I am running a Yamaha RX-V663, to a JBL BX63, to a Nad 2155 stereo power amplifier to my JBL B380 Sub. When I connect it all i get just a hum from my sub. I have tried to do the test tone from the receiver and all my other speaker get it but my sub. The connections I have from the receiver are RCA from both Sub 1 and Sub 2 to the main input on the BX63. From the BX63 LF OUT (normal) to the Nad 2155 main in Right. Setting on Nad 2155 are 4 Ohms(normal), bridging On(mono) and soft clipping off. Then on the A Terminals connected to both +'s then to my JBL B380 Sub. What am I doing wrong? Any help please.
