The first objective is to solve any problem, improve and make the album homogeneous through the specific use of compressors and equalizers, as well as through the optimization of the volumes of the individual tracks in relation to others, to obtain a consistent sound enters each one of the songs that compose it.
During the mastering phase, the Mastering Engineer fullfils a series of processes that allow you to model each song and balance the content of the album, so that it expresses all its sound potential.
Mastering is usually done in the stereo mix of the different tracks, or in the stems (sub-mix). But what is the difference between stereo mix and stems?
Mastering a series of songs that have been mixed in stereo, in reality, offers fewer possibilities for intervention to the mastering technician, who can intervene, in fact, exclusively in the set of elements of the mix poured in a single stereo file. The advantages of this approach relate mainly to an easy management of a single stereo file.
The typical interventions during the mastering phase (stereo and stems) mainly refer to:
In addition to these more classic types of interventions, the mastering technician can also evaluate the use of exciter, reverberations, multiband compressors and much more.
Doing Stem Mastering means that you no longer have to master a single bone in a series of more stereo files given by the logical set of several musical instruments, which sum determines the final mix of the song.
For example, the mastering technician, in this way could have a stereo file that includes all the guitars, a file that includes all the keyboards, another file that includes the metal, another file of strings and then the choirs, box, chest, and all other rhythmic elements, etc. in which to intervene.
The total of these groups of instruments, which can be managed separately and with a greater level of detail than a single stereo file, offers numerous advantages for the mastering technician, who can solve phase problems by intervening exclusively in the group of instruments involved, can deal with the main voice in the best way, etc.: in short, doing stem mastering means intervening exclusively in case there is a real need and to have more control over the whole master.
The Stem Mastering also has disadvantages: being able to perform more (and better) interventions implies more time, therefore, more costs for the client.