Recording studio

Recording studios generally consist of three or more rooms:

• The live room of the studio where instrumentalists play their instruments, with their playing picked up by microphones and, for electric and electronic instruments, by connecting the instruments' outputs or DI unit outputs to the mixing board (or by miking the speaker cabinets for bass and electric guitar);
• Isolation booths are small sound-insulated rooms with doors, designed for instrumentalists (or their loud speaker stacks). Vocal booths are similarly designed rooms for singers. In both types of rooms, there are typically windows so the performers can see other band members and other studio staff, as singers, bandleaders and musicians often give or receive visual cues;
• The control room, where the audio engineers and record producers mix the mic and instrument signals with a mixing console, record the singing and playing onto tape (until the 1980s and early 1990s) or hard disc (1990s and following decades) and listen to the recordings and tracks with monitor speakers or headphones and manipulate the tracks by adjusting the mixing console settings and by using effects units; and
• The machine room, where noisier equipment, such as racks of fan-cooled computers and power amplifiers, is kept to prevent the noise from interfering with the recording process.

Even though sound isolation is a key goal, the musicians, singers, audio engineers and record producers still need to be able to see each other, to see cue gestures and conducting by a bandleader. As such, the live room, isolation booths, vocal booths and control room typically have windows.

Neve VR60, a multitrack mixing console. Above the console are a range of studio monitor speakers.

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 accuracy. Architectural acoustics includes acoustical treatment and soundproofing and also the consideration of the physical dimensions of the room itself to make the room respond to sound in the desired way. Acoustical treatment includes and the use of absorption and diffusion materials on the surfaces inside the room. Soundproofing provides sonic isolation between rooms and prevents sound from entering or leaving the property. A Recording studio in an urban environment must be soundproofed on its outer shell to prevent noises from the surrounding streets and roads from being picked up by microphones inside.

Engineers and producers watch a trumpet player from a window in the control room during a recording session.

Equipment found in a recording studio commonly includes:

• A professional-grade mixing console
• Additional small mixing consoles for adding more channels (e.g., if a drum kit needs to be miked and all of the channels of the large console are in use, an additional 16 channel mixer would enable the engineers to mix the mics for the kit)
• Microphone preamplifiers
• Multitrack recorder or digital audio workstation
• Computers
• A wide selection of microphones typical for different types of instruments
• DI unit boxes
• Microphone stands to enable engineers to place microphones at the desired locations in front of singers, instrumentalists or ensembles
• Studio monitors designed for listening to recorded mixes or tracks
• Studio monitoring headphones (typicallly closed-shell, to prevent sound from "leaking" out into the microphones)
• "On Air" or "Recording" lighted signs to remind other studio users to be quiet
• Outboard effect units, such as compressors, reverbs, or equalizers
• Music stands

A selection of instruments at a music studio, including a grand piano

Not all music studios are equipped with musical instruments. Some smaller studios do not have instruments, and bands and artists are expected to bring their own instruments, amplifiers and speakers. However, major recording studios often have a selection of instruments in their live room, typically instruments, amplifiers and speaker cabinets that are large, heavy, and difficult to transport (e.g., a Hammond organ) or infeasible (as in the case of a grand piano) to hire for a single recording session. Having musical instruments and equipment in the studio creates additional costs for a studio, as pianos have to be tuned and instruments and associated equipment needs to be maintained.

However, it makes it more convenient for recording artists, as they do not have to bring in large, heavy gear, or for guitar amps, they do not have to bring in a number of amps and cabinets. As well, less costly studio time is spent moving in gear and setting it up. Another benefit is that microphones can be set up in appropriate locations near all of the studio-owned instruments, and bass amps can have their DI units plugged into the mixing board, which speeds up set-up time.

Instruments which may be present in a studio include:

• Keyboard instruments and related keyboard gear
  • Grand piano (e.g., Steinway)
  • Hammond organ and rotating Leslie speaker
  • Fender Rhodes electric piano
  • Wurlitzer electric piano
  • MIDI keyboard or MIDI-equipped stage piano
  • Vintage synthesizers (e.g., Moog synthesizers)
  • Keyboard amplifier
• Acoustic drum kit: this may only include the wood-shelled drums and the stands. Studios typically own major brands such as Premier, Ludwig and Gretsch. Some studios have a selection of classic snares. Drummers typically prefer to use their own snare drum and cymbals
• Bass amplifier and bass speaker cabinet (e.g., a tube Ampeg SVT amp and an 8x10" cabinet)
• Guitar amplifier and guitar speaker cabinets (e.g., a Fender Twin and a Marshall tube amp and speaker stack. Tube amps made by Vox, Ampeg, and Gibson may also be available.
• Vintage guitars and basses made by Fender, Gibson, and Rickenbacker
• In rare cases, studios may have a mellotron ethnic drums, sitars, a double bass, or unusual instruments that bands might wish to try for a particular sound.

Guitarists and bassists are often expected to bring their own guitars, basses and effects pedals. Drummers often bring their own snare drum, cymbals and sticks/brushes. Musicians that play other easily transported instruments, such as instruments from the violin family, accordion, ukulele, banjo, brass horns, and woodwinds will also be expected to bring their own instruments, especially when intonation is an issue as many musicians will have adapted to the tone of a specific instrument.

The types and brands of music equipment owned by a studio depends on the styles of music for the bands and artists that typically record there. A studio that mainly records heavy metal music will be likely to have large, powerful guitar amp heads and speaker stacks (e.g., Marshall Amplification amps for guitar). In contrast, a studio which mainly records country bands will likely have a selection of smaller, vintage combo amps (e.g., 1950s Fender "tweed" combos). A studio that records a lot of 1970s-style funk may have a vintage electric piano or Clavinet.

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 by cutting a rotating cylinder (later disc) made from wax. Performers were typically grouped around a large acoustic horn (an enlarged version of the familiar phonograph horn). The acoustic energy from the voices 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. Following the invention and commercial introduction of the microphone, the electric 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 obsolete.

The Siemens Studio for Electronic Music ca. 1956.

Electrical recording was common by the early 1930s, and mastering lathes were electrically powered, but master recordings still had to be cut into a disc, by now a lacquer, also known as an Acetate 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 as the natural reverb enhanced the sound of the recording. 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, which did not allow for multitrack recording techniques, studios of the mid-20th century were designed around the concept of grouping musicians (e.g., the rhythm section or a horn section) and singers (e.g., a group of backup 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. In the 2000s, modern sound stages still sometimes use this approach for large film scoring projects that use large orchestras.

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),[4] and the 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 Abbey Road Studios 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. As the need to transfer audio material between different studios grew, there was an increasing demand for standardization in studio design across the recording industry, and Westlake Recording Studios in West Hollywood was highly influential in the 1970s in the development of standardized acoustic design.[5]

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),[6][7] and one of their earliest recording studios, "Studio A" at 799 Seventh Avenue.[4]

Donna Summer wearing headphones during a recording session in 1977

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 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.

Danny Knicely records with Furnace Mountain Band in Virginia (2012)

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, or, more rarely, on 35mm magnetic film, 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. In the 2010s, 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 used by some audiophiles and sound engineers, who believe that digitally recorded audio as sounding too harsh and who believe that tape has a "warmer" sound. The scarcity and age of analog tape machines has increased their value, as does the fact that some audio engineers still believe in recording to analog tape.