A copy from a master or an earlier generation.

To make a dub. Dub or overdub:

1. To replace voice or dialogue in a film or video soundtrack, usually with another language.

2. To add music, sound effect or extra content to a soundtrack or multi-track sound recording.

Dub editing, insert editing:

Selective copying from source recordings onto a new recording – the basis of all editing since the end of the razor blade era right through to the true random access era.

Copying takes time and exposes the signal to possible distortions – generation losses.

Some digital VTR formats very much reduce the distortions.

Random access or non-linear editing systems and workstations typically store audio and video files on hard disc drives, sometimes with tape backup.

Edits may be non-destructive, in which only the playout order is changed, or destructive, in which case the file is over-written.

Dubbing mixer: A sound engineer who mixes together or balances material for soundtracks.