I have not popped the door panel off to see if something is not connected securely at the speakers.

I have searched the board and while many people have had issues with their audio systems I could not find any that seemed similar to mine.

Anyone have any suggestions on where to start?

Thanks,
DJ