I just tried the tone test again, and it's pretty much the same as what I found in the old post, except now I'm finding the passive channel to have lower gain than the active, which is making me crazy. I really don't think I wrote down the wrong volume settings when I did the first test, but it's sure possible. It's either that or my passive channel has lost gain. (?!) But regardless, here's what I'm hearing. Try this with your bass and see if yours acts the same.
First, we're assuming that the center detent positions on the active channel's eq is flat. (It doesn't matter where the 'frequency' knob is set in this case.) So what you're doing is adjusting the passive channel's volume and tone so that when you switch back and forth between channels you're hearing the same volume and the same amount of lows, mids and highs - so there's almost no difference in sound at all when you switch back and forth. Just to get a basic start, the open strings work fine using open E to match the bottom end, A and D for mids and G for highs.
Here's what I found:
With the active channel set to 1-1-2.5-6-6-6-6
The passive channel sounds the same at 4-6-6-4
With the passive channel eq's all on 10, channel volume still at 4, the gain on the active channel has to be raised from 2.5 to 3 to match the volume, but now the passive channel is noticeably brighter, so what matches to me is:
Active channel 1-1-3-6-6-6-6
Passive channel 4-10-10-7
With the passive channel at 4-1-10-1 or 4-2-10-2, it has very noticeably less bottom and top end than the active channel set flat. So if 1-10-1 or 2-10-2 on the passive stack is flat, Then the active channel has a big built-in mid scoop, which it sure doesn't sound like it does to me. I'm prone to believe that the active eq's centered is flat(ish).
This is pretty much exactly what I found before, except I noted the passive channel volume to be at 5 and the active channel 6, meaning I was getting more gain out of the passive channel. I really feel like I must've reversed those two.
This is all VERY inexact as I'm just using my ears, but I'm interested to see if you guys get the same thing. We've got a couple week lag in gigs coming up so Im going to really try to drag the head down to the studio for some tests.