I am trying to set up a Samsung HW-m550 3.1 sound bar with the rear speaker kit SWA-8500s to a Vizio E600i-B3. It is all hooked up via HDMI ARC and I am getting sound from all speakers but it seems to be stereo? Set to bitstream audio and CEC on. Not sure if this is as good as it gets. My vizio sound bar with rear speakers system in the basement plays more ambient sound through the rear speakers like surround should, hooked up via optical cable. Just wanted to be sure I have my settings right.