Not to be confused with mixing, music mastering is the manipulation of one stereo audio wave in an effort to achieve an improved overall sound. Music mastering goes by many names: CD mastering, Audio mastering, Digital Mastering. No matter what name it goes by, it always has the same definition. Music mastering is the last creative step before CD duplication/replication the last chance to improve your recorded music and take it to a higher level. Mastering is to your music what a glamor shot picture is to an ordinary photograph. The same way a glamor shot makes an already attractive person look flawless, music mastering makes an already good song sound great.
The music mastering process consists of four main basic components:
Noise Reduction consists of various actions taken by the mastering engineer in effort to eliminate any noise present in the track. This noise may consist of pops, crackle, hum, or hiss sounds.
EQ consists of various actions taken by the mastering engineer in effort to create an overall round, warm, and balanced sound in the track. Punch and clarity can sometimes be added to a song in this stage of the mastering process. Bass can be increased or decreased while the highs I in the song may be increased or decreased as well. The mastering engineer will attempt to isolate and alter different frequencies within the track so that some frequencies will be improved while others left unchanged.
Compression consists of various actions taken by the mastering engineer in effort to maximize the volume of the overall track while avoiding distortion or any other losses in the quality of the track. Compression may be used to assist EQ by adding punch, clarity, and bass. Like EQ, the mastering engineer may also use compression in an attempt to isolate and alter different frequencies within the track so that some frequencies will be improved.
Song spacing refers to the amount of space that lies in between each song on the disc. This can be done by a computer but most mastering engineers prefer to do this manually or by the ear for a more natural flow.
There are many other techniques that a mastering engineer may use in manipulating these four main components and no two mastering engineers use the same techniques. The most important technique that all mastering engineers must use is a good set of experienced listening techniques. Listening techniques can only be learned through experience. One thing is for sure, a good mastering engineer can make your music sound great.