Hi Mike,
Does your NC already have rear speakers? ISTR that some models don’t.
I did mine as part of a larger project to install sound deadening a while back, so unfortunately I don’t have the ‘right’ photos, but I have an NC2 with factory rears. Order of operations:-
- Strip the rear plastic trims
- Demount the speaker bracket + existing speakers
- Remove existing speakers; they are glued on to the bracket - and I am 99% sure that they were screwed as well with short flange head screws. Removed screws, fixed bracket in vice, worked a Stanley blade/chisel around the perimeter to break the glue and pry off the old speaker
- Open up the hole in the bracket to accept the new speakers - may be optional depending on the size and how you mount your new speakers. The bracket has a lip around the hole to add strength - I ended up marking and cutting the wider hole - it’s only a few mm bigger - with a death wheel in a dremel that removed this lip.
- Mount new speakers. Again, I am 99% sure I just re-used the existing screws.
- Add foam around perimeter of speakers (if you are v careful, you can cut away the foam off the old speakers and re-use, but I just used leftover sound insulation foam
- I cut the connectors off the old speakers and soldered to the new ones so I could re-use factory connectors & wiring.
- Test & Reassemble
Speakers: Alpine SXE0825S
The bit that took the longest was working out how to open up the holes in the bracket to make everything fit. After some trial & error, the dremel ended up being the best solution for me.
As to the end result, I have mine faded a long way forward so that they don’t overpower the door speakers, being so close to your head.
Hope this helps - good luck!