Jlambrick...You say "I'm not absolutely sure what the frequencies are". All the more reason to get that Behringer. Its spectrum analyser (also called Real Time Analyzer, RTA) will show you what your problem is. No matter how you fix the problem, room treatment, equalizer, build a new room, understanding the problem is the first step. And, although equalization has theoretical faults, as Shadorne points out, in practice the benefits sometimes outweigh them.
So I say... get the Behringer as a spectrum analyser. Then see what equalization does for you. Trust your ears.