Ha-Ha!
Well ya done good so far, 55! Man, if I could go back in time and start with a sub similar in price and performance to the LFM-1 EX, I could've saved myself A LOT of money
I do remember when I got my HSU VTF-3 MK2, which is very similar in design and performance to your new Outlaw. I had a similar "oh my god this is so awesome!" response, so I know exactly where you're coming from
Enjoy the heck out of it! That's the best advice I have to offer at this point
Don't get too, too hung up on "where to go next". Just enjoy your new sub for a little while. You've earned it!
But yes, ultimately there are still improvements to be had - although you certainly shouldn't expect them to be the same huge improvement as going from a HTiB sub to a REAL sub like your Outlaw! No, improvements now are far more subtle.
There is, of course, the "crawling for bass" trick. But you mentioned that you have several potential seating positions in your room. The "crawling for bass" technique will only let you find the rough position where the bass is the most smooth and even and flat for one seating position at a time. So even with that technique, you'd have to move the sub several times and try to find a spot where the bass is roughly even and flat and smooth for multiple seating positions. That could be rather difficult!
Instead, if it were me, I'd really only worry about the primary seat and maybe one or two other often-used seats. With a single sub, there's no sense in trying to find a position in your room that works nicely for EVERY seat - it just isn't going to happen. But crawling for bass for two or maybe three seats isn't out of the question.
It's great that you got a GRAMMA isolation riser! I wasn't sure if you had included that in your budget, but I'm super glad that you did! You should try listening to your sub with it sitting directly on the floor and compare it to how it sounds with it on the GRAMMA. Not only in your theater but also in other rooms of the house! I think you'll notice just how much of a difference the GRAMMA really makes if you do that. There's nothing so convincing and hearing it live for yourself!
And there's nothing wrong with your brain

Once you get a taste of TRUE bass performance, it's only natural to want to see just how far you can really take it! A second LFM-1 EX - properly positioned in concert with the one you already have - could certainly improve the evenness and flatness of your frequency response at multiple seating positions. With EQ alone, so long as you aren't sitting in a bass null, you can achieve pretty flat frequency response for a lone, "sweet spot" seat - perhaps luck out and get similar response at a couple of other positions. But to get even response at multiple seats, you pretty much have to use multiple subs.
So it's perfectly OK to want a second sub! After that, like we talked about, I think the next logical step would be to really go whole hog and go for a pair of stellar subs - but the jump in price is going to be substantial! In all honesty, that's a good thing. You shouldn't think of it as needing to spend A LOT more to get great bass. You should think of it as a situation where you already got great bass for an amazingly affordable price, and to eek out any sort of improvement, you have to spend A LOT more, meaning that you really did spend your money wisely!
For EQ, I'm certainly impressed with what Audyssey has achieved with their newest MutlEQ XT32 with Sub EQ HT. If and when you buy a new receiver or pre/pro, I'd certainly aim for one with those included. That said, right now, MultEQ XT32 with Sub EQ HT is only found on the more expensive models. Onkyo's got it in their TX-NR3009 and above, and in their sister Integra models. And Denon's got it in their AVR-4311CI. All are fairly pricey - though not insanely expensive
The other options are outboard EQ solutions. Automatic options include SVSound's AS-EQ1 at $770 and Velodyne's SMS-1, which is on sale for $500 right now. And then there's the manual Behringer Feedback Destroyer for around $100.
To be perfectly honest, I'd choose the Velodyne SMS-1. While the BFD is a tweeker's dream and the price certainly can't be beat, you can easily wind up driving yourself crazy with the thing! Furthermore, you really do need a high quality, calibrated mic to use it properly, plus the proper software and knowledge of how to use it. While the SMS-1 is a $400 jump up in price (and more when it's not on sale - regularly $750), you get a decent mic included, plus you can either just have it do the EQ automatically, or you can manually control 8 bands of EQ yourself using the included software. It's a pretty nice solution and enough to dial in almost any sub in any room quite nicely. It's not the be-all, end-all by any means, but it's basically what any beginner or intermediate user should hope for, IMO.
At $500, it's not an impulse buy, but it's still substantially less than a whole new, top-line receiver or pre/pro!
For now though, I think you should just enjoy what you have! Focus mostly on your primary seat and do the "crawling for bass" trick for that seat only. If and when you really start aching for a small change and improvement in your bass, it's basically going to cost you around $500 - either for a second sub, or for the SMS-1
Enjoy!
