Only thought that jumps out at me is that its a bit of an apples and oranges comparison.
First, a broken-in 2x12 cab vs. a brand new single 12 combo? As far as moving air that's as big a difference as putting the 2x12 up against a 4x12 to me, plus you're getting the low-end extension of the broken-in speakers. I just don't see a way you will replicate the sound and feel of a separate 2x12 with a combo - combos are a compromise IMO; you do them for weight, size, cost, or ease of movement, not because they are going to compete sonically with a head/cab setup.
Next thing is, why are we comparing the sound of one amp to the sound of another? They are different things and are going to sound, feel and react different. No shame in preferring a Marshall but if that's the sound you've hung your hat on don't go looking to replicate it with a Boogie. Boogies are their own thing, which is decidedly NOT a Marshall. Those of us that love them do so largely for that reason - freaking everyone sounds the same (Marshall) so its great to have a sound that is definitely not that. Even the "thumpiest" Boogie mode (EXTREME, which has zero negative feedback and more gain) won't sound like a Marshall, even as the low end loosens your bowels.
Some Mesa circuits will do that thing you describe. Try a Triple Crown or a Badlander. But it ain't a Boogie, so I'd say its either love that sound or move on.
True, all things in music are a compromise. Good points too on the response of a broken in speaker vs. a new one. For me, I don't really consider that breaking in thing a big concern for me, because I can easily rack up 30-40 hours of speaker time in 7 days, but your comment does indeed make sense.
I expected the Mesa to sound different. What I did not expect was that even when the bass knob is cranked the the low slider on the GE-7 is maxxed out, you still don't get a "thump" out of the Mesa on the bottom end. This is most noticeable on palm muted F#'s such as the into to Judas Priest's "Youve Got Another Thing Comin," but having said that, the Mesa does retain a very balanced tonal spectrum with plenty of midrange to easily cut through the mix.
So, what I think I have identified in this experiment is that I tend to like cranked bass EQ with a swirling, chainsaw-esque midrange that not only cuts through the mix, but the resonance (even from a 1x12 DSL40C) literally hits you in the chest if you are in front of the amp.
This is especially useful when playing with a midrangey bassist and it gives whatever song you are playing a much stronger and articulate bottom end.
Now,
@Mitch Pearrow SJMP has been in attendance at our rehearsals at primo in Riverside and I was running a DSL40C with a 107db Electro-Harmonix 12VR75 and I was up against our other guitarist's 100 watt Carvin Full Tube Stack. Now, this is no measure of sound quality, but let me say this. Our guitarist at the time (Todd) liked to keep edging up the volume levels. Everyone else responded in kind and the bassist was running an Ampeg Refrigerator, so we were so loud that Kurt the manager came in to see what we were running.
It was near the end of the rehearsal (last song) and I said "F*** it" and cranked my DSL40C (Master Volume was on 8 so I rolled on the FV30L) and I noticed Todd reaching for his amp's volume knob repeatedly. After that song he said, "Dude, WTF!!! I was totally cranked and you were killing me with that stupid ass Russian speaker thing you got on the other side of the stage!!!' He could not believe his 100 watt tube full stack was obliterated by my DSL40C 1x12 Combo.
Now, dick measuring contests happened occasionally, and that's one reason why we dropped that guy and moved on, so I am not saying this to look cool or whatever, but to be able to produce that level of resonance and never have it overwhelm the speaker with the bass frequency and still be able to dial in enough mids to rise up over that bass response, almost as if you were actually running tow amplifiers, is something that appeals to me.
That's not saying that the midrange tone of the mesa is not appealing. People who know me on FB have heard the short video we shot at rehearsal on Saturday and the Fillmore totally stunned everyone with it's punch and small packaging. There really is nothing I have negative to say about the Mesa Fillmore. Nothing at all. But, to my ears, it sounds thin in the mix and a lot of that has to do with how all our bass players seem to intrude into the guitar's sonic register with a really, twangy, midrangey kind of sound.
I get 2 hours of prep time on Saturday's before the student band assembles, and I frequently take this time to do a 2 hour warm up of various songs, riffs, etc. 2 weeks ago, I was jamming in the rehearsal space and the director came in and said, "Who was playing bass with you>" I replied, "Nobody." He was stunned and said, "Hit a chord," and I busted out the main riff to "Wicked Sensation" and he said, "Geez, that thing is pushing air like a bass!!! The pictures on my office wall were rattling, yet the mid range is cutting like a chain saw. What have you got in that Origin????"
Ya, OK, that's a cool compliment, but let me tell you that we have been playing out live and the bass player stepped on his cable and pulled it out of his bass for a minute, and when we went back and listened to the video they shot, my amp was kepping up the lower end to where it wasn't a night and day difference.
I like having that sonic authority in a live mix. and it really adds a fullness to the overall spectrum.
I'm not sure that I can shake that, Man...