Mastering is the final stage of the audio production process, after the recorded audio files have been assembled into the final mix. Mastering is a vital step between production and commercial release and consumption, processing the final mix in order to prepare a track for its master form, which will be the source of all commercial copies produced.
The Mastering process prepares the final mix for commercial release and stroes the 'master' on some form of data storage device, which will hold the audio master of a track and be the source of which all commercial copies are made for release.
The process itself requires critical listening and trained ears, as well as hardware and software tools to help facilitate the process. Results will depend on the accuracy of the monitoring environment for the mastering engineer, with correct speaker alignment and acoustic treatment of the listening space being very important factors. Essentially, a near-perfect listening environment is needed to correctly critique and modify the final mix.
Additional processing is nearly always performed during mastering as the engineers may need to apply corrective equalization (EQ) and dynamic compression to enhance the audio translation on all types of playback systems. Other types of processing units have been developed to further optimize the sonic qualities of the audio during this stage.
Digital masters and mastering became widespread as recording processes evolved into digital workflows, but many mastering engineers will still incorporate analog processing in their practice – as is necessary for transferring audio to the now revitalized tape and vinyl formats.