Will a new sub sound better than my Velodyne F1200?

Just got back from vacation. 

Calculating the amount of cubic feet in the room is complicated. Even ignoring the large openings that this room spills into, I'm at 3600sqft. I would have to post a picture. There are significant variations in distance on both the X and Y axis. For example, the front wall has a couple 6ft wide openings. One goes to a hall, the other to the kitchen. To the right of my listening position is a 5ft wide opening into the entry, and then there is a 5x5 hole in the wall into the dining. The Y dimension is a mix of walls at 22ft, 26ft, 34ft, and 39ft. The ceiling in the listening area is vaulted from 8ft to 12ft. 

I sit about 10 feet from the mains and 11 feet from the sub.

It turns out that my 12" sub is 100W. I'm beginning to think that it might just be too small for my room. In addition, I suspect the servo may be sacrificing dynamics for the sake of lower distortion in the lowest octave. If you play stuff with bass below 40hz, it seems pretty powerful, but it's the mid-bass that seems like it's behind. I imagine an impulse reponse looking kinda rounded I guess.

I find sizing bass to be a confusing matter. For example, with my Revel M106 speakers ONLY, I'm flat down below 50hz, but the kick drum and double bass are wimpy. If I use the SMS-1 to get the same response with my sub going, there is much more bass, yet the measure the same with test tones. 

My chain is Schiit Yggdrassil balanced into a Sonic Frontiers Line2 SE+ (with cutf caps, and a mix of 1960s Amperex 7308s and Siemens E88CCs). From there I fork single single-ended into the SMS-1 and balanced into a Pass XA30.5. My mains are Revel M106. I have the ports plugged on the M106 which clears up the midrange a bit and lets me have a little better control integrating the sub.

The data-bass link was great. I'm still going through it, but it's got me curious about the SVS 16 ultra models. I'm assuming the sealed model would be ideal for music, but a lot of people seem to prefer the ported version. I don't care if the enclosure is huge. The previous generation HSU 15 inch sub didn't measure out that great. I think the rest of my system warrants something better than the HSU. 

Update: Last night I readjusted the phase while listening to music (Six Blade Knife by Dire Straits) instead of using test tones. That made a significant improvement.

I'm convinced that multiple subs is superior, but I'm completely out of room on my front wall, and I don't have front corners to place the subs in. For two subs, I'd have to put one on the front wall and the other on the back wall or a back corner. I agree Bob, that two HSU units would probably be preferable to a single SVS 16.

I think one of my integration issues is that my mains aren't high-passed. With the ports plugged, they start to roll off around 80hz but it's a very gentle 5db/octave rolloff at that point, and then there is probably a 12db/octave rolloff around 55hz. There is a LOT of overlap, and both the mains and the sub show a big room node at 60hz. 

Does anyone have recommendations for good XLR high pass for my mains? I don't want the signal quality to the mains degraded in any way.

Well, I took a leap of faith and bought an SVS SB16-Plus. In short, it is a significant improvement.

My Velodyne F-1200 sounded very boomy by itself.

With a Velodyne SMS-1 in front of the F-1200, I was able to get the frequency response pretty flat, but things still sounded a little out of sync, or slow.

The SVS has built-in parametric EQ, so the SMS-1 was removed from the system. To tune the SVS, I had the SMS-1 output its test tones into my pre-amp (and therefore through the entire signal chain), and I used the SMS-1 microphone to then measure. I made EQ corrections on the SVS itself. This got me to a pretty flat response, though there is still a bump between 55 and 65hz (big room nodes there even adjusted -8db or so). I then used the kick drum on the Police's "Murder by Numbers" to fine tune the phase on the new SVS sub. I find this results in a better sound than playing a test tone at the crossover frequency.

Now the sound is a lot punchier where it needs to be, and the entire bass range is a lot cleaner. The 16 inch driver may be massive, but it doesn't seem to have any detectable overhang, unlike the 30 year old Velodyne design.

I have a strange room setup with a lot of cubic feet, but I'm not stressing this sub at all. At typical listening volumes, you can't even see the driver move. However, if you crank it up the volume and put on some music with serious low bass, hold on to your hat!

I am running my Revel M106 speakers full-range. I don't know if you can ever get an absolutely perfect integration of a sub and a monitor speaker running full range. You definitely want the sub playing the kick drum, which means there's going to be some overlap and the phase of the sub will only be perfect at one frequency. Nonetheless, I'm really pleased with the results. 

FYI, the SVS has 3 parametric EQ points. If you buy this sub, plan on using one of those to put a low-Q bump at 20hz to get the thing playing flat down into lowest octave and then into the mid-teens. So practically speaking, you're left with 2 parametric EQ points to deal with your room.