Digital remastering

Remaster (also digital remastering and digitally remastered) refers to enhancing the quality of the sound or of the image, or both, of previously created recordings, either audiophonic, cinematic, or videographic.

To understand the concept of remastering, it is beneficial to understand that often a pyramid of copies would be made from a single original "master" recording, which might itself be based on previous recordings. For example, sound effects (a door opening, punching sounds, falling down the stairs, a bell ringing, etc.) might have been added from copies of sound effect tapes similar to modern sampling to make a radio play for broadcast.

A master is the recording which experts state will be the definitive copy that is duplicated for the end user usually into other formats i.e. LP records, CDs, DVDs etc.

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 tape. This tape was mixed to create a stereo or mono master. A further master tape would likely be created from this original master recording consisting of 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 recordings 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 engineers.

With the advent of digital recording in the late 1970s, many mastering ideas changed. Previously, creating new masters meant incurring an analogue 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 noise reduction techniques exist, they also increase other audio distortions such as azimuth shift, wow and flutter, print-through and stereo image shift.

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