Weird balance trouble on rear channels

[SageBug]

I just stuck my old amp back in and everything works as it should.

 

[Widg]

Not sure what you mean by "return" I'm thinking the wires coming from amp to crossover, correct?

Basically the wire where the Electrons [traditional] get back to the source.

My way of speaking electronics is getting a bit archaic. Ho hum...🙄