As far as working on my volume, and EQ, and 'technique' goes... really? I'm a performing, working bassist..for 50 years.. I've worked with many rock and blues legends. I hardly think I need any tutorial in these areas. But thanks anyway.
Well, with all due respect, if that was completely true, you wouldn't be on here with vague questions and vague goals asking strangers on the internet how to achieve something that you can't even seem to articulate yourself.
When you're depending on the pro sound folks to be at your level of preparedness and expertise, and they are not, I can't imagine what would be possible from an on-stage rig to overcome that obstacle.
Well, the reverse is certainly also true. And honestly probably more common than the other way around. A decent sound guy can keep a great sounding band sounding pretty good, but even the best sound guy can only do so much with a band that doesn't have a clue how to achieve a nicely balanced stage sound (or just refuses to). And MANY MANY MANY bands simply don't have the skill to achieve a great stage sound or just don't care and want to do the ego trip "everything louder than everything else" thing.
When the guitar just by itself (or anything else, like drums, bass, etc...) sits on top of the entire FOH mix, the best you can do is try to get a reasonable balance for everything else and try to keep the vocals mostly audible. Honestly I think I might start offering "band coaching" services on how to sound good on stage, choose material, tighten arrangements, etc... it would be more for my own sanity when running sound than for the money.
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Anyway, back to the OPs issue.
I really think you don't know what it is you want, because in 6 pages you haven't really specified to the degree that anyone could offer really good advice.
BUT, I will take a stab at some possible solutions, based on your posts, others posts, and reading between the lines.
First, to describe your issue as I understand it, you seem to want a big, immediate, deep, clear, clean bass sound. Unfortunately, that does mean size, weight, and cost are going to be issues. No way around that.
The first option I would suggest, would be a custom build 18" sub, using the most sub focused driver you can get your hands on. I'm talking something with a response down into the 30s or even 20s. Don't skimp on cab size. Tune it as low as is feasible to get rid of any low mid bump in the response (that's what kills your tone and makes it sound loud, but tubby and cheap and annoying). I would pair this with a stout 3 way 2x10. You want to build this with a similar concept, but maybe with less emphasis on lows for the 10s, unless you want to be able to use it as a standalone. 2 10s, a 5 or 6, and a tweeter/horn. You probably want to get some skilled help with both cabs as it's clear this stuff is not in your area of expertise.
Then you run whatever preamp you care to (maybe your Pearce), into an active crossover (or use one on your preamp if there is one), and into 2 sides of an old school SS power amp, in the 400-600w per side range. Then you have to figure out where to set the crossover, but 100 Hz is a good starting point. The target would be to get a sort of "smack" from the sound, which is I think what you're missing and trying to achieve. Using a legit 18" sub should get a response curve that will get you along those lines.
The next option, is you might just be looking for a more traditional bass cab but with a lot of square inches. Something as simple as an SWR 4x10 might be a good place to look (or maybe 2 of them). Either the Goliath III or IV, or the Golight (but not the sealed Marcus Miller version). Using a pair of those, even at low volumes, should give you some of that immediacy you seem to be looking for. A Henry the 8x8 may also be a good choice. You could substitute the SWR for any number of other choices, but they have a really nice tonal profile and easily available for pretty cheap. A high end modern alternative might be the Genzler bass array 4x10.
Which leads me to my last suggestion, which would be something more along the lines of the Phil Jones stuff, or maybe one of the MAS cabs. Using multiple smaller drivers is going to get you a different sort of vibe than for instance a single 12 with a tweeter. The downside is the Phil Jones stuff at least tends to be heavy and expensive.
I would say if you try all 3 of those approaches and can't get close to what you're looking for, it's probably not possible.
But yeah, really you should try to be more descriptive about what it is you're looking for, because your posts have been vague as hell, and I only grasped as much as I did because I have a similar (I think) thing that I'm looking for, that I call "bottomless" bass, where the notes just have a snap to them, even down to B or A, and there's no "restricted" or stuff feeling in the low mids. It seems like that might be similar to what you're looking for. But you should also describe what gear you are using in depth, and also what kinds of music you're playing, and what sort of tone or tones you're after. Because even if you look at 3 "slapping" players, as on the SMV album (Stanley, Marcus, and Victor), they all have pretty different tones, even within that sort of same world.
So the more and better information you provide, the closer people will be able to get with their suggestions. But at the very least you should probably stop mixing cabs and stop raising them off the ground. Figure out which of your main cabs you like the best, buy a match for it, stack them on the ground, and then go from there. And maybe try a different head too, like maybe an SWR or an old Trace or something more boutique like a Euphonic, etc...
