Quote (AbDuCt @ Mar 22 2015 09:28pm)

Most people don't use audio cards any more. Most hardware is USB based with dedicated dacs over USB.

You're going to need to list a lot more information. Video editing is one thing since the software will define most of the build, but for audio we will need to know what exactly he is using or planning to use. Is he using midi controllers? Is he planning to do studio recording? Are they going to attempt to hook up a mixer and cdj's to it? Does he even have any gear or is he just point and clicking in ableton?

There is a ton of questions to be answered here. If he just needs an audio card for previewing tracks he might as well get a USB dac/amp and some bookshelf speakers or headset instead as they will provide better sound most of the time. If he needs to record then there is another slew of questions.

Also you have to make sure you are building the computer correctly. A bad ground can introduce a fuck ton of noise into a recording/playback.