Snookboy
Here's the diagram (from the REW help file) for the hookup to your soundcard and receiver and BFD.
Notice the adapters in and out of the soundcard are both 1/8
stereo. but you only use a single channel (either left or right) in and out of the soundcard. Be sure to select the same channel in REW (left or right) that you have the cable hooked to. Normally everyone uses right. You also use the same right channel for the soundcard calibration routine (that you only do once and then save the file).
I know there is only one line in and one line out on your soundcard - but they're both stereo with two channels (Left and Right).
Yes unmute the wave.
If you don't like those heavy 1/8" stereo to RCA adapters you can get a cable type like this:
It's still a stereo 1/8" to two RCA connectors.
Still confused?
brucek