All -
I've tested the REW with two different computers and am getting what appear to be mixed results. I am now using a Dell laptop with a SigmaTel audio soundcard that has a line in option. I'm able to get the SPL signal to register within REW and was able to generate this curve after a lot of messing around.
Granted, these are just computer speakers with a small subwoofer attached, but before I drag the computer to the theater room and try again there (my first attempt was unsuccessful), I thought I'd post this graph and see if this looks normal, or if there is clearly something I'm doing incorrectly. It could just be that they are fairly terribly configured, cheap speakers.
Shots of my settings are also posted just in case. My soundcard calibration file is also attached (two shots of the same things at different views - I think it looks fairly normal)
One thing I have noticed is that I do not appear to be able to run the feedback loop and the SPL measurements at the same time. I'm wondering if perhaps I do not have a stereo line in because anytime more than one connection is made on that input all results look very odd.
Thanks for taking a look!
Jason