Sure enough, but there's not much room for anything drastically different there. Why shouldn't the 20-31.5Hz average track very closely to the actual 25Hz number? Looking at 22 sealed systems on Data-Bass, they fall on average +/-0.5dB. At the extremes one system is 1.1dB higher at 25Hz than the average of the three, and the least is 0.5dB lower.
Our 117.8dB 20-31.5Hz average means we fall between 117.3-118.3dB at 25Hz.
With an Sd of 800cm^2, the three 15's will have to move between 37.6-42.2mm to make those numbers at 2m.
To check our work, we've got a rating of 107.6dB for 20-31.5Hz for the XS30. Give us the same window and we should be looking at 107.1-108.1dB at 25Hz. Same 800cm^2 Sd, the two 15's in the XS30 will have to move 17.4-19.6mm. With a 2" peak to peak spec on that driver (or 25mm one way) it's right on to expect 18-19mm of clean throw.
For what it's worth, I'm saying this Triax is a monster. Three high throw 15's with appropriate power and signal shaping in a nice small box. This is doing subwoofers right.
From all of the information given, it looks pretty safe to say that we're looking at LMS Ultra level excursion, or double that of the Power X series 15's. Approaching a different way, the +7.2dB per driver advantage of your Triax's numbers vs your XS30's numbers also confirms this.