Formulas are great but you can only use them to get a very general idea. Real rooms are a lot more complex acoustically than most formulas take into account. Few allow for furniture, wall/floor surface type, much less the polar radiation pattern or source impedance of your equipment which is apparently important in determining room response. Art Ludwig and Linkwitz have interesting stuff to say on this topic and are worth a look if you are looking at your room. www.linkwitzlab.com and www.silcom.com/~aludwig if your interested.
Good luck,
Sincerely, i remain
Good luck,
Sincerely, i remain