When I plug in my Infinity BU-1 subwoofer, I hear a constant hum. I am connecting to an Onkyo TX-SV343 receiver. I connect the SUB-WOOFER PRE OUT on the back of the receiver with the LOW LEVEL INPUT on the back of the BU-1 using A/V cables and a Y Connector. What am I doing wrong? How can I get sound other than that constant humming?
Try connecting without the Y connector and see if this resolves the problem. This worked for me a few years back. Since you have two cables try the other if the first trial without the Y still produces the hum. You could have a bad cable. Let me know how this works. Best of luck.