Some go through all this and get stereo. It's a common complaint but to connect it up, try HDMI and the Optical. Use what works.
Audio pass through is never assured to be HD unless the source is from OTA. This is not a Samsung thing but the industry that is trying to protect HD content and sets the rules on how HD works.
Guys I recently purchased Onkyo 3500 which I'm trying to hook it up to my existing Samsung D6000 46" TV. I want the setup in such a way so that when I play a movie using the USB Port of the TV the audio should come out to my Onkyo 3500 AVR. I think one option is to get an Optical cable.
But I also read that both the devices support ARC which is Audio Return Channel so I can have the Output of the TV come to my AVR using an HDMI Cable. However I don't see that happening using my current HDMI cable. The only problem I think is because the one I have is 1.3b Version. I also read on the internet but not sure that only 1.4 HDMI Supports ARC. Can someone help me on this?