![Reel-to-ReelTapeBigHub](https://upload.wikimedia.org/wikipedia/commons/6/66/Reel-to-ReelTapeBigHub.agr.jpg)
Mastering, a form of
audio post production
Audio post production is all stages of audio production relating to sound produced and synchronized with moving picture (film, television, or video). It involves sound design, sound effects, Foley, ADR, sound editing, audio mixing, mastering et ...
, is the process of preparing and transferring recorded audio from a source containing the
final mix to a
data storage device
Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are conside ...
(the master), the source from which all copies will be produced (via methods such as pressing, duplication or
replication). In recent years
digital master {{For, the Sony product line called DigitalMaster, DVCAM
A digital master is an image, PDF file, digital recording or another digital asset preserved as the "original" for the purpose of archival storage, reuse and re-expression. For images, it is ...
s have become usual, although analog masters—such as audio tapes—are still being used by the manufacturing industry, particularly by a few engineers who specialize in analog mastering.
Mastering requires critical listening; however, software tools exist to facilitate the process. Results depend upon the intent of the engineer, the skills of the engineer, the accuracy of the speaker monitors, and the listening environment.
Mastering engineer
A mastering engineer is a person skilled in the practice of taking audio (typically musical content) that has been previously mixed in either the analog or digital domain as mono, stereo, or multichannel formats and preparing it for use in distr ...
s often apply
equalization and
dynamic range compression
Dynamic range compression (DRC) or simply compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, thus reducing or ''compressing'' an audio signal's dynamic range. Compression is ...
in order to optimize sound translation on all playback systems.
It is standard practice to make a copy of a master recording—known as a safety copy—in case the master is lost, damaged or stolen.
History
Pre-1940s
In the earliest days of the recording industry, all phases of the recording and mastering process were entirely achieved by mechanical processes. Performers sang and/or played into a large acoustic horn and the master recording was created by the direct transfer of acoustic energy from the
diaphragm
Diaphragm may refer to:
Anatomy
* Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen
* Pelvic diaphragm or pelvic floor, a pelvic structure
* Urogenital diaphragm or triangular ligament, a pelvic structure
Other
* Diap ...
of the recording horn to the
mastering lathe
upPresto 8N Disc Cutting Lathe (1950) used by the Canadian Broadcasting Corporation to record radio programs
A disc cutting lathe is a device used to transfer an audio signal to the modulated spiral groove of a blank master disc for the productio ...
, typically located in an adjoining room. The cutting head, driven by the energy transferred from the horn, inscribed a modulated groove into the surface of a rotating cylinder or disc.
These masters were usually made from either a soft metal alloy or from
wax
Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low ...
; this gave rise to the colloquial term ''waxing'', referring to the cutting of a record.
After the introduction of the
microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...
and
electronic amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a Signal (information theory), signal (a time-varying voltage or Electric current, current). It may increase the power (physics ...
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.
[ Only a small minority of recordings were mastered using previously recorded material sourced from other discs.
]
Emergence of magnetic tape
In the late 1940s, the recording industry was revolutionized by the introduction of magnetic tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magne ...
. Magnetic tape was invented for recording sound by Fritz Pfleumer
Fritz Pfleumer (20 March 1881 – 29 August 1945) was a German engineer who invented magnetic tape for recording sound.
Biography
Fritz was born as the son of Robert and Minna, née Hünich. His father Robert (1848–1934) was born in Greiz, ...
in 1928 in Germany, based on the invention of magnetic wire recording
Wire recording or magnetic wire recording was the first magnetic recording technology, an analog type of audio storage in which a magnetic recording is made on a thin steel wire. The first crude magnetic recorder was invented in 1898 by Valdem ...
by Valdemar Poulsen
Valdemar Poulsen (23 November 1869 – 23 July 1942) was a Danish engineer who made significant contributions to early radio technology. He developed a magnetic wire recorder called the telegraphone in 1898 and the first continuous wave radio ...
in 1898. Not until the end of World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
could the technology be found outside Europe. The introduction of magnetic tape recording enabled master discs to be cut separately in time and space from the actual recording process.[
Although tape and other technical advances dramatically improved the audio quality of commercial recordings in the post-war years, the basic constraints of the electro-mechanical mastering process remained, and the inherent physical limitations of the main commercial recording media—the 78 rpm disc and later the 7-inch 45 rpm single and 33-1/3 rpm ]LP record
The LP (from "long playing" or "long play") is an analog sound storage medium, a phonograph record format characterized by: a speed of rpm; a 12- or 10-inch (30- or 25-cm) diameter; use of the "microgroove" groove specification; and a ...
—meant that the audio quality, dynamic range
Dynamic range (abbreviated DR, DNR, or DYR) is the ratio between the largest and smallest values that a certain quantity can assume. It is often used in the context of signals, like sound and light. It is measured either as a ratio or as a base-1 ...
, and running time of master discs were still limited compared to later media such as the compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...
.
Electro-mechanical mastering process
From the 1950s until the advent of digital recording in the late 1970s, the mastering process typically went through several stages. Once the studio recording on multi-track tape was complete, a final mix
Mix, mixes or mixing may refer to:
Persons & places
* Mix (surname)
** Tom Mix (1880-1940), American film star
* nickname of Mix Diskerud (born Mikkel, 1990), Norwegian-American soccer player
* Mix camp, an informal settlement in Namibia
* Mix ...
was prepared and dubbed down to the master tape, usually either a single-track mono
Mono may refer to:
Common meanings
* Infectious mononucleosis, "the kissing disease"
* Monaural, monophonic sound reproduction, often shortened to mono
* Mono-, a numerical prefix representing anything single
Music Performers
* Mono (Japanese b ...
or two-track stereo
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration ...
tape. Prior to the cutting of the master disc, the master tape was often subjected to further electronic treatment by a specialist mastering engineer
A mastering engineer is a person skilled in the practice of taking audio (typically musical content) that has been previously mixed in either the analog or digital domain as mono, stereo, or multichannel formats and preparing it for use in distr ...
.
After the advent of tape it was found that, especially for pop recordings, master recordings could be made so that the resulting record would sound better. This was done by making fine adjustments to the amplitude of sound at different frequency bands ( equalization) prior to the cutting of the master disc.
In large recording companies such as EMI
EMI Group Limited (originally an initialism for Electric and Musical Industries, also referred to as EMI Records Ltd. or simply EMI) was a British transnational conglomerate founded in March 1931 in London. At the time of its break-up in 201 ...
, the mastering process was usually controlled by specialist staff technicians who were conservative in their work practices. These big companies were often reluctant to make changes to their recording and production processes. For example, EMI was very slow in taking up innovations in multi-track recording
Multi-track may refer to:
* Multitrack recording, the process of mixing individual sound sources to a single recording
* Multi-track diplomacy, a method of conflict resolution
* Multi track, a process of civil litigation in England and Wales
** Fa ...
and did not install 8-track recorders in their Abbey Road Studios
Abbey Road Studios (formerly EMI Recording Studios) is a recording studio at 3 Abbey Road, St John's Wood, City of Westminster, London, England. It was established in November 1931 by the Gramophone Company, a predecessor of British music c ...
until the late 1960s, more than a decade after the first commercial 8-track recorders were installed by American independent studios.
Digital technology
In the 1990s, electro-mechanical processes were largely superseded by digital technology, with digital recordings stored on hard disk drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
s or digital tape and mastered to CD. The digital audio workstation
A digital audio workstation (DAW) is an electronic device or application software used for Sound recording and reproduction, recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software pro ...
(DAW) became common in many mastering facilities, allowing the off-line manipulation of recorded audio via a graphical user interface
The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...
(GUI). Although many digital processing tools are common during mastering, it is also very common to use analog media and processing equipment for the mastering stage. Just as in other areas of audio, the benefits and drawbacks of digital technology compared to analog technology are still a matter for debate. However, in the field of audio mastering, the debate is usually over the use of digital versus analog signal processing rather than the use of digital technology for storage of audio.
Digital systems have higher performance and allow mixing to be performed at lower maximum levels. When mixing to 24-bits with peaks between -3 and -10 dBFS on a mix, the mastering engineer has enough headroom to process and produce a final master.[Bob Katz Mixing Tips](_blank)
Mastering engineers recommend leaving enough headroom on the mix to avoid distortion. Reduction of dynamics by the mix or mastering engineer has resulted in a loudness war
The loudness war (or loudness race) is a trend of increasing audio levels in recorded music, which reduces audio fidelity and—according to many critics—listener enjoyment. Increasing loudness was first reported as early as the 1940s, with ...
in commercial recordings.
Process
The source material, ideally at the original resolution
Resolution(s) may refer to:
Common meanings
* Resolution (debate), the statement which is debated in policy debate
* Resolution (law), a written motion adopted by a deliberative body
* New Year's resolution, a commitment that an individual mak ...
, is processed using equalization, compression
Compression may refer to:
Physical science
*Compression (physics), size reduction due to forces
*Compression member, a structural element such as a column
*Compressibility, susceptibility to compression
*Gas compression
*Compression ratio, of a c ...
, limiting
In electronics, a limiter is a circuit that allows signals below a specified input power or level to pass unaffected while attenuating (lowering) the peaks of stronger signals that exceed this threshold. Limiting is a type of dynamic range compr ...
and other processes. Additional operations, such as editing
Editing is the process of selecting and preparing written, photographic, visual, audible, or cinematic material used by a person or an entity to convey a message or information. The editing process can involve correction, condensation, orga ...
, specifying the gaps between tracks, adjusting level, fading in and out, noise reduction
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an und ...
and other signal restoration and enhancement processes can also be applied as part of the mastering stage. The source material is put in the proper order, commonly referred to as assembly (or 'track') sequencing. These operations prepare the music for either digital or analog, e.g. vinyl, replication.
If the material is destined for vinyl release, additional processing, such as dynamic range reduction or frequency-dependent stereo–to–mono fold-down and equalization may be applied to compensate for the limitations of that medium. For compact disc release, ''start of track'', ''end of track'', and ''indexes'' are defined for playback navigation along with International Standard Recording Code
The International Standard Recording Code (ISRC) is an international standard code for uniquely identifying sound recordings and music video recordings. The code was developed by the recording industry in conjunction with the ISO technical committ ...
(ISRC) and other information necessary to replicate a CD. Vinyl LP and cassettes
Cassette may refer to:
Technology
* Cassette tape (or ''musicassette'', ''audio cassette'', ''cassette tape'', or ''tape''), a worldwide standard for analog audio recording and playback
** Cassette single (or "Cassingle"), a music single in the ...
have their own pre-duplication requirements for a finished master. Subsequently, it is rendered either to a physical medium, such as a CD-R or DVD-R, or to computer files, such as a Disc Description Protocol
Disc Description Protocol (DDP) is a format for specifying the content of optical discs, including CDs and DVDs.
DDP is commonly used for delivery of disc premasters for duplication. DDP is a proprietary format
A proprietary file format is a fil ...
(DDP) file set or an ISO image
An optical disc image (or ISO image, from the ISO 9660 file system used with CD-ROM media) is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. IS ...
. Regardless of what delivery method is chosen, the replicator factory will transfer the audio to a glass master
In optical disc manufacturing, replication is the process of producing discs via methods that do not involve "burning" blank CD, DVD or other discs; the latter is known as duplication.
The replication of optical discs involves:
# the creation of ...
that will generate metal stampers for replication.
The process of audio mastering varies depending on the specific needs of the audio to be processed. Mastering engineers need to examine the types of input media, the expectations of the source producer or recipient, the limitations of the end medium and process the subject accordingly. General rules of thumb can rarely be applied.
Steps of the process typically include the following:
# Transferring the recorded audio tracks into the Digital Audio Workstation
A digital audio workstation (DAW) is an electronic device or application software used for recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integrate ...
(DAW)
# Sequence the separate songs or tracks as they will appear on the final release
# Adjust the length of the silence between songs
# Process or sweeten audio to maximize the sound quality for the intended medium (e.g. applying specific EQ for vinyl)
# Transfer the audio to the final master format (CD-ROM, half-inch reel tape, PCM 1630 U-matic tape, etc.)
Examples of possible actions taken during mastering:
# Editing minor flaws
# Applying noise reduction
Noise reduction is the process of removing noise from a signal. Noise reduction techniques exist for audio and images. Noise reduction algorithms may distort the signal to some degree. Noise rejection is the ability of a circuit to isolate an und ...
to eliminate clicks, dropouts, hum and hiss
# Adjusting stereo width
# Equalize audio across tracks for the purpose of optimized frequency distribution
# Adjust volume
# Dynamic range compression or expansion
# Peak limit
# Inserting ISRC
The International Standard Recording Code (ISRC) is an international standard code for uniquely identifying sound recordings and music video recordings. The code was developed by the recording industry in conjunction with the ISO technical committ ...
codes and CD text
# Arranging tracks in their final sequential order
# Fading out the ending of each song
# Dither
Dither is an intentionally applied form of image noise, noise used to randomize quantization error, preventing large-scale patterns such as color banding in images. Dither is routinely used in processing of both digital audio and digital vide ...
Notable audio mastering engineers
*Brad Blackwood Brad Blackwood is an American audio mastering audio engineer, engineer. He has mastered albums for artists such as Maroon 5, Against Me, Lamb of God (band), Lamb of God, Black Eyed Peas, Sara Bareilles, and is a 17 time Grammy nominee and 3-time win ...
*Greg Calbi
Gregory Calbi (born April 3, 1949) is an American mastering engineer at Sterling Sound, New Jersey.
Biography
Greg Calbi was born on April 3, 1949, in Yonkers, New York, and raised in Bayside, Queens, New York. He graduated in 1966 from Bisho ...
*Tony Dawsey Tony Dawsey is an American mastering engineer at Masterdisk in New York City. He has been active since 1980.[P. A. Deepak
P.A.Deepak (Adrushta Deepak Pallikonda) is a mix engineer and record producer. He won the 2010 Grammy Award for the " Best Compilation Soundtrack for Visual Media" for the movie ''Slumdog Millionaire''.Grammy Website. "http://www.grammy.com/no ...](_blank)
*Brian Gardner
Brian Knapp Gardner, also known as Brian "Big Bass" Gardner, is an American mastering engineer. He has worked on a number of recordings since the mid-1960s, including classic rock, funk, disco, alternative rock, R&B, hip hop, pop punk and dance- ...
*Chris Gehringer
Chris Gehringer (born May 27, 1962) is an American mastering engineer, known for having mastered recordings such as Gwen Stefani's '' Love. Angel. Music. Baby.'' (2004), Rihanna's '' Loud'' (2010), Lady Gaga's '' Born This Way'' (2011) and Drake' ...
* Kevin Gray
*Bernie Grundman
Bernie Grundman is an American audio engineer.
He is most known for his mastering work and his studio, Bernie Grundman Mastering, which he opened in 1984 in Hollywood. The studio, which includes engineers Chris Bellman, Patricia Sullivan, and Mi ...
* Steve Hoffman
*Ted Jensen
Ted Jensen (born September 19, 1954) is an American mastering engineer, known for having mastered many recordings, including the Eagles' ''Hotel California'', Green Day's '' American Idiot'' and Norah Jones' ''Come Away with Me''.
Biography
Ted ...
*Bob Katz
Bob Katz is an American audio mastering engineer and author of a popular book on audio mastering. Katz has mastered three Grammy Award–winning albums and one nominated album. Projects he has worked on have received Grammys and acclaim from audi ...
*Emily Lazar
Emily B. Lazar is an American mastering engineer. She is the founder, president, and chief mastering engineer of The Lodge, an audio mastering facility that has operated in New York City's Greenwich Village since 1997. She won a Grammy Award for ...
*Bob Ludwig
Robert C. Ludwig (born c. 1945) is an American mastering engineer. He has mastered recordings on all the major recording formats for all the major record labels, and on projects by more than 1,300 artists including Led Zeppelin, Lou Reed, Qu ...
*Stephen Marcussen
Stephen Marcussen is the founder and chief mastering engineer at Marcussen Mastering in Hollywood, California, United States. He has been mastering music since 1979.
Biography
Marcussen's introduction to music recording happened in 1976 when, at ...
*George Marino
George Marino (April 15, 1947 – June 4, 2012) was an American mastering engineer known for working on albums by rock bands starting in the late 1960s.
Biography
Marino was born on April 15, 1947, in the New York City borough The Bronx. He at ...
*Randy Merrill
Randy Merrill is an American mastering engineer who has worked with international artists including DAY6, Lady Gaga, Katy Perry, Maroon 5, Harry Styles, One Direction, Adele, Imagine Dragons, Beck, Liam Gallagher, Jonas Brothers, Muse, Cage the ...
*Mandy Parnell
Mandy Parnell is a British audio mastering engineer, founder and senior mastering engineer at Black Saloon Studios in London, England. Parnell has worked on projects with a wide variety of artists including Aphex Twin, The XX, Feist (singer), Feis ...
* George "Porky" Peckham
*Eric Pillai
Eric Pillai is an Indian sound engineer, mixing engineer and music producer. He is best known for his mix of Aashiqui 2 soundtrack for which he won GiMA Award for Best Recording Engineer.
Early life and career
Pillai aspired to become a music pr ...
* Shadab Rayeen
*Doug Sax
Doug Lionel Sax (April 26, 1936 – April 2, 2015) was an American mastering engineer from Los Angeles, California. He mastered three of The Doors' albums, including their 1967 debut; six of Pink Floyd's albums, including ''The Wall''; Ray Charles ...
*H. Sridhar
H. Sridhar (Sridhar Hariharan/H.Padmanabh) was an Indian sound engineer known for his work with the Indian musician A. R. Rahman.
Sridhar was the Chief Audio Engineer at Media Artists Chennai. A mathematics graduate, with keen interest i ...
*Ray Staff
Ray Staff is a British mastering engineer, best known for his work with a diverse mix of artists including Led Zeppelin, The Rolling Stones, The Clash and Black Sabbath. Most recently he has mastered albums for Muse.
Biography and career
Joini ...
*Rudy Van Gelder
Rudolph Van Gelder (November 2, 1924 – August 25, 2016) was an American recording engineer who specialized in jazz. Over more than half a century, he recorded several thousand sessions, with musicians including John Coltrane, Miles Davis, Theloni ...
*Howie Weinberg
Howie Weinberg is an American audio mastering engineer with over 2,257 mastering credits, three TEC Awards, 21 Grammy Awards, two Juno Awards, and one Mercury Prize.
Career
Weinberg mastered Herbie Hancock's 1983 album ''Future Shock''. Other m ...
*Leon Zervos
Leon Zervos is a mastering engineer who has worked with many world-renowned artists, including Pink, Rihanna, Maroon 5, Beastie Boys, and Willie Nelson.
Life and career
Leon Zervos began his mastering career in 1982 at the then EMI Studi ...
See also
* Album era
The album era was a period in English-language popular music from the mid-1960s to the mid-2000s in which the album was the dominant form of recorded music expression and consumption. It was primarily driven by three successive music recording ...
* Remaster
Remaster refers to changing the quality of the sound or of the image, or both, of previously created recordings, either audiophonic, cinematic, or videographic. The terms digital remastering and digitally remastered are also used.
Mastering
A ...
* 2008 Universal Studios fire
On June 1, 2008, a fire broke out on the backlot of Universal Studios Hollywood, an American film studio and theme park in the San Fernando Valley area of Los Angeles County, California. The fire began when a worker used a blowtorch to warm asph ...
Notes
References
{{DEFAULTSORT:Audio Mastering
Audio engineering
Optical disc authoring
Sound recording
Music industry