How to combine 2 audio signals from HDMI
As I've known so far there aren't receivers that mix audio.
I want to mix 2 HDMI sources, lets say 1 is a PS4 and second is Xbox One, how would I mix them in 7.1? Mix the 2 audio sources into 1, is there a way of doing that? What is the simplest way.
I know that there are stereo mixers, but haven't heard of a HDMI one.
What is the simplest way of mixing both signals?
I think it might have something to do with modulating the signals, but I don't specifically know how modulators work.
I don't mind getting a receiver that can do that, if there's any.