Very nice. I'm looking forward to seeing how your enclosure mod turns out. I am planning the same mod when it warms up.

IMO all the speakers in the e53 need to be replaced. Mine is an '05 with premium and dsp, I recently faded the audio to each corner of the vehicle with bass turned up, treble down, and found that 3 of 4 6-1/2"s are blown. So I just purchased 2 6-1/2" MB Quart component sets (MB Quart Premium PVI216, $119 each set on Amazon).

I took apart my right rear door panel (followed BSW online video instructions which were very helpful), removed both the 2-1/2" and 6-1/2" mid to take measurements...getting the new speakers in the stock locations will certainly not be easy; will require modifying the speaker mounting assy's. The 6-1/2"s especially will be difficult to work with, the factory cowling is basically part of the speaker, notice the speaker leads are built into the outer plastic tube. Looks like I will have to destroy the factory speakers just to get them out of the plastic cowling. The 2-1/2"s are going to be replaced with tweeters in the rear doors. I will have to look more closely when the new speakers arrive, but I suspect this install won't be too bad.

I included a pic of the two rear door speakers. They appear to be good quality drivers, but I imagine the upgrades will be night and day. Also included a pic of my Nakamichi amp standing by ready to install if the factory amp can't power the new speakers.

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