Well Good luck, I will say, I hope its thats too. However, like I said, your response also follows a very steep bass shelf modeled on my computer. I would not have gone with such a large box tuned so low, I think that was a mistake. I do believe that was your problem. If room gain was more aggressive one might argue it would take care of that, but I seriously question if it could account for the over 6 decibles per octave you have below 30hz or so.
Also, the upper response of the Soundsplinter woofers, all of them, lumps up like yours, and then the inductance of the coil makes for a low pass filter in and of itself. I have been afraid to use these woofers because, even though they have lots of xmax for not a lot of money, the response doesn't look good. I felt that they were better suited to either a sealed box, car audio, or lots of EQ. I tried lots of different enclosures with the Sound Splinter woofers, and just couldn't ever get a response I liked the look of. I find it really interesting that your measured response looks very similar to the modeled response, with the acception of that dip, which I think is being caused by a room mode, but I'm not sure.
Maybe you already said this, but what is the crossover being used, and what is is it set too? A lot of what will fix the response comes from the crossover when I modeled it, so I wonder if that is being accounted for in your measurements or not.