Turned Off My Subwoofer ... And My Speakers Sound Great

Or sometimes more is more. Your problem was you had a sub. All rooms have problems with bass modes, and the smaller the room the worse the problem. Unfortunately you went for the proven to fail approach of trying to suck up the bass with room treatments. The proven to succeed approach is four subs. Don't need to be big, especially in such a small room, but the small room only makes it more essential that you have more bass sources.  

The results you were looking for, they do indeed happen when you get a distributed bass array. Do a search. Study the system. https://systems.audiogon.com/systems/8367 Look for comments from Duke and Tim. Everyone with a DBA will tell you its the way to go.

perhaps the treatments negate the need for one at all.

They sure do reduce the need, yes.  By reducing the mid and treble energy in the room they can restore the bass/treble balance.

Even if adjustments need to be made on the sub, such as more futzing with the x-over, it seems to be a lot of work for a small return.

Often true. I've never been against subs, but the road to great sounding subs is fraught with peril.

Miller
Serious question.
Do you think a room the OP,s size of just 10x9x8 could handle a DBA or even two subs?

@millercarbon ... trust me, it’s way too tight for a DBA in my room. As I read the comments here and think about what has happened, I’ve concluded that a subwoofer is not necessary in every application where a 2 way speaker is used. That was a mistake on my part.

Plainly, room size and treatment play a significant role in subwoofer effectiveness. Sure, I could run the sub in parallel from a second preamp out, but all that does is duplicate the signal going to the power amp and eliminates the xover altogether. Since the Pulsars go down to about 41 Hz, bass is plentiful for me (generally, no low Hz organ notes in my rock/jazz listening). Thus, running in parallel wouldn’t seem to improve things much.

So, I’m back to square one. I’ll keep listening without the sub for a while and, if this sonic improvement holds up through various genres and recordings, then I’ll likely sell the sub. It’s a very nice JL Audio e110, so I don’t think it should be too hard to move.