There is a simple way by using a freq sweep test disc and a sound pressure metre, then you can test how your room responds to the tones on the freq test cd, put the microphone in your listening position and test each freq, it will give you a general idea.
I use a PC and a programme by XTZ and measure to room using a more accurate microphone, you measure in 3 place and the programme will show you the respone of your room.
My room is heavily treated, it looks a bit weird, but it's great to talk in, and presents a massive soundstage, it's not finished yet, but very good sounding.