As fredk mentioned REW seems to be the cheaper but harder to learn product for learning the frequency response at your listening position. A popular bass management device to use with REW is Behringer's Feedback Destroyer. Others include the Audyssey based device sold by SVS and Velodyne's SMS-1.
Using a Radio Shack SPL meter and a DVD of test tones can give you a rudimentary look at what kind of FR you are getting at your listening position once you plot out the points. You will obviously lack decay information that REW can give, but at least it's a start.
