Hey Guys,
I found a Harman Kardon Sub Woofer on ebay which had been extracted from a Daimler. My alpine one sounds like a flapping wing beyond the + 3 setting on the head unit. I am reading some bits online that seem to suggest the Harman Kardon won't work in my alpinesystem.... Please offer some urgent pointers. Had wanted to ho through with the swap today!

 

The alpine is a dual-coil subwoofer, I don't know if the Harman Kardon is. You can repair your alpine unit for $20 with a new speaker surround - easy to do. Getting to the sub-woofer is more work than fixing the speaker

 

Did the fix RJ. The HK is a duo coil. Sounds fantastic but not as good. Will do the repair and put the Alpine back. You are way to accurate. Getting the speaker out is crazy pain!