Stem mixing and mastering

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Image of Sub-group (stem) buses on a mixing console. Sub groups.jpg
Image of Sub-group (stem) buses on a mixing console.
Image of group assign features on individual mix channels of a mixing console. Green arrows indicate group assign buttons. Group assign.jpg
Image of group assign features on individual mix channels of a mixing console. Green arrows indicate group assign buttons.

Stem-mixing is a method of mixing audio material based on creating groups of audio tracks and processing them separately prior to combining them into a final master mix. Stems are also sometimes referred to as submixes, subgroups, or buses.

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The distinction between a stem and a separation is rather unclear. Some consider stem manipulation to be the same as separation mastering, although others consider stems to be sub-mixes to be used along with separation mastering. It depends on how many separate channels of input are available for mixing and/or at which stage they are on the way towards reducing them to a final stereo mix.

The technique originated in the 1960s, with the introduction of mixing boards equipped with the capability to assign individual inputs to sub-group faders and to work with each sub-group (stem mix) independently from the others. The approach is widely used in recording studios to control, process and manipulate entire groups of instruments such as drums, strings, or backup vocals, in order to streamline and simplify the mixing process. Additionally, as each stem-bus usually has its own inserts, sends and returns, the stem-mix (sub-mix) can be routed independently through its own signal processing chain, to achieve a different effect for each group of instruments. A similar method is also utilised with digital audio workstations (DAWs), where separate groups of audio tracks may be digitally processed and manipulated through discrete chains of plugins.

Stem-mastering is a technique derived from stem mixing. Just as in stem-mixing, the individual audio tracks are grouped together, to allow for independent control and signal processing of each stem, and can be manipulated independently from each other. Most of the mastering engineers require music producers to have at least -3db headroom at each individual track before starting stem mastering process. The reason for this is to leave more space in the mix to make the mastered version sound cleaner and louder. Even though it is not commonly practiced by mastering studios, it does have its proponents.

Stem

In audio production, a stem is a group of audio sources mixed together, usually by one person, to be dealt with downstream as one unit. A single stem may be delivered in mono, stereo, or in multiple tracks for surround sound. [1]

In sound mixing for film, the preparation of stems is a common stratagem to facilitate the final mix. Dialogue, music and sound effects, called "D-M-E", are brought to the final mix as separate stems. Using stem mixing, the dialogue can easily be replaced by a foreign-language version, the effects can easily be adapted to different mono, stereo and surround systems, and the music can be changed to fit the desired emotional response. If the music and effects stems are sent to another production facility for foreign dialogue replacement, these non-dialogue stems are called "M&E". [1] [2] [3] The dialogue stem is used by itself when editing various scenes together to construct a trailer of the film; after this some music and effects are mixed in to form a cohesive sequence. [4]

In music mixing for recordings and for live sound, stems are subgroups of similar sound sources. When a large project uses more than one person mixing, stems can facilitate the job of the final mix engineer. Such stems may consist of all of the string instruments, a full orchestra, just background vocals, only the percussion instruments, a single drum set, or any other grouping that may ease the task of the final mix. Stems prepared in this fashion may be blended together later in time, as for a recording project or for consumer listening, or they may be mixed simultaneously, as in a live sound performance with multiple elements. [5] For instance, when Barbra Streisand toured in 2006 and 2007, the audio production crew used three people to run three mixing consoles: one to mix strings, one to mix brass, reeds and percussion, and one under main engineer Bruce Jackson's control out in the audience, containing Streisand's microphone inputs and stems from the other two consoles. [6]

Stems may be supplied to a musician in the recording studio so that the musician can adjust a headphones monitor mix by varying the levels of other instruments and vocals relative to the musician's own input. Stems may also be delivered to the consumer so they can listen to a piece of music with a custom blend of the separate elements.

See also

Related Research Articles

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<span class="mw-page-title-main">Mixing console</span> Device used for audio mixing

A mixing console or mixing desk is an electronic device for mixing audio signals, used in sound recording and reproduction and sound reinforcement systems. Inputs to the console include microphones, signals from electric or electronic instruments, or recorded sounds. Mixers may control analog or digital signals. The modified signals are summed to produce the combined output signals, which can then be broadcast, amplified through a sound reinforcement system or recorded.

<span class="mw-page-title-main">Recording studio</span> Facility for sound recording

A recording studio is a specialized facility for recording and mixing of instrumental or vocal musical performances, spoken words, and other sounds. They range in size from a small in-home project studio large enough to record a single singer-guitarist, to a large building with space for a full orchestra of 100 or more musicians. Ideally, both the recording and monitoring spaces are specially designed by an acoustician or audio engineer to achieve optimum acoustic properties.

<span class="mw-page-title-main">Multitrack recording</span> Separate recording of multiple sound sources to create a cohesive whole

Multitrack recording (MTR), also known as multitracking, is a method of sound recording developed in 1955 that allows for the separate recording of multiple sound sources or of sound sources recorded at different times to create a cohesive whole. Multitracking became possible in the mid-1950s when the idea of simultaneously recording different audio channels to separate discrete "tracks" on the same reel-to-reel tape was developed. A "track" was simply a different channel recorded to its own discrete area on the tape whereby their relative sequence of recorded events would be preserved, and playback would be simultaneous or synchronized.

<span class="mw-page-title-main">Dynamic range compression</span> Audio signal processing operation

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 commonly used in sound recording and reproduction, broadcasting, live sound reinforcement and in some instrument amplifiers.

A sound editor is a creative professional responsible for selecting and assembling sound recordings in preparation for the final sound mixing or mastering of a television program, motion picture, video game, or any production involving recorded or synthetic sound. The sound editor works with the supervising sound editor. The supervising sound editor often assigns scenes and reels the sound editor based on the editor's strengths and area of expertise. Sound editing developed out of the need to fix the incomplete, undramatic, or technically inferior sound recordings of early talkies, and over the decades has become a respected filmmaking craft, with sound editors implementing the aesthetic goals of motion picture sound design.

<span class="mw-page-title-main">Monaural</span> Sound intended to be heard as if it were emanating from one position

Monaural or monophonic sound reproduction is sound intended to be heard as if it were emanating from one position. This contrasts with stereophonic sound or stereo, which uses two separate audio channels to reproduce sound from two microphones on the right and left side, which is reproduced with two separate loudspeakers to give a sense of the direction of sound sources. In mono, only one loudspeaker is necessary, but, when played through multiple loudspeakers or headphones, identical signals are fed to each speaker, resulting in the perception of one-channel sound "imaging" in one sonic space between the speakers. Monaural recordings, like stereo ones, typically use multiple microphones fed into multiple channels on a recording console, but each channel is "panned" to the center. In the final stage, the various center-panned signal paths are usually mixed down to two identical tracks, which, because they are identical, are perceived upon playback as representing a single unified signal at a single place in the soundstage. In some cases, multitrack sources are mixed to a one-track tape, thus becoming one signal. In the mastering stage, particularly in the days of mono records, the one- or two-track mono master tape was then transferred to a one-track lathe used to produce a master disc intended to be used in the pressing of a monophonic record. Today, however, monaural recordings are usually mastered to be played on stereo and multi-track formats, yet retain their center-panned mono soundstage characteristics.

<span class="mw-page-title-main">Pro Tools</span> Digital audio workstation

Pro Tools is a digital audio workstation (DAW) developed and released by Avid Technology for Microsoft Windows and macOS. It is used for music creation and production, sound for picture and, more generally, sound recording, editing, and mastering processes.

<span class="mw-page-title-main">Digital audio workstation</span> Computer system used for editing and creating music and audio

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 integrated stand-alone unit, all the way to a highly complex configuration of numerous components controlled by a central computer. Regardless of configuration, modern DAWs have a central interface that allows the user to alter and mix multiple recordings and tracks into a final produced piece.

<span class="mw-page-title-main">Sound reinforcement system</span> Amplified sound system for public events

A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is also used to enhance or alter the sound of the sources on the stage, typically by using electronic effects, such as reverb, as opposed to simply amplifying the sources unaltered.

<span class="mw-page-title-main">Aux-send</span> Electronic signal-routing output

An aux-send is an electronic signal-routing output used on multi-channel sound mixing consoles used in recording and broadcasting settings and on PA system amplifier-mixers used in music concerts. The signal from the auxiliary send is often routed through outboard audio processing effects units and then returned to the mixer using an auxiliary return input jack, thus creating an effects loop. This allows effects to be added to an audio source or channel within the mixing console. Another common use of the aux send mix is to create monitor mixes for the onstage performers' monitor speakers or in-ear monitors. The aux send's monitor mix is usually different from the front of house mix the audience is hearing.

<span class="mw-page-title-main">DJ mixer</span> Type of audio mixing console

A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance club. Hip hop DJs and turntablists use the DJ mixer to play record players like a musical instrument and create new sounds. DJs in the disco, house music, electronic dance music and other dance-oriented genres use the mixer to make smooth transitions between different sound recordings as they are playing. The sources are typically record turntables, compact cassettes, CDJs, or DJ software on a laptop. DJ mixers allow the DJ to use headphones to preview the next song before playing it to the audience. Most low- to mid-priced DJ mixers can only accommodate two turntables or CD players, but some mixers can accommodate up to four turntables or CD players. DJs and turntablists in hip hop music and nu metal use DJ mixers to create beats, loops and so-called scratching sound effects.

<span class="mw-page-title-main">Live sound mixing</span> Blending of multiple sound sources for a live event

Live sound mixing is the blending of multiple sound sources by an audio engineer using a mixing console or software. Sounds that are mixed include those from instruments and voices which are picked up by microphones and pre-recorded material, such as songs on CD or a digital audio player. Individual sources are typically equalised to adjust the bass and treble response and routed to effect processors to ultimately be amplified and reproduced via a loudspeaker system. The live sound engineer listens and balances the various audio sources in a way that best suits the needs of the event.

<span class="mw-page-title-main">Center channel</span> Audio channel

Center channel refers to an audio channel common to many surround sound formats. It is the channel that is mostly, or fully, dedicated to the reproduction of the dialogue of an audiovisual program. The speaker(s) connected to the center channel are placed in the center of and behind the perforated projection screen, to give the effect that sounds from the center channel are coming from the screen. In many home surround sound units, the center channel is positioned above or below the video screen.

<span class="mw-page-title-main">Stage monitor system</span> Sound reinforcement for performers

A stage monitor system is a set of performer-facing loudspeakers called monitor speakers, stage monitors, floor monitors, wedges, or foldbacks on stage during live music performances in which a sound reinforcement system is used to amplify a performance for the audience. The monitor system allows musicians to hear themselves and fellow band members clearly.

<span class="mw-page-title-main">Audio engineer</span> Engineer involved in the recording, reproduction, or reinforcement of sound

An audio engineer helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, and reinforcement of sound. Audio engineers work on the "technical aspect of recording—the placing of microphones, pre-amp knobs, the setting of levels. The physical recording of any project is done by an engineer... the nuts and bolts."

<span class="mw-page-title-main">Audio mixing (recorded music)</span> Audio mixing to yield recorded sound

In sound recording and reproduction, audio mixing is the process of optimizing and combining multitrack recordings into a final mono, stereo or surround sound product. In the process of combining the separate tracks, their relative levels are adjusted and balanced and various processes such as equalization and compression are commonly applied to individual tracks, groups of tracks, and the overall mix. In stereo and surround sound mixing, the placement of the tracks within the stereo field are adjusted and balanced. Audio mixing techniques and approaches vary widely and have a significant influence on the final product.

A mixing engineer is responsible for combining ("mixing") different sonic elements of an auditory piece into a complete rendition, whether in music, film, or any other content of auditory nature. The finished piece, recorded or live, must achieve a good balance of properties, such as volume, pan positioning, and other effects, while resolving any arising frequency conflicts from various sound sources. These sound sources can comprise the different musical instruments or vocals in a band or orchestra, dialogue or foley in a film, and more.

<span class="mw-page-title-main">Matrix mixer</span> Audio device that routes multiple audio signals

A matrix mixer is an audio electronics device that routes multiple input audio signals to multiple outputs. It usually employs level controls such as potentiometers to determine how much of each input is going to each output, and it can incorporate simple on/off assignment buttons. The number of individual controls is at least the number of inputs multiplied by the number of outputs.

In audio production, a stem is a discrete or grouped collection of audio sources mixed together, usually by one person, to be dealt with downstream as one unit. A single stem may be delivered in mono, stereo, or in multiple tracks for surround sound.

References

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  2. Tozer, Edwin Paul J. (2004). Broadcast Engineer's Reference Book. Taylor & Francis. p. 615. ISBN   0240519086.
  3. LoBrutto, Vincent (1994). Sound-On-Film: Interviews With Creators of Film Sound (2 ed.). Greenwood. p. 183. ISBN   0275944433.
  4. Woodhall, Woody (2010). Audio Production and Postproduction. Jones & Bartlett. pp. 461–462. ISBN   978-1449603205.
  5. Bennett, Stephen (October 2005). "Stem Mixing In Logic". Sound on Sound.
  6. "Studio Legend Bruce Jackson Chooses VENUE and Pro Tools for Streisand World Tour". Digidesign press release. CreativeCow.net. 6 February 2007. Retrieved 8 February 2011.

Further reading