Jscottm, you hit on some good points, exactly as I remember them. First and foremost, the 80's was a fantastic time to get into music! But I'll digress here and leave that at that ☺... On the bose system, the center speaker did kill the left - right balance; the dash speakers were not true tweeters at all, I measured their outputs well into mid range, also, they were of course made of paper. However, for the average Joe, the sound was decent, better off the line than non-bose. Your comment on "rear fill", what I tend to call surround sound, hits the nail on the head. I think the non-bose system, overall, was made to be overhauled by people who care, or serve the general population of people who don't. The bose, in my opinion, was meant to serve as an "upgrade" for nearly the same general population of people--not targeted to the audiophile whatsoever. I suppose if I had to recommend a system configuration for those with non-bose, it would be similar to yours; tweeters in the pillars are a very good idea, use the dash L/R to cover mid-high range, then front doors for woofers for low range (with optional sub box under the back seat). I'd use 3-ways in the back doors. Top it all off with a decent amp w/crossover and add an equalizer, then tweak as necessary. Btw, it's impressive that you do your own caps on tweeters (no tweeter should be without a capacitor)--it's been my experience that folks who take that leap into soldering their own electronics are rare and valuable.
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