Editing Remaster (section)

== Mastering ==
{{Main|Mastering (audio)}}
A [[master recording]] is the definitive recording version that will be replicated for the end user, commonly into other formats (e.g. [[LP record]]s, [[Magnetic tape|tapes]], [[Compact disc|CDs]], [[DVD]]s, [[Blu-ray]]s, etc.).

A batch of copies is often made from a single original master recording, which might itself be based on previous recordings. For example, sound effects (e.g. a door opening, punching sounds, falling down the stairs, a bell ringing) might have been added from copies of sound effect tapes similar to modern sampling to make a radio play for broadcast.

Problematically, several different levels of masters often exist for any one audio release. As an example, examine the way a typical music [[album]] from the 1960s was created. Musicians and vocalists were recorded on multi-track [[Magnetic tape|tape]]. This tape was [[Audio mixing (recorded music)|mixed]] to create a [[stereo]] or [[monaural|mono]] master. A further master tape would likely be created from this original master recording consisting of [[Equalization (audio)|equalization]] and other adjustments and improvements to the audio to make it sound better on record players for example.

More master recordings would be duplicated from the equalized master for regional copying purposes (for example to send to several pressing plants). Pressing masters for [[vinyl recording]]s would be created. Often these interim recordings were referred to as ''mother tapes''. All vinyl records would derive from one of the master recordings.

Thus, ''mastering'' refers to the process of creating a master. This might be as simple as copying a tape for further duplication purposes or might include the actual equalization and processing steps used to fine-tune material for release. The latter example usually requires the work of [[mastering engineer]]s.

With the advent of [[digital recording]] in the late 1970s, many mastering ideas changed. Previously, creating new masters meant incurring an [[analog signal|analog]] generational loss; in other words, copying a tape to a tape meant reducing the [[signal-to-noise ratio]]. This means how much of the original intended "good" information is recorded against faults added to the recording as a result of the technical limitations of the equipment used (noise, e.g. [[tape hiss]], static, etc.). Although [[Audio noise reduction|noise reduction]] techniques exist, they also increase other audio distortions such as azimuth shift, [[Wow (recording)|wow]] and [[Flutter (electronics and communication)|flutter]], [[print-through]] and stereo image shift.

With digital recording, masters could be created and duplicated without incurring the usual generational loss. As [[CDs]] were a [[Digital data|digital]] format, digital masters created from original analog recordings became a necessity.