I am having difficulties with upmixing some of my stereo and mono movies. I have a 7.1 setup and an HK AVR 2600. I am doing this through a pretty powerful laptop with HDMI. Some 2-channel feeds will spread out beautifully to all channels, but most will stay on the Left/ Right and Center channels with nothing on the other four. What is puzzling is that that audio path shows a conversion to 8 channels, and, even more confusing, the AVR shows 3.4.1 48Hz PCM, but nothing is coming out from the other four channels. The files are generally mpg ‘s, sometimes packaged in a mkv but not always. Codec seems to be the same for all. I am using the JRiver mixing engine, and in fact all other files upmix very nicely. Does this have anything to do with the way the HDMI connection and the AVR talk to one another? It doesn’t seem like an actual JRiver issue but it doesn’t hurt to ask.
