Hey there Sam, sounds like you've been busy! I don't know anything about ohms, or the tech side of things, so I can't help ya with that.
My rear speakers have a bit lower volume than the fronts. If I had to put it in a %, I would say maybe 10-15%. Back in the day when I had the 'serious' systems in my cars (fonts, center channel, seperate tweeters for everything, mids, mid bass, subs, 4-7 amps, electronic x-overs, the works), we always went by 'Front main, rear fill'. We set them up so the majority of the sound was from the front speakers (dash and doors), and the rear door and rear deck would be fill in to balance everything out. Still plenty of volume and sound quality, but still a bit lower than the front. As far as I know, competition systems still do this, but I'm not sure as I've been out of that scene for quite a while.
I noticed this 'front main rear fill' balance on my Caddy's, Suburban, and also with the Vette. I take it as normal in comparison with my previous experience.
If your rear speakers are exceptionally lower in volume, maybe the rear channel on your head unit is exiting stage left (going bad), or the amps on those speakers are bad (I've heard that the speakers on a factory Bose system has their own individual amp).
Last but not least, maybe its working fine as it should, and you're just as disappointed with your factory system as I am with mine
Anyhoo, just another penny for my thoughts, keep the change. Cheers!
