tomic601 wrote: "for those of us with powered bass bass and EQ built into our mains, when adding a sub w EQ we get most IF not all the benefits of swarm..."
Are you describing a system with two fullrange equalized main speakers plus an equalized sub, which overlaps and augments (rather than replaces) the main speakers down low? If so, then yes that can definitely be competitive with a four-piece Swarm.
Warning: The following three paragraphs go into some technical stuff. If you don’t like technical stuff, please skip them.
A single equalized sub can give excellent results in the sweet spot, but often makes things worse outside the sweet spot. This is because the room-interaction peak-and-dip pattern is specific to that sub location and that listener location. Thus in other listening locations the peaks and dips will have moved around, such that in those locations the EQ could be boosting a peak and/or cutting a dip.
With a distributed multisub system, the multiple dissimilar peak-and-dip patterns sum at any given listening position, and therefore tend to smooth one another out. The only way they could fail to smooth one another out would be if they were identical, and that won’t happen unless the subs are all in the exact same location. If there is still a significant residual peak or dip, chances are it’s present throughout the room, and therefore is a good candidate for correction via EQ. In other words, a distributed multisub system actually makes EQ more effective (though less likely to be needed), because its benefits are more likely to extend throughout the room.
And "smooth" bass is "fast" bass, because it is the in-room peaks which decay more slowly than the rest of the bass spectrum and therefore sound "slow". Yes we can hear the difference in perceptual "speed" between different types of subs, but that goes back to which is creating the biggest in-room peaks, and it will be the sub that is loudest in that region.
Anyway imo you are WELL ahead of the game with three distributed, equalize-able bass sources. Earl Geddes, whose ideas I use (with his permission) in the Swarm, later moved to using three independently-equalized subs, with the equalization settings generated by his own proprietary algorithm from in-room measurements. I’m no Earl Geddes, so I’m still using his first-generation four-piece distributed multisub concept.
I wish I had sufficient economies of scale to do a $1500 budget-Swarm system... alas, not even close. The labor cost on the boxes doesn't go down significantly as the box size decreases, and labor is my biggest cost.
Duke