Yeah, I'm new here, 1st post, yada yada, cut me a wee bit of slack. So long story short, I finally got lucky on CL, and after a 13+ hour round trip arrived back home with a pair of jbl 4507's and a pair of 4645's. When I had time to dig into what I actually had, the magnet assembly was totally gone from one of the 18" 4645 drivers, and the other 18" is apparently a generic non jbl driver. Bummer.

On to the 4507's. 2445J's mounted to 2380's on top, sounds fine. I figured these probably had 2225s in them, but seller told me they had Altecs in them, turned out to be a good sounding pair of 3156's. Further inspection found a 3110A crossover in one and a 3115A in the other.
Battery of questions, if you don't mind.

1. find 2242H drivers for the 4645 cabs? (dbx 234 a decent electronic crossover for this application? x-overed at 80-100hz or so?)
2. I had planned to put a pair of jbl 2226h's in these, but to be honest the altec lansing 3156's sound pretty DAMN good, thoughts on which are better?
3. When I saw the the crossovers installed, I figured they were 3115A's or maybe 3110A's, turns out I got one of each. Its my understanding that the 500hz is the preferable crossover point, or does that depend on my keeping the altec 3156 or switching to the jbl 2226h? I ain't rich, should I sell both on fleabay and beg here for a schematic for this configuration for a fixed 700hz crossover?
4. any improvement going to 2446js over 2445's?
5. any other input or advice appreciated.

thanks much,
RCAdog