Q: "I'm doing some basic mastering of a demo. Should I use the Normalize function in my software or invest in some compression plug-ins?"

A: Few mastering engineers rely entirely on the normalization function of a software DAW to adjust levels. Normalizing increases the gain of an audio file until its loudest point (or sample) is at the maximum available level of the system. While this has its advantages, and is certainly part of what happens in mastering, most mastering engineers feel that this process doesn't accomplish everything they need for level control.

One of the goals of a mastering engineer is to get the appropriate amount of level on a finished project (CD, DVD, etc.) WITHOUT distortion (while still sounding natural). Typical normalization routines just don't provide enough flexibility to accomplish this. Generally compressors and limiters are employed to make (hopefully) subtle adjustments to the dynamics, which can then enable the engineer to maintain a higher average level.

Occasionally, expanders are used to increase dynamic range. The level itself is almost not as important as the perceived level. This is where the art of using limiting and compression to help shape the levels of the song or whole album come into play and the reason that real people still man the helm of the mastering process - you can't push a button and have it happen automatically.

How you use a limiter and compressor in the mastering phase is beyond the scope of this article. That said, there are some amazing tools on the market that do a great job of bringing some basic mastering techniques into the range where just about anyone with a good set of ears can make significant improvements to the overall sound of his or her recordings.