I have a Onkyo 6x80 watt dolby digital receiver. I would like to use it to power my 5.1 surround system plus two sets of speakers one in a different room another pair in my patio. If my 5.1 system is hooked up to the A system and the other two to my B system and I press A/B the receiver automatically goes to stero and I lose the sound from my rear speakers in the 5.1 system. What is the best way to get all the speakers playing at the same time. Without purchasing more equipment I do have a separate speaker selection system. Thanks for any suggestions. Tom