I agree with Darren. You must get a Radio Shack SPL meter. (Check B&H photo for ~$35.00 shipped under brand name ATI). I bought my BFD off of ebay for $66.00. It took me a day and a half to get the setup running right with Room EQ Wizard, including MIDI. After letting REW set up the filters automatically through MIDI several times, I quit using it automatically. I was able to use 4 or 5 filters manually to get the same approximate response curve that you see Darren has posted. It works. At a bare minimum get a SPL meter to have some reference point.

Chuck