Here is my wild arse guess....
I don't know what the cu ft is with the Triax, but assuming it is close the Submersive I would think that the Triax would have around 3db's more output at most frequencies.
My thinking is that it has 1 more driver. If you double the amount of drivers AND double the amount of power you get an increase of 6 db's. Well, the triax has one more and also has more power otherwise that 3rd driver would be just a 1.5 db increase (Submersive has 2400 watt amp, Triax has 4000). But, are the Triax drivers better than the Submersive? Possibly I don't know.
So, I think 3 db's more is a safe estimation.
Now, the JTR Cap S1 has pretty much the same output as a Submersive, and the Cap S2 has 6db's more than the Cap 1S.
Throw all that together and you get:
Triax = Submersive + 3 db's
Cap S2 = Submersive + 6 db's
Still, no commercial sub compares to the Orbit Shifter:
Orbit Shifter = Cap S2 + 6 db's (20hz and above)