My 91 300D has the typical door and parcel shelf speakers along with a set in the front doors all driven by the factory Becker unit. This thing has never sounded good (since I own it) but recently the door speakers sound like they are torn / cracked.

Looking to do an overhaul (of just the speakers) I popped open the covers (front & rear) to find out that an unemployed butcher had already replaced the rear speakers. Thankfully he hadn't touched the fronts and I haven't opened the doors just yet.

Question #1: When I disconnect the amp (?) in the trunk the door speakers go quiet and the other 4 keep working. Is this the way the system should work?

Question #2: What size are the speakers in the doors?

Question #3: The foam in the rear speaker grills is deteriorated and falling out. Any suggestions for replacing this?

Thanks in advance for any help.

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