First of all, welcome to to the forums. Second, most people just plug the audio outputs on the computer directly into amps. Some people run them through a head unit and then to amps or just use the amp in a head unit. Some that are big audiophiles like to run them to processors first using either the analog or digital outputs on the computer. If your just a person that wants some sound then I would recommend just plugging the computer directly into the amps and then adjust the gains on the amps correctly. I would also recommend using a 3.5mm male jack to female RCA adapters then run quality RCA cables from there. It's still pretty inexpensive and will usually have less interference because most automotive RCA cables are shielded and pickup less interference. If you need any more help I'll be glad to help. There's many people on here that can provide you with pretty much any information you may need. Be happy if Soundman98 sees this post. He's a pretty reputable source of information regarding car audio.