Im looking to build a computer for recording and listening for a friend, we were jamming today and got a noise complaint. I want to build a computer that can mix three tracks, Guitar, Electric drums, and bass. The way I see it with my limited experience with recording is there is two options. Option 1 would be to have a PA that would mix for us into one output to a computer or build a computer with multiple sound cards that would allow multiple outputs and input. We would need 3 inputs for the instruments and 3 outputs for headphones. I have built multiple gaming computers but never did a build like this before. I am thinking that the multiple sounds cars is the best option because we will be able to have multiple tracks and avoid buying a mixer and can mix in pro tools garage band whatever we want when we get that far. Also are there any products out there that can do this for us. I have done a couple google searches and came up empty. The only computer I have access to for this project would be a 2010 mac book so what is the most cost efficient way to go about what we need.