0 dBFS – a digital audio reference level equal to full scale. 0 dBFS is the absolute maximum voltage level that can be converted by an A/D converter and has a digital code consisting of all 1s. Therefore, no digital level can exceed 0 dBFS. When voltage exceeds that level clipping occurs. dB FS is used to express the level of a digital signal, and should not be for analog signals. Sometimes designated dB(FS) or dB Full Scale.
0 dBm – a power level of 1 mw, which equals a voltage of 0.775 V into a 600-ohm load, the common load for professional audio equipment when this standard was set. The standard of 0 dBu was also chosen to equals 0 dBm. See dbm and dBu.
0 VU – the target level for audio signals being measured with a VU meter, which is sometimes indicated as 100%. It is equivalent to +4 dBu with a 1000-Hz tone. Sometimes incorrectly indicated as 0 dBVU.
⅛ space – refers to a loudspeaker that is placed in a corner where three surfaces join, such as two walls and a floor. Sound sources placed near surfaces project more energy toward the listening space. A speaker placed into ⅛ space produces approximately 3 dB more sound power than one in quarter space and 6 dB more than one in half space.
¼-wavelength null – the point at which phase cancellation occurs when a soundwave reflects off a wall and interferes with another soundwave that is ¼ of the wavelength of the first. This often occurs when a monitor or speaker is placed a short distance from the front wall. The null can be more than 20 dB deep, so speaker placement is critical for good bass response. The frequency of the front-wall null can be calculated by dividing the speed of sound by 4 and dividing that by the distance from the wall to the voice coil. Moving the monitor toward the wall increases the offending frequency, but also increases the overall bass response as it approaches half space condition. The variation in frequency with distance of the monitor from the wall is shown in the table below. The frequency of the rear-wall null depends on the position of the listener. Nulls should be controlled using acoustic treatment. Additional nulls occur whenever the wavelength of a harmonic is a fractional multiple of the fundamental wavelength having an odd number in the numerator. See also ¾-wavelength null.
10-dB rule – a general rule of thumb that states when using multiple microphones in close proximity, there should be at least a 10-dB signal difference between them to avoid phase problems. See also three-to-one rule.
-10 dBV – the standard voltage reference level for consumer audio devices equal to 0.316 Vrms, although it can be found a some pro audio gear. When solid state audio equipment was first introduced, some less expensive amplifiers had performance issues, such as lower slew rates. Establishing an operating level for consumer gear lower than the professional standard of +4 dBu allowed the consumer gear to have acceptable performance without significantly increasing the cost.
13-pin cable – a cable used with guitars having divided or hexaphonic pickup systems. The output can be connected to a guitar pitch-to-MIDI converter, a guitar synthesizer, or a guitar modeler system. The cable carries the output from each of the six strings or the hex pickup and the signal from the regular pickups, as well as several control signals and phantom power, if available. The cable does not carry MIDI data, but requires a pitch-to-MIDI converter.
16 x 9 (16:9) – the standard aspect ratio for an HDTV screen, also expressed as 1.78:1, meaning the screen has 1.78 units of horizontal width for every 1 unit of vertical height. Video and TV images using other aspect ratios will be displayed on an 16 x 9 screen either with black bars on the top and bottom of the image (letterboxing), with black bars on the sides of the image (pillarboxing), or with bars on all four sides (windowboxing). Standard-definition TV had a 4 x 3 aspect ratio.
180-gram vinyl – an LP that is thicker having 180 g of vinyl per disc instead of the normal 120 g to 140 g. These discs are considered to be audiophile grade since they resist warping and some claim they have other sonic improvements. An even higher grade is the 200-gram disc.
1080i – the designation for a high-definition television broadcast standard that provides a picture with an interlaced image and 1080 lines of vertical resolution, one of the standards of the ATSC. It uses a widescreen aspect ratio of 16:9 (1920 pixels x 1080 lines) with 50 or 60 interlaced fields per second. Sometimes shown as 1080I. Also called full high-definition (FHD).
1080p – the designation for a high-definition television picture with a progressive scan image and 1080 lines of vertical resolution. It uses a widescreen aspect ratio of 16:9 (1920 pixels x 1080 lines) with 50 or 60 interlaced fields per second. 1080p is usually provided from a Blu-ray disc, as there is currently no progressive-scan broadcast standard. Only television sets designed for progressive scan can display this mode. Sometimes shown as 1080P. Also called full high-definition (FHD).
2-pop – a tone used in television and filmmaking production that provides a method of synchronizing sound and picture. It uses a 1000-Hz tone at a level of -20 dB that is one frame long and is placed 2 seconds before the start of the program.
2.4 GHz band – the range of radio frequencies from 2.4 GHz to 2.4835 GHz, part of the ISM (Industrial, Scientific, and Medical) band of frequencies within the UHF region. Among other things, it is used by some manufacturers for the transmission of wireless microphone signals. See also VHF, 700 MHz band, 5 GHz band, and 6 GHz band.
-20 dBFS – the unofficial standard for the level represented as 0 VU (an output of +4 dBu). This is the standard used by NPR as well as most video and film production companies in the US, but some manufacturers use other values. In the UK, a level of -18 dBFS is often used.
24.1.10 – one configuration of speakers for immersive sound used in theaters. It consists of 24 front, side, and back speakers, one effects channel (the “.1”), and ten height channels (the “.10”). Other configurations are also used for theaters, but home systems typically would use 5.1.2, 5.1.4, 7.1.2, 7.1.4, 9.1.2, or 9.1.4.
3D sound – a three-dimensional effect, in which sound can come from anywhere—directly behind to directly overhead to directly in front and all points to the left and right of the listener. Also called periphonic sound. Sometimes shown as 3-D sound.
3LCD – the brand name of a technology used in many videoprojectors that uses three LCD chips (one for each primary color: red, green, and blue). Although it was developed by Epson in the 1980s, it is marketed by 3LCD, a consortium of projector manufacturers that have licensed the technology.
3M Company – a corporation based in Maplewood, Minnesota, that was formerly known as the Minnesota Mining and Manufacturing Company, which produces a wide range of products, including adhesives, abrasives, laminates, electronic materials, medical products, and optical films. For many years it was known in the recording business as one of the main suppliers of magnetic recording tape.
3-to-1 rule or 3:1 rule – (1) A rule of thumb that states when two microphones are used to record a source, the microphones should be separated by at least three times the microphone-to-source distance. If you are recording two different sources, each microphone should be three times the distance from each other as the distance each mic is from its respective source. This rule is designed to minimize phase problems. (2) Another 3:1 rule states that a distant microphone should be 3 times as far away from the source as a close microphone. For example, if the mic is placed 12 inches away from an acoustic guitar, the room microphones should be at least 3 times that distance away from the first mic (36 inches) or 48 inches from the guitar. Sometimes called the rule of three, the 4-to-1 rule, or the 4:1 rule. See also 10-dB rule.
3-track – the first commercial multitrackanalogrecording tape format introduced by by Ampex in the early 1960s. They were used for recording popular music in which the lead vocal was recorded on one track and the backing instruments were recorded on the other two tracks. These tracks could be used for overdubbing or to create a full stereo backing track. Three-track recorders were in widespread use in recording studios until the mid-1960s, when 4-track recorders came into use. See also chart of multitrack tape formats.
3:2 pull down – a method of displaying movie film with a frame rate of 24 frames per second (fps) so it is compatible with 30-fps video and television broadcasts. With 3:2 pull down, the first frame of film is shown twice followed by the second frame shown three times before repeating the process with the third frame. Also called 3/2 pull down, 3-2 pull down, 3-to-2 pull down, 2:3 pull down, 2/3 pull down, 2-3 pull down, 2-to3 pull down, and 2:3:2:3 pull down, as well as spelled pulldown and pull-down. See drop-frame time code.
32-bit floating point – a method of expressing numeric values using floating point notation in the binary number system in which 23 bits are used to represent a number, 8 bits represent an exponent, and 1 bit represents the sign (positive or negative). While a 32-bit fixed point number (a number that has a fixed number of digits) can have 232 values, a 32-bit floating point number can have almost an unlimited number of values (positive and negative values from roughly 10-38 to 1038). Audio files with a 32-bit floating point bit depth have a theoretical dynamic range of about 1680 dB compared to 144 dB with 24-bit files. Besides increasing headroom, a 32-bit floating point format helps avoid clipping and rounding errors during signal processing and introduces less noise when dithering. However, 32-bit files are 50% bigger than 24-bit files.
33⅓ rpm – The standard playing speed used for the vinyl long-play (LP) record. The speed was created by Western Electric in 1925 for the film industry. Before soundtracks were added directly to the film, the sound was reproduced from records. Since a 78-rpm record only lasted 2 minutes, a slower speed was needed for use with an 11-minute movie reel. A synchronous motor operating on 60-cycle power with a gear ratio of 108 produces 33⅓ rpm. When the soundtrack was added to the film stock, this record speed was retained for other purposes. (2) Often used as a synonym for a 12-inch vinyl LP record, usually without the “rpm”. Sometimes called 33-rpm.
4-track – an analogrecording tape format in which there are four parallel tracks on the tape, with each track taking up ¼ of the tape width. Originally four-track was on reel-to-reeltape machines using ¼-inch tape. Introduced in the early 1960s, these machines were used in recording studios as multitrack recorders with all four tracks being recorded in the same direction. This format was the primary recording format until it began to be replaced by 8-track recorders usually on ½-inch tape in the early 1970s. Four-track recorders for the consumer market used ¼-inch tape for stereo recording and playback. The stereo signal was on tracks 1 and 3. At the end of the tape, the reel could be flipped over with tracks 2 and 4 now in the 1 and 3 position. Cassette tapes also had four tracks, but on ⅛-inch tape. Also called quarter-track. See also chart of multitrack tape formats.
4-track cartridge – a short-lived format for analogtape reproduction used primarily in automobiles developed by Carl Muntz. It used an endless-loop ¼-inch-wide (6.4 mm) analog recording tape, formatted into 4 tracks played two at a time (stereo). Unlike the 8-track cartridge with which it competed and looked similar to, it did not automatically change tracks between programs, but had to be switched manually. It was soon replaced by the cassette. Also called a Muntz Stereo-Pak. See also Fidelipac.
4:2:4 – a method of matrixing a 4-channel audio signal (left, right, center, and sides) into a two-channel, stereo-compatible format that can be broadcast or recorded and subsequently decoded back into four channels. See Dolby Motion Picture 4:2:4.
4 x 3 (4:3) – the standard aspect ratio for a standard-definition TV screen (PAL and NTSC), also expressed as 1.33:1, meaning the screen has 1.33 units of horizontal width for every 1 unit of vertical height. Video and TV images using an 4 x 3 aspect ratio will be displayed on an HDTV screen with black bars on the sides of the image (pillarboxing). HDTV has a 16 x 9 aspect ratio.
45 rpm – (1) The standard playing speed for the 7-inch vinylsingle. The 45-rpm single had a large spindle opening of about 1.5 inches because the automation of early juke boxes could handle them easier. (2) Often used as a synonym for a 7-inch vinyl record, usually without the “rpm”.
480i – the designation for a television picture with an interlaced image with 480 lines of vertical resolution scanned alternately. It is the NTSC system or the DTV version having the same specifications, with the “i” meaning interlaced. Although NTSC has 525 lines, the digital version only uses 483. This is considered to be standard-definition television, along with 576i for PAL/SECAM. Sometimes shown as 480I.
5.1 – the surround sound format developed by MPEG for digital soundtrack encoding for film, videotapes, DVD, and HDTV broadcasts. The “5” refers to the five discrete channels: left front, right front, center front, left surround, and right surround. The “.1” refers to the subwoofer channel or the special effects/feature channel.
500 series – an industry standard developed by API for mounting modules, such as mic preamps, equalizers, compressor, limiters, etc. from a large number of manufacturers. It consists of a hardware frame (called a 500-series chassis or rack) into which 500-series modules are mounted. The chassis typically provides power for the installed modules, input and output connections, and sometimes additional proprietary functions. The 500-series chasses are available in sizes to hold various numbers of modules. They fit in 19-inch 3Uracks or in tabletop or portable formats. The slang for a modules is a lunchbox, but API has now registered the trademark as API Lunchbox®.
576i – the designation for a television picture with an interlaced image with 576 lines of vertical resolution scanned alternately, with the “i” meaning interlaced. It is the system used in much of the world where the electric power is 50 Hz, typically where PAL/SECAM was the analog standard with 625 lines, although only 576 lines were used in the image. This is considered to be standard-definition television, along with 480i for NTSC. Sometimes shown as 576I.
6 GHz band – The range of radio frequencies from 5.925 GHZ to 6.425 GHz, a part of the HF region. Among other things, it is used by some manufacturers for the transmission of wireless microphone signals. See also VHF, UHF, 700 MHz band, and 2.4 GHz band.
78-rpm – (1) The standard playing speed for the original phonographrecord, which was standardized around 1925. (Prior to that there was no standard, and recording speeds varied from 60 to over 100 rpm.) The exact speed depends upon the frequency of the acpower. For countries with 60-Hz power, the speed was 78.261 rpm, which resulted from a 3600-rpm synchronous motor having a gear reduction of 46:1. For 50-Hz power the actual speed was 77.922 rpm, the results of a 3000-rpm synchronous motor being reduced by 77:2. (2) Often used as a synonym for a 10-inch shellac record, usually without the “rpm”.
700 MHz band – The range of radio frequencies from 698 MHz to 806 MHz, part of the UHF region. Although currently banned by the FCC for use by wireless microphones, the use of this band was allowed for this purpose prior to 2010. See also VHF, 6 GHz band, and 2.4 GHz band.
8-mm video – a general term referring to three different videocassette formats: Video 8 (analog), Hi 8 (analog), and Digital 8 (digital). These formats were used primarily by amateur camcorder users, but were occasionally used in professional television production. The three cassettes all use 8-mm wide recording tape and are very similar in size, but are not truly compatible with one another and use different encoding techniques. The 8-mm tape size was a smaller successor to the 12-mm Betamax format, chosen to compete with VHS-C compact camcorders.
8-track – an analogrecording tape format in which there are eight parallel tracks usually on ½-inch tape used for multitrack recordings. The first 8-track recorder was specially made for Les Paul by Ampex, and was installed in his home recording studio in 1957. However, this format did not come into widespread use until the 1970s. Within a few years, 16-tracks, then 24-tracks, and even 32-tracks became the common formats. Tape widths also increased from ½-inch to 1-inch and then 2-inch. See also chart of multitrack tape formats.
8-track cartridge – a popular but short-lived format for analogtape reproduction used primarily in automobiles. It used an endless-loop ¼-inch-wide (6.4 mm) analog recording tape, formatted into 8 tracks played two at a time (stereo). At the end of each program, it switched to the next track automatically, unlike the similar-appearing 4-track cartridge with which it competed that had to be switched manually. It was soon replaced by the cassette. Also called Stereo 8, 8-track tape, (or simply 8-track), and Lear cartridge after it inventor, William Powell Lear, who designed the LearJet. See also Fidelipac and Quad-8, the quadraphonic version of the 8-track cartridge.
8va – abbreviation for All' ottava alta. See ottava.
8va alta – abbreviation for All' ottava alta. See ottava.
8va bassa – abbreviation for All' ottava bassa. See ottava.
8vb – abbreviation for All' ottava bassa. See ottava.
83 dB SPL – the standard listening level for motion pictures. This level was originally proposed by Dolby Labs in the mid-1970s and was originally used to calibrate 0 VU when using analogmagnetic film. When film converted to digital technology, the VU meter was rapidly replaced by the peak program meter. For home theater systems, many authorities recommend lowering the listening level by 6 dB, because a typical home listening room does not accomodate high SPLs and wide dynamic range. It has been suggested that the same level should be used for mixing audio, especially for pop music. To calibrate a monitor to the movie-listening level, play a standardized pink noise calibration signal with an amplitude of -20 dB FS RMS through one monitoring channel at a time. Adjust the monitor gain to yield 83 dB SPL using a C-weightedsound level meter with a slow response. Set the gain to 0 dB as the reference. For most music, the monitor gain will be 6 dB below this reference.
802.11 – a family of specifications established by the IEEE for use by wirelesslocal area networks (LANs). There are a number of specifications for 802.11, each having a unique set of transmission methods and data rates. These include 802.11a, 802.11b, 802.11g, and 802.11n. See table below. See also Wi-Fi.
Note: We believe this is the largest dictionary (glossary) of terms specific to usage within the recording industry that is currently available on the internet, with more than 7,800 entries, nearly 600 illustrations, and dozens of tables. Some of the terms have different or additional meanings in other situations, especially within the electronic, automotive, scientific, and computer industries. Of necessity there are obvious overlaps into other fields such as music, electronics, and computers, but such excursions are limited to information deemed pertinent to the knowledge required to operate and/or participate effectively in the workings of a recording studio. Also included are terms related to sound reinforcement (live performances) including wireless microphone technology because a working knowledge of that terminology is necessary for recording at live performance venues. Because recording studios also record audio for video and motion pictures (films), some terminology from those fields is included. Some scientific terms are included because they help explain studio terminology. For example, electromagnetism explains how microphones, loudspeakers, and guitar pickups work. Knowledge of radio waves and the radio frequency spectrum is needed to explain wireless devices. Any trademarks or trade names mentioned belong to their respective owners. The information contained in this dictionary is believed to be accurate at the time of publication. This information is subject to change without notice. The information was obtained from and cross-checked with a variety of sources that are believed to be reliable. However, Los Senderos Studio, LLC does not guarantee the accuracy or completeness of the information contained herein. Please contact us to report any errors, omissions, discrepancies, or broken links. Los Senderos Studio shall not be responsible for any consequences or damages arising out of the use of this information. Nothing in this glossary should be interpreted as legal advice. For a glossary providing information on legal and business matters for musicians, we suggest you consult Musicians Business Dictionary.
A note on alphabetical order: The terms in this glossary are alphabetical without regard to spaces and punctuation. For example, AM Radio follows amplitude. While this may seem to be at odds with other conventions, it eliminates confusion with words such as pickup, which is sometimes written as pick up or pick-up. The entries on the number page (0-9) are listed in increasing value within each digit. For example, all of the entries beginning with 1 are listed before those starting with 2. For Greek letters (α-ω), the entries are in Greek alphabetical order.