Matt you are correct on trying to do room treatments via internet room measurements is risky at best. It seems like there should be someone available that has room measurement software that can actually map the room to figure out where the nodes are from a frequency perspective. This would be the best starting point since you could then move your speakers around and re-measure then add treatments. Do you have any audio clubs in the area? They are a great source of information and help.
As I mentioned some time ago room treatments should be additive and have a "do no harm" mantra. You can spend thousands chasing acoustics and may never totally resolve your issue. Take everything out of the room, work on getting your speakers sounding decent by trying various locations, then add treatments.
As I mentioned some time ago room treatments should be additive and have a "do no harm" mantra. You can spend thousands chasing acoustics and may never totally resolve your issue. Take everything out of the room, work on getting your speakers sounding decent by trying various locations, then add treatments.