I am trying to use the XLR outputs on the 976 to two Behringer 2031a TRUTH speakers. I just want to use these as fronts. Do I have to unplug the front rca output connectors or can I use both XLR and rca simultaneously? I can't seem to get any sound using just the XLRs ? The speakers have built in amps and power up fine. The manual states on page 21 "If necessary, you may use a combination of balanced and unbalanced connectors " I was using just rca's before without a problem. All the XLR cables are new and are high quality.

Thank You.