REW is much easier now if you own a laptop with hdmi output. It is a steep learning curve and a bit expensive initially to buy the mic and soundcard if you don't have hdmi. I dabbled with it off and on until the HDMI support came out and now I can get the graphs quickly and it is invaluable for subwoofer calibration. If you get a Umik-1 microphone they provide a sensitivity spec so when you load the calibration file you don't have to mess around with built in spl meter before taking a measurement.
