The process of mastering (or more precisely premastering), is the last creative step in the recording process and the first step in CD or album replication (manufacturing). Music mastering is an art and a science and there are NO shortcuts for years of ear training and NO software application which can substitute for years of experience. For illustration, compare CD mastering to the editors job of taking a raw manuscript and turning it into a book. The book editor must understand syntax, grammar, organization and writing style, as well as know the arcane techniques of binding, color separation, printing presses and the like. Likewise, the CD mastering engineer marries the art of music with the science of sound.
As an artist, producer, engineer or independent label you may ask yourself, Why do I need to master? Of course this is a valid question, particularly when you are on a tight budget and premastering represents spending more money! There are several reasons for mastering:
To perfect the spacings and level changes between songs on your release.
To perfect the overall tonal balance of each song which may not have been achieved in mixing.
To perfect the dynamics of each song so that the record is at its optimum level.
To gain consistency between songs on the release so that transitions between songs sound natural.
To gain that competitive, world-class sound worthy of comparison to any major label release.
To acquire a low-BLER master disc, suitable for mass replication, that retains every nuance of your original performance and is truly ready to be accepted by a manufacturing plant.
In fact, many producers often have no idea in what order to arrange the tracks until after all mixes are completed. Track mixdown can take anywhere from 4 hours to 4 weeks, depending on the producers predilections, the artists whims and the budget. Normally each tune is mixed in isolation and rarely does one have the luxury to switch and compare the songs as mixing proceeds. Some mixes may be done at 2 am, when ears are fatigued or at 12 noon when ears are fresh. These things can even happen after weeks in the studio, and the problems sometimes dont become apparent until the album is assembled in its intended order.
Tending to all these factors will result in a release that is far superior in sound quality to one that has been poorly mastered or not mastered at all. Mastering requires an accurate listening environment, specific outboard gear and a mastering engineer with years of experience to do a good job. After all, you are relying upon this person to make final judgments about the sound of your music.
Read More: Mastering Process