What is Mastering?

Mastering assures the compliance of the final CD to the relevant standard (for an audio CD this would be the Red Book aka IEC 60908), and shapes and enhances the audio through the application of various processes. The Mastering Engineer also lends a fresh pair of (sensitive) ears to the project

The Process of Mastering

Mastering unites a number of tracks -whether digital or analog in origin- into a complete Album. The source tracks (or “Songs”) are loaded into a Digital Audio Workstation, checked for errors (such as dropouts, false starts) and arranged in the desired order.

After assessing the audio, the Mastering Engineer makes any necessary artistic changes to the audio; by applying equalization to correct the frequency response, and compression to shape the dynamics of the audio. Other processes possibly used are for the manipulations of the Stereo image, as well as removal of Noises.

Track gaps and track volumes are adjusted in order to establish the flow of the Album. Before writing the final master, the sub-codes that indicate starts and pauses, ISRC Codes, EAN Codes and CD-Text, are inserted. This is often referred to as PQ coding The master CD is then written and tested for audio and optical errors.

CD Text vs. Gracenote

CD-Text is an extension to the Red Book Standard. Information about the album and the tracks are encoded in the sub-codes. This includes track name, artiste, composer and genre. Only some CD Players and computer media players can read CD-Text – Windows Media player and iTunes cannot.

Gracenote is a database that maintains records of the PQ coding of a vast number of Albums. Since virtually no Albums are alike in respect of track length and pauses, software used to rip or play CDs can interrogate the database for information about the Album being played.

PMCD

PMCD or Pre-Master CD was a format for master delivery developed by Sony and Sonic Solutions in the early 90's. A PMCD contained the audio as well as a hidden file containing meta-data detailing the PQ coding. Although the PMCD format is obsolete, the term is still sometimes used synonymously with Master CD.