Thanks for your purchase and kind comments. I will try to offer some advice but you may wish to seek local support from your GoldenEar dealer.
You are dealing with a room problem, not a speaker problem (which means any speaker producing bass in the room from the same position will have the same issues). A pair of Triton Twos with their two 1200 watt subwoofers in that size room will produce more low bass than anyone could ever want (or maybe even stand) - the reason they are not is you are sitting in a "null" where the bass is being cancelled. Your room dimensions are the first clue - equal wall lengths means a much more significant peak and valley bass response due to the magnification of the room nodes. You are apparently seated in a valley, with peaks off to the side.
You can try some placement adjustments with the towers: closer to the rear wall, closer to the corners, etc., and see what the effect is in your listening area. Adding an additional subwoofer in another location MIGHT help reduce the peaks and valleys a bit, but in my experience probably not. If you do wish to add another sub in the room, the best way to do so is to keep all your settings the same but change "Subwoofer?" to "Yes". This will direct LFE-ONLY to the subwoofer (which will only be active on movies and music with a ".1" channel). Adding a subwoofer for more than that will cause all sorts of headaches regarding sub placement and center channel bass reproduction.
Speaker position changes, room acoustics treatments and electronic room correction are your most likely problem solvers for your situation.