You mention MC16 here. Is this the version you have? I do not quite remember since when we fixed the audio issue related to HD vs. SD channels. We made some improvement in MC, and the author of LAV audio decoder filter made some improvements in that, and the problem was solved.
If you have MC16, you can try installing MC17. If you want to keep using MC16, you can install AC3Filter and choose that in MC for audio decoding.
Sorry to have introduced some confusion here.
I download and installed JRiver Media Center last week, I see now that it was version 17, and that is the only version I have ever installed.
(When you asked about "Red October", I knew nothing about that so I viewed the JRiver wiki in which I read "Red October Standard -- MC16 automatically downloads, installs, and configures known good versions of LAV Splitter, and ffdshow. We build the graph and don't allow anything else. This results in video playback that just works. " At the time I posted I hadn't realized that the current Media Center version I was using was 17. "MC" as in "MC16", duh!)You may be on to something though where you mention this... If you want to keep using MC16, you can install AC3Filter and choose that in MC for audio decoding.
Given that I heard audio (2 channel obviously, that is all I use) on both receivable ATSC channels in SD, could it be that the HD channels are using a different decoder due possibly to 5.1 channels being present, and that's why there's no audio routing to my standard 2 channel output driver/device? That would actually make sense.
If so, how might I modify any decoder to insure that all standard audio feeds from the incoming signal be routed exclusively to my 2 channel output device? Aside from being able to select DVD audio tracks in VLC Player I hadn't considered that default audio a from a TV tuner could be routed incorrectly.
Thanks for you attention on this.