Thanks for your post.
It sounds to me like you combined multisubs with EQ, and this is an excellent approach. The reason is, with distributed multisubs the bass is much more consistent throughout the room, so that when you equalize you are more likely to be addressing global (throughout-the-room) problems instead of addressing problems in one location but making things worse elsewhere.
I have heard it argued that a single equalized sub will be smoother in the sweet spot than a distributed multisub (3+ subs) system will be. But I don't know anyone who has tried it both ways who prefers the single equalized sub. Let me quote from someone who has experince with both approaches:
"Im 54, musician, assistant engineered & programmed synthesizer at the Sausalito Record Plant, been doing this since a teenager...
"My last room had the equivalent of about $6k worth of acoustic soffit installed to tame bass modes. Also heard the superb $100k YG Acoustics Anat Reference system (Yoav is a great guy, very down-to-earth, worth hearing if setup correctly).
"[Four small specialized subs spread around the room] exceeds the best sub performance I know of. You name the quality, its there in spades. Slam, low bass cutoff, power, etc. In pure musicality, pitch definition, transparency, realism, portraying differences in recording venues, this system probably sets the world standard. Ive played electric bass; the acoustic guitar I sold last winter was a Martin HD-28LSV (purchased from Dave The Ghost Caspar of the Oakland Raiders at his home in his trophy room). There's a nice Chang grand upstairs. The capability of [the multisub system] to flatten the rooms bass modes blows away the above described soffit of my last room. I had to leave that soffit behind.
"[This] subwoofer philosophy may seem strange to the uninitiated, who might view four subs as about three too many. To them I reply: Oh, really? Take a little peek over at the circle for room acoustic modifications & read the pages about people trying to control bass modes. [The multisub approach], IMO, completely eliminates the need for any other contraption to flatten your modes. The automated digital EQ of my Sunfire Signature sub was almost completely worthless (in performance) compared to [the multisub system], which costs less."
This is from a post on another website, and I can provide the link if requested.
My opinion is that if the question is going multisub vs equalized single sub, the multisub approach is superior. The best possible may well be an equalized multisub system, which sounds like what you did. But apparently the multisub system used by the guy I quoted above worked pretty well without equalization.