Maybe hit him up and see what you could work out for price and shipping. Doesn't hurt to ask.
I've not played through the Jacks, but I did get to play through a stack of four Omni 10s (Jack predecessor) once. I don't think that a Jack-stack would have the kind of bass response you'd expect from a sub but, if you like the one you have, two -- or three -- should, in addition to being louder overall, give you some more reinforcement in the low frequencies through coupling. On top of that bit of "free" bass, you will have more cab-headroom with which to play around with EQ -- adding some low frequencies or cutting some upper frequencies to make the sound relatively bassier. I'd still expect it to be a fairly bright, open, and not-super-deep sound overall, but you'd have more available bass and a more full "default" sound than you do now.
If you feel comfortable sharing, Charlie, what was your opinion of them -- or of the BFM Jacks in general? I know that they're reputed to be mid-forward and not have a ton of low end, but what do you think of stacking them with the OP's tone goals in mind?
That can certainly be the case, but, in my experience, it's situational and depends on the equipment and how you go about it. The MAS 8"-based cabs, for instance, have a -3 dB point somewhere in the 30s (lower than any full-range bass cabs I'm aware of except for the Acmes) and they are some of the clearest, least muddy cabs with substantial deep content that I've heard. (They remind me of little versions of the uber-subs I heard at a DJ shadow show more than anything.) They are a rarity, though, and I'd rather hear a rig roll start to roll off at 60 or 80 Hz than hear deep-bass-done-badly.
Too, sometimes the boom and mud happens higher up -- even in the 100-250 Hz range -- sometimes a small cut there can clear things up -- and isn't always the fault of the deep bass (though sometimes it is).
Finally, if you're doing deep bass, there is the ubiquitous HPF recommendation -- even if you just filter out the stuff below 25 Hz, it can make a significant difference in clarity with some amps and cabs.
Yeah -- I have cabs that I like but, for a certain kind of sound I bet these would work really well (and go quite loud with an amp with limited power). If you've got an amp that'll do it, three good 12s is a potent rig (though I know OP said that he doesn't need to go loud right now -- maybe later at his gigs sans PA support, though).
