Since no one has chimed in, I'll just give the results of my two hours of "fiddling."
I set up my cords in the practice room so I could get about 25 feet away from my rig. I made a number of adjustments to the amp, while playing both my P and J basses, both of which use Fender tapered rounds. I had the P's vol/tone settings basically full on, but I had the J's pickup vol/tone settings modified a bit. I also pulled the rig about 14 inches from the wall so the rear porting would get some room to work.
Getting out where the "throw" occurs changed everything.
Instead of the muddy sound I was hearing near the rig, I was getting great punch and low-end standing in front of the rig about 25 feet out. I tried to focus on settings that would work for regular finger striking, rather than slap or pick, although I hope to get these settings in due course.
I worked on a setting for a more "traditional" bass sound, and one with a pluckier, more modern sound. Using the MF Low and High settings and the two filters, with some minor adjustments to the regular eq settings, made this pretty easy. Getting away from the two cabs got rid of the mud, even on the more "traditonal" eq settings. The transient response seemed pretty good, even on quicker passages.
If someone has this or a similar rig and wants the settings, I can send them to you if you want. Shoot me a PM. If not, I'll report more when I do some more research.
All-in-all, though, it looks like I am well on my way to getting the sounds I want from this new rig despite my initial misgivings. I can't wait to try these settings with the entire band to see how they work in the mix.
