The inSync reader prefaced this question with a plea for understanding because he's new to all of this. Of course, we get a question just like this every week or two so I think there's more than a few confused people out there.

"What is the difference between saving an audio mix to CD and actually mastering the CD? In other words, what happens between the final mix (which should already sound the way you want it to, no?) and the professionally mastered CD?"

This question basically asks us to define what mastering is. Handily, we've already done that and you will find Mastering in our WFTD archives. Please read the definition that is there (in general we encourage everyone to take the time to look up our referenced words. Many of the articles take on a whole new depth when you really understand the jargon involved). The question about whether material should "already sound the way you want it" is very valid. Ideally yes, and most people who produce CD's at home are doing a lot of what we used to call "mastering" without being specifically aware of it. But half of the point of real, professional mastering is to get an objective set of ears on the material so critical decisions that can effect the overall effectiveness of the recording can be optimized. Quite often projects are mastered (or even mixed) differently for radio, CD, and tape releases. There is no one right answer to the mastering question, but in general you can think of it as a potential way to eek out that last 1% of quality you missed in your recording or mixing. When you have the budget it is a highly recommended practice.