Hi KSTx,
Be sure you shove the 1/4-inch phone-to-RCA female adaptor all the way in and make certain it makes good contact. It should sort of click when it's properly seated. Rotate the 1/4-inch adaptor to ensure it's not loose.
Go into the AV receiver's menu and be sure the subwoofer output is "ON". INcrease the sub output level to +2 dB. Turn the subwoofer's own volume control to about halfway.
You can verify if the subwoofer amplifier is working by inserting just the tip of the 1/4-inch phone adaptor--you should hear a loud buzz from the subwoofer.
Regards,
Alan
