I have a Realtek soundcard. I want to be able to record audio from my USB mic and from stereomix at the same time. Is this possible? I assume I need to tell my audio drivers that input is coming from usb but the control interface for my sound card doesn't give me the ability to do that. Any advice would be much appreciated
No, it isn't possible. The entire structure of Windows audio permits only one audio input device to be selected at a time. You can't even do it with a mic plugged into the RealTek. You can select recording from mic, or from the line in, or from the Stereo Mix, or... but not more than one. There just isn't a mixer in that path.