abefroeman,
Just want to share my experiences. I was really excited to do a dedicated stereo room recently. It is an acoustical nightmare unfortunately. Its larger than your room, not very big, but at least rectangular.
Ive corresponded with probably 30 emails with a couple of knowledgable people. I bought 300 lbs of the best acoustical treatments I know of, on the used market. (10x HF Mondo Traps). I also have a curtain in the back, which does hide two of the treatments. Typically, they say its the front wall that benefits the most. Some persons, like Ethan Winer, use some insane number of treatments, I believe over 40.
Its still better, but treatments are not necessarily miracle workers by any means, IMO. I am already foreseeing doing a very serious downgrade in speakers now. Im just taking my sweet ol time before I see my beloved speakers depart. Unfortunately, my home is no longer worthy of my speakers. (But at least my HT is taking to the steroids very well
)
*Some folks would say a square room is just not worth it, no matter what, period.
I know you obviously are already, but proceed with caution before spending a lot on treatments. I'm sorry about the bad news.
See what you can pull off in the larger room.