I want to hear both PC and Xbox One/PS4 volume at the same time, because I like playing games and listening to music.The Xbox 360 dashboard had this functionality built into it at launch when I had mine - I assume it's still there? You could even access a shared library located on your PC.
I especially love doing this for Zombies, but I can only do it on solo, because I can hear PC and Xbox 360 volume at the same time, but when I plug in the Xbox chat cable into the back of the headset, it cuts off any volume from the PC. Also, sometimes I'm talking to friends on Xbox and I want to talk to them and play on PC, but still hear the PC volume.That's because the Mixamp (and any other gaming headset amplifier that I've ever seen) only have two inputs. Unless you can combine your PC audio with your console audio using an audio mixer box before running it into the headset amplifer, I think you're SOL.