I just did an impulse of my room :(

Ok awesome. Well it looks like both the SPL meter and the Behringer measurement mic are both $50 online (RadioShack and MusiciansFriend, respectively).
 
I think you need the spl meter to check the output level. In the graph you have a 70dB reference line, and with the spl meter you set the volume until you match the reference level. Anyway You can use room eq wizard without it..
 
Is there any download link for REW besides that forum? They really don't want people to download it with that mess of a registration that won't allow this and that username :p

Edit:
Oh nevermind, the bugmenot plugin was acting up :)

I hope this program works better than RMAA. That program needed some RIDICULOUS amounts of gain for the mic to get an "acceptable" signal. I had my ECM8000 with 65 dB of gain and my speakers almost to full volume, and still RMAA said the signal is too low :S
 
Ok awesome. Well it looks like both the SPL meter and the Behringer measurement mic are both $50 online (RadioShack and MusiciansFriend, respectively).

Go for the Dayton mic, not the Behringer. They come with a calibration file for every individual mic. Not a generic one like the Behringer.