Mix Mastering - Skills of Paul Bryant and how he works on the stereo master, balances treble and bass, volume of the tracks and makes the CD sound "more expensive". Use of specific mastering person who is an expert in the area.
If you've been following Gearwire's visit to Boiler Room Mastering, you know that Collin Jordan doesn't have any lousy gear anywhere near his mastering suite. Here, he shows us his jewel from Crane Song, the Avocet Class A Studio Controller.