A recording studio is a facility for sound recording and mixing. Ideally both the recording and monitoring spaces are specially designed by an acoustician to achieve optimum acoustic properties (acoustic isolation or diffusion or absorption of reflected sound that could otherwise interfere with the sound heard by the listener).
Recording studios may be used to record musicians, voice-over artists for advertisements or dialogue replacement in film, television or animation, foley, or to record their accompanying musical soundtracks. The typical recording studio consists of a room called the "studio" or "live room", where instrumentalists and vocalists perform; and the "control room", where sound engineers sometimes with producer(s) as well operate either professional audio mixing consoles or computers (post 1980s) with specialized software suites to manipulate and route the sound for analogue or digital recording. Often, there will be smaller rooms called "isolation booths" present to accommodate loud instruments such as drums or electric guitar, to keep these sounds from being audible to the microphones that are capturing the sounds from other instruments, or to provide "drier" rooms for recording vocals or quieter acoustic instruments.
Design and equipment
Recording studios generally consist of three rooms: the studio itself, where the sound for the recording is created (often referred to as the "live room"), the control room, where the sound from the studio is recorded and manipulated, and the machine room, where noisier equipment that may interfere with the recording process is kept. Recording studios are carefully designed around the principles of room acoustics to create a set of spaces with the acoustical properties required for recording sound with precision and accuracy. This will consist of both room treatment (through the use of absorption and diffusion materials on the surfaces of the room, and also consideration of the physical dimensions of the room itself in order to make the room respond to sound in a desired way) and soundproofing (also to provide sonic isolation between the rooms) to prevent sound from leaving the property. A recording studio may include additional rooms, such as a vocal booth — a small room designed for voice recording, as well as one or more extra control rooms.
Equipment found in a recording studio commonly includes:
- Mixing console
- Multitrack recorder
- Reference monitors, which are loudspeakers with a flat frequency response
- Acoustic drum kit
Equipment may include:
- Digital audio workstation
- Music workstation
- On Air or Recording Light
- Outboard effects, such as compressors, reverbs, or equalizers
Digital audio workstations
General purpose computers have rapidly assumed a large role in the recording process, being able to replace the mixing consoles, recorders, synthesizers, Samplers and sound effects devices. A computer thus outfitted is called a Digital Audio Workstation, or DAW. Popular audio-recording software includes Apple Logic Pro, Digidesign's Pro Tools—near standard for most professional studios—Cubase and Nuendo both by Steinberg, MOTU Digital Performer—popular for MIDI. Other software applications include Ableton Live, Cakewalk Sonar, ACID Pro, FL Studio, Adobe Audition, Auto-Tune, Audacity, and Ardour.
Current software applications are more reliant on the audio recording hardware than the computer they are running on, therefore typical high-end computer hardware is less of a priority unless midi is involved. While Apple Macintosh is used for most studio work, there is a breadth of software available for Microsoft Windows and Linux.
If no mixing console is used and all mixing is done using only a keyboard and mouse, this is referred to as mixing in the box ("ITB"). "OTB" is used when mixing with other hardware and not just the PC software.
A small, personal recording studio is sometimes called a project studio or home studio. Such studios often cater to specific needs of an individual artist, or are used as a non-commercial hobby. The first modern project studios came into being during the mid-1980s, with the advent of affordable multitrack recording devices, synthesizers and microphones. The phenomenon has flourished with falling prices of MIDI equipment and accessories, as well as inexpensive direct to disk recording products.
Recording drums and electric guitar in a home studio is challenging, because they are usually the loudest instruments. Conventional drums require sound isolation in this scenario, unlike electronic or sampled drums. Getting an authentic electric guitar amp sound including power-tube distortion requires a power attenuator (either power-soak or power-supply based) or an isolation box or booth. A convenient compromise is amp simulation, whether a modelling amp, preamp/processor, or software-based guitar amp simulator. Sometimes, musicians replace loud, inconvenient instruments such as drums, with keyboards, which today often provide somewhat realistic sampling.
The capability of digital recording introduced by the Alesis ADAT and its comparatively low cost, originally introduced at $3995, were largely responsible for the rise of project studios in the 1990s.
An isolation booth is a standard small room in a recording studio, which is both soundproofed to keep out external sounds and keep in the internal sounds and, like all the other recording rooms in sound industry, it is designed for having a lesser amount of diffused reflections from walls to make a good sounding room. A drummer, vocalist, or guitar speaker cabinet, along with microphones, is acoustically isolated in the room. A professional recording studio has a control room, a large live room, and one or more small isolation booths. All rooms are soundproofed such as with double-layer walls with dead space and insulation in-between the two walls, forming a room-within-a-room.
Thomas A. Watson invented, but didn't patent, the soundproof booth for use in demonstrating the telephone with Alexander Graham Bell in 1877.  There are variations of the same concept, including a portable standalone isolation booth, a compact guitar speaker isolation cabinet, or a larger guitar speaker cabinet isolation box.
A gobo panel achieves the same idea to a much more moderate extent; for example, a drum kit that is too loud in the live room or on stage can have acrylic glass see-through gobo panels placed around it to deflect the sound and keep it from bleeding into the other microphones, allowing more independent control of each instrument channel at the mixing board.
All rooms in a recording studio may have a reconfigurable combination of reflective and non-reflective surfaces, to control the amount of reverberation.
In animation, vocal performances are normally recorded in individual sessions, and the actors have to imagine (with the help of the director and/or a reader) they are involved in dialogue (as opposed to a monologue). Animated films often evolve rapidly during both development and production, so keeping vocal tracks from bleeding into each other is essential to preserving the ability to fine-tune lines up to the last minute. Sometimes, if the rapport between the lead actors is strong enough and the animation studio can afford it, the producers may use a recording studio configured with multiple isolation booths in which the actors can see each another and the director. This enables the actors to react to one another in real time as if they were on a regular stage or film set.
1890s to 1930s
In the era of acoustical recordings (prior to the introduction of microphones, electrical recording and amplification), the earliest recording studios were very basic facilities, being essentially soundproof rooms that isolated the performers from outside noise. During this era it was not uncommon for recordings to be made in any available location, such as a local ballroom, using portable acoustic recording equipment.
In this period, master recordings were made using a direct-to-disc cutting process. Performers were typically grouped around a large acoustic horn (an enlarged version of the familiar phonograph horn). The acoustic energy from the voices and/or instruments was channeled through the horn's diaphragm to a mechanical cutting lathe located in the next room, which inscribed the signal as a modulated groove directly onto the surface of the master cylinder or disc.
Following the invention and commercial introduction of the microphone, the electronic amplifier, the mixing desk and the loudspeaker, the recording industry gradually converted to electric recording, and by 1925 this technology had replaced mechanical acoustic recording methods for such major labels as RCA Victor and Columbia, and by 1933 acoustic recording was completely disused.
1940s to 1970s
Electrical recording was common by the early 1930s, and mastering lathes were now electrically powered, but master recordings still had to be cut direct-to-disc. In line with the prevailing musical trends, studios in this period were primarily designed for the live recording of symphony orchestras and other large instrumental ensembles. Engineers soon found that large, reverberant spaces like concert halls created a vibrant acoustic signature that greatly enhanced the sound of the recording, and in this period large, acoustically "live" halls were favored, rather than the acoustically "dead" booths and studio rooms that became common after the 1960s.
Because of the limits of the recording technology, studios of the mid-20th century were designed around the concept of grouping musicians and singers, rather than separating them, and placing the performers and the microphones strategically to capture the complex acoustic and harmonic interplay that emerged during the performance. Modern sound stages still sometimes use this approach for large film scoring projects today.
Because of their superb acoustics, many of the larger studios were converted churches. Examples include George Martin's AIR Studios in London, the famed Columbia Records 30th Street Studio in New York City (a converted Armenian church, with a ceiling over 100 feet high), and the equally famous Decca Records Pythian Temple studio in New York (where artists like Louis Jordan, Bill Haley and Buddy Holly were recorded) which was also a large converted church that featured a high, domed ceiling in the center of the hall.
Facilities like the Columbia Records 30th Street Studio in New York and EMI's Abbey Road Studio in London were renowned for their 'trademark' sound—which was (and still is) easily identifiable by audio professionals—and for the skill of their staff engineers.
In New York City, Columbia Records had some of the most highly respected sound recording studios, including the Columbia 30th Street Studio at 207 East 30th Street, the CBS Studio Building at 49 East 52nd Street, Liederkranz Hall at 111 East 58th Street between Park and Lexington Avenues (a building built by and formerly belonging to a German cultural and musical society, The Liederkranz Club and Society), and one of their earliest recording studios, "Studio A" at 799 Seventh Avenue.
Electric recording studios in the mid-20th century often lacked isolation booths, baffles, and sometimes even speakers, and it was not until the 1960s, with the introduction of the high-fidelity headphones that it became common practice for performers to use headsets to monitor their performance during recording and listen to playbacks.
It was difficult to isolate all the performers—a major reason that this practice was not used was simply because recordings were usually made as live ensemble 'takes' and all the performers needed to be able to see each other and the ensemble leader while playing. The recording engineers who trained in this period learned to take advantage of the complex acoustic effects that could be created through "leakage" between different microphones and groups of instruments, and these technicians became extremely skilled at capturing the unique acoustic properties of their studios and the musicians in performance.
The use of different kinds of microphones and their placement around the studio was a crucial part of the recording process, and particular brands of microphone were used by engineers for their specific audio characteristics. The smooth-toned ribbon microphones developed by the RCA company in the 1930s were crucial to the 'crooning' style perfected by Bing Crosby, and the famous Neumann U47 condenser microphone was one of the most widely used from the 1950s. This model is still widely regarded by audio professionals as one of the best microphones of its type ever made.
Learning the correct placement of microphones was a major part of the training of young engineers, and many became extremely skilled in this craft. Well into the 1960s, in the classical field it was not uncommon for engineers to make high-quality orchestral recordings using only one or two microphones suspended above the orchestra.
In the 1960s, engineers began experimenting with placing microphones much closer to instruments than had previously been the norm. The distinctive rasping tone of the horn sections on the Beatles recordings "Good Morning Good Morning" and "Lady Madonna" were achieved by having the saxophone players position their instruments so that microphones were virtually inside the mouth of the horn.
The unique sonic characteristics of the major studios imparted a special character to many of the most famous popular recordings of the 1950s and 1960s, and the recording companies jealously guarded these facilities. According to sound historian David Simons, after Columbia took over the 30th Street Studios in the late 1940s and A&R manager Mitch Miller had tweaked it to perfection, Miller issued a standing order that the drapes and other fittings were not to be touched, and the cleaners had specific orders never to mop the bare wooden floor for fear it might alter the acoustic properties of the hall.
There were several other features of studios in this period that contributed to their unique "sonic signatures". As well as the inherent sound of the large recording rooms, many of the best studios incorporated specially-designed echo chambers, purpose-built rooms which were often built beneath the main studio.
These were typically long, low rectangular spaces constructed from hard, sound-reflective materials like concrete, fitted with a loudspeaker at one end and one or more microphones at the other. During a recording session, a signal from one or more of the microphones in the studio could be routed to the loudspeaker in the echo chamber; the sound from the speaker reverberated through the chamber and the enhanced signal was picked up by the microphone at the other end. This echo-enhanced signal—which was often used to 'sweeten' the sound of vocals—could then be blended in with the primary signal from the microphone in the studio and mixed into the track as the master recording was being made.
Special equipment was another notable feature of the "classic" recording studio. The biggest studios were owned and operated by large media companies like RCA, Columbia and EMI, who typically had their own electronics research and development divisions that designed and built custom-made recording equipment and mixing consoles for their studios.
Likewise, the smaller independent studios were often owned by skilled electronics engineers who designed and built their own desks and other equipment. A good example of this is the famous Gold Star Studios in Los Angeles, the site of many famous American pop recordings of the 1960s. Co-owner David S. Gold built the studio's main mixing desk and many additional pieces of equipment and he also designed the studio's unique trapezoidal echo chambers.
During the 1950s and 1960s, the sound of pop recordings was further defined by the introduction of proprietary sound processing devices such as equalizers and compressors, which were manufactured by specialist electronics companies. One of the best known of these was the famous Pultec equalizer, which was used by almost all the major commercial studios of the time.
With the introduction of multi-track recording, it became possible to record instruments and singers separately and at different times on different tracks on tape, although it was not until the 1970s that the large recording companies began to adopt this practice widely, and throughout the 1960s many "pop" classics were still recorded live in a single take.
After the 1960s, the emphasis shifted to isolation and sound-proofing, with treatments like echo and reverberation added separately during the mixing process, rather than being blended in during the recording. One regrettable outcome of this trend, which coincided with rising inner-city property values, was that many of the largest studios were either demolished or redeveloped for other uses.
In the mid 20th century, recordings were analog, made on ¼-inch or ½-inch magnetic tape, with multitrack recording reaching 8 tracks in the 1950s, 16 in 1968, and 32 in the 1970s. The commonest such tape is the 2-inch analog, capable of containing up to 24 individual tracks. Generally, after an audio mix is set up on a 24-track tape machine, the signal is played back and sent to a different machine, which records the combined signals (called printing) to a ½-inch 2-track stereo tape, called a master.
Before digital recording, the total number of available tracks onto which one could record was measured in multiples of 24, based on the number of 24-track tape machines being used. Most recording studios now use digital recording equipment, which limits the number of available tracks only on the basis of the mixing console's or computer hardware interface's capacity and the ability of the hardware to cope with processing demands.
Analog tape machines are still well sought, for some purists label digitally recorded audio as sounding too harsh, and the scarcity and age of analog tape machines greatly increases their value, as does the fact that many audio engineers still insist on recording only to analog tape.
Radio studios are very similar to recording studios, particularly in the case of production studios which are not normally used on-air. This type of studio would normally have all of the same equipment that any other audio recording studio would have, particularly if it is at a large station, or at a combined facility that houses a station group, but is designed for groups of people to work collaboratively in a live to air situation (see Ahern, S, Making Radio).
Broadcast studios also use many of the same principles such as sound isolation, with adaptations suited to the live on-air nature of their use. Such equipment would commonly include a telephone hybrid for putting telephone calls on the air, a POTS codec for receiving remote broadcasts, a dead air alarm for detecting unexpected silence, and a broadcast delay for dropping anything from coughs to profanity. In the U.S., stations licensed by the Federal Communications Commission (FCC) also must have an Emergency Alert System decoder (typically in the studio), and in the case of full-power stations, an encoder that can interrupt programming on all channels which a station transmits in order to broadcast urgent warnings.
Computers are also used for playing ads, jingles, bumpers, soundbites, phone calls, sound effects, traffic and weather reports, and now full broadcast automation when nobody is around. For talk shows, a producer and/or assistant in a control room runs the show, including screening calls and entering the callers' names and subject into a queue, which the show's host can see and make a proper introduction with. Radio contest winners can also be edited on the fly and put on the air within a minute or two after they have been recorded accepting their prize.
Additionally, digital mixing consoles can be interconnected via audio over Ethernet, or split into two parts, with inputs and outputs wired to a rackmount audio engine, and one or more control surfaces (mixing boards) and/or computers connected via serial port, allowing the producer or the talent to control the show from either point. With Ethernet and audio over IP (live) or FTP (recorded), this also allows remote access, so that DJs can do shows from a home studio via ISDN or the Internet. Additional outside audio connections are required for the studio/transmitter link for over-the-air stations, satellite dishes for sending and receiving shows, and for webcasting or podcasting.
- Audio engineering
- Isolation cabinet (guitar)
- Record producer
- Room acoustics
- Sound recording
- Sound baffle
- Talkback (recording)
- List of music software
- George Petersen, "In Memoriam: Keith Barr 1949-2010", Mix Magazine Online, Aug 2010, http://mixonline.com/news/keith_barr_obit_2508/index1.html
- The birth and babyhood of the telephone
- Simons, David (2004). Studio Stories - How the Great New York Records Were Made. San Francisco: Backbeat Books.
- "History of The Liederkranz of the City of New York" - The Liederkranz of the City of New York website. The Liederkranz Club put up a building in 1881 at 111-119 East 58th Street, east of Park Avenue.
- Kahn, Ashley, Kind of Blue: The Making of the Miles Davis Masterpiece, Da Capo Press, 2001. Cf. p.75
- Ahern, S (ed), Making Radio, Allen & Unwin, Sydney, 2011. Studio Chapter
- Cogan, Jim; Clark, William,Temples of Sound: Inside the Great Recording Studios.] San Francisco, CA: Chronicle Books, 2003.
- Horning, Susan Schmidt, Chasing Sound: Technology, Culture, and the Art of Studio Recording from Edison to the LP. Baltimore, MD: Johns Hopkins University Press, 2013.
- Ramone, Phil and Granata, Charles L., Making Records: The Scenes Behind the Music. New York: Hyperion, 2007.