Thanks for your interest in our VTF-2 Mk5 and VTF-3 Mk5 HP subs! I think the word lend is a good way to put it as room acoustics can vary quite a bit even with the same dimensions and placement. It's very much a YMMV thing. Given where you're seated in that room, I believe you may very well be able to go with a single sub for that room. The benefit is that you are seated up against the back wall, so that tends to give you a good amount of boundary gain at your listening position and you tend to not get as strong of nulls versus when you're seated out into the middle of the room. For the single sub I would just keep it out in front and maybe try to place it on the inside of the right speaker (between the right speaker and entertainment center) to see if that gives you a better mid-bass punch at your listening position.