Editing Mastering (audio) (section)

===Pre-1940s===
In the earliest days of the recording industry, all phases of the recording and mastering were entirely mechanical processes. Performers sang or played into a large [[acoustic horn]] and the master recording was created by the transfer of acoustic energy from the [[Diaphragm (acoustics)|diaphragm]] of the recording horn to the [[mastering lathe]], typically located in an adjoining room. The cutting head, driven by the energy from the horn, inscribed a modulated groove into the surface of a rotating cylinder or disc.<ref name=Auld>{{cite magazine |url=http://www.recordingmag.com/resources/resourceDetail/109.html |title=Mastering Then and Now |author=Robert Auld |magazine=Recording |access-date=2016-01-19 |archive-url=https://web.archive.org/web/20171124115019/http://www.recordingmag.com/resources/resourceDetail/109.html |archive-date=2017-11-24 |url-status=dead }}</ref> These masters were usually made from either a soft metal alloy or from [[wax]]; this gave rise to the colloquial term ''waxing'', referring to the cutting of a record.<ref>{{citation |url=https://books.google.com/books?id=k_UDAAAAMBAJ&pg=PA47 |title=New Technique Aids LP Waxing |magazine=[[Billboard (magazine)|Billboard]] |date=1950-03-25}}</ref>

After the introduction of the [[microphone]] and [[electronic amplifier]] in the mid-1920s, the mastering process became electro-mechanical, and electrically driven mastering lathes came into use for cutting master discs (the cylinder format by then having been superseded). Until the introduction of tape recording, master recordings were almost always cut [[Direct to disc recording|direct-to-disc]].<ref name=Auld/> Only a small minority of recordings were mastered using previously recorded material sourced from other discs.