said by printscreen:Odd. I have more than one inputs and they all work at the same time with no issues. I have the Line In into the sound board (from my A/V receiver), the microphpne input in the sound board (not used but device is active), the microphone from my webcam and a USB headset with microphone I use at times. They are all enabled and they all work when needed without having to go to sound and select any.
All different sources, and likely used for different apps. Line In and Mic are treated seperately by the audio chipset. The cam and USB input are both different chipsets.
OP is basically wanting to use two "Line In" inputs on the same audio chipset. It may be possible and supported by some audio card, but not on the standard chipsets I've used.