I have a XLS 1500 and 1000. I recently purchased 4 speakon cables for these two amps. I cannot get any of them to work on either amp. I get microphne imput to the mixer and to the amps but they will send power to the speakers. I have tried all 4 channels and all 4 cables nothing works. If I connect wires directly to the outputs everything works fine. Can any one help?