Merging two jack audio sources from guitars and BT from PC into one source

Question

I am wondering how to solve this problem: My flatmate plays bass guitar and I play electric guitar, we live in a block of flats so we have to use headphones. We would like to play together, ideally with 3rd track as backing track from PC.

Is there any device which would allow us to merge output from our amps into one cable which we would latter split with jack splitter to two separate headphones?

Scheme of my idea: https://pastebin.com/qFZX2ipa

I have Behringer Uphoria UMC 204 HD which has only 2 Jack inputs (and some other inputs), I don't know if it will help because I haven't fully figured out how USB interfaces work yet, for now I can only plug in my guitar to it with JACK "Y" cable (it changes one stereo [output from an amp] to two mono paths [2 jack inputs in UPHORIA]) and then record it.

Answer 1

You need an audio interface for the PC with at least 2 instrument inputs to get the audio in to the PC - your Behringer should be fine for this.

Then you need some kind of DAW (or even basic mixer software) to let you play those two inputs along with a backing track and balance levels appropriately.

And then you need a way to get the output to your headphones. A simple headphone splitter will work here, but the better option is to have an audio interface with a range of outputs, so you can change your monitor levels for each listener as needed. Your Behringer doesn't have this - I think it just gives one headphone out.