MHRossing

I am relatively new to setting up electronics, and am having trouble getting my Klipsch RW-12D to produce sound. I am setting up a 7.1 system and have a Yamaha RX-V3800 receiver. When I test the speakers the subwoofer does not even produce the test sounds. It does turn however when plugged in. I have it connected via an RCA cable to the subwoofer out plug on my receiver. Can anyone give me suggestions on what might be the problem. I have a feeling it is a simple stereo setting issue but I cannot seem to figure it out. I have my front and center speakers set to small. Any ideas? Am I an ignoramus and just missing something easy?