Here are some screen shots of my sound settings. They match the setup instructions HRT sent me. See anything? Want to see something else?
I’ve gone down the RealTek control path and can’t seem to find a volume control panel. I can find the Dell Audio control panel and regular volume controls accessable through the speaker icon. It appears there are only RealTek drivers loaded. No simular questions or answers to my problems have been found in the Microsoft Community forums. I’m still googling it…
Thanks for your help so far. 
