I understood, and was hoping he'd take the M9...
Your wish was granted last night. The room represented every anticipated horror, too. Concrete floor, circular corrugated steel room with a metal cone ceiling and NO baffling whatsoever.
So without even trying anything else, the first thing I did was set voice 5 and drop the bass control to about 10:00. It was amazing. Except for the natural reverb of the room, it was really quite tight and controlled. Nice big sound, but still maintained a lot of focus down low. Exactly as I'd remembered it from last time I did this. I even went for the full brutality... played away from the bridge pickup, and in fully blended mode. I did eventually favor the bridge pickup, but most of the time, it was fully blended. I also made it a point to move my right hand around a lot, and even played way up over the fingerboard during a ballad.
The bass was my Sadowsky ash/maple/HC JJ5, so I know I'm getting some focus from that, but even that only goes so far.
Also, again, the rig was the Mesa M9 and a Series 1 UL310. For those not familiar, the UL310 is the second most "scooped sounding" cab Epifani makes, next to the UL210... at least IMHO... so I was not getting any extra help there either.
As a side note, I never got around to switching to the GEQ and trying it. Sorry Alan, but maybe at least some good news is, I never needed it.
Here's the best part, and I SWEAR this really happened, and I SWEAR I did NOTHING to solicit it... some random guy actually approached me and told me how clean and clear the bass was, and even specifically said "not muddy at all". I don't know what "qualifications" he had, but really, it doesn't matter. If he was highly qualified (sound guy, musician) he'd know enough to be accurate. If he was just some random guy that loves to catch bands at bars, for it to have stuck out enough to be that significant to him, still says a lot. Win/win.
So the bottom line is, I'm gonna' stand my ground and say, with the usual IMHO qualifier, the low end on this amp IS totally controllable, and as I've said before, the EQ design on this bad boy is deceptively powerful and flexible despite the few number of controls. I maintain it's just a matter of truly understanding how it works, thoughtful exploration/experimentation, and not being afraid to use certain controls even if they have a strong characteristic.