I posted in the E60 discussion forum but I figure you guys here are a little more hands on and may be able to help me out.

During a drive the other day, the bass in my car just cut off entirely. I do have an aftermarket amp/sub hooked up, but they're working just fine. I even disconnected them entirely. It appears there's no low-end frequency being delivered to speakers under the seats. The other speakers all work fine. Has anyone had this issue or know what to look for in troubleshooting this? I'm not too knowledgeable with the car's wiring but I've already checked for loose connections to what I believe is the stock amp and a couple relevant fuses.

Any ideas? Much thanks as always.

 

Check the actual wiring on the mega connector to your MASK or CCC.