Looking to build a room, but

So our approximately 2200 square foot basement is unfinished and I would like to build an audio room. My primary goal would be 2 channel audio oriented for the best possible sound, but I am sure I would want to watch movies with the kids as well, etc.

I know of Rives, etc. and figured I would contact them, but what I have noticed is that there are an aweful lot of support beams in the basement (from floor to ceiling). More than I have noticed in other houses we have lived in (maybe I am just paying attention now). Anyway, I am fearful that I would not have to make a very small room to exclude having these support beams in it or, alternatively, a larger room with the support beams in it. Has anyone encountered this and if so did it make a big difference in what "could have been possible" if the supports weren't there.