I'm helping a friend with his new stereo (an Onkyo receiver) and in addition to the normal 5.1 connections, he has two sets of outdoor speakers he wants to connect (one on his back porch and another on his patio). The Onkyo receiver has an extra set of speaker connections for Zone 2. I tried connecting both sets of outdoor speakers to this one set of speakers inputs simultaneously. Everything seemed to work okay, but the unit shuts off after a few minutes of listening to Zone 2, perhaps because the protection cicuit is kicking in. Did I create a short circuit by connecting two sets of speakers to one set of speaker outputs? If so, what is the best way to achieve my friend's goal of having two sets of speakers in Zone 2? Thanks.