Pro Audio Reference: K

k The symbol for kilo.

K The symbol for Kilo.

K The symbol for kelvin, the SI unit of thermodynamic temperature.

K2HD (K2 High Definition) Recording Mastering. A high-end CD mastering and re-mastering technique developed by JVC that uses 24-bit, 192 kHz sampling for all mastering steps up to the final 16-bit CD pressing. Said to give the listener the best possible 16-bit CD recording.

K2-W Designation for a famous tube-based 'modern' general-purpose operational amplifier built by Philbrick beginning in 1951.

ka 1. Electronics. Abbreviation for cathode. 2. Philosophy. Egyptian concept of duality, which is also an important electronics concept — check out the link.

Kabuki Theater. A type of popular Japanese drama, evolved from the older No theater, in which elaborately costumed performers, nowadays men only, use stylized movements, dances, and songs in order to enact tragedies and comedies. [AHD]

Kahn, Al (1906-2005) American entrepreneur who cofounded Electro-Voice with Lou Burroughs.

Kaisermarsch Music. Work by Wagner for unison male voices and orchestra (1871), celebrating the German victory in the Franco-Prussian War and the election of Wilhelm I as emperor. [Sadie]

kalimba Musical Instrument. The original thumb piano.

Kaman, Charles H. (1919-2011) American musical pioneer (as well as an aeronautical engineer) who developed the Ovation ® Roundback guitar and went on to found Kaman Corporation, now KMC Music.

kamanche Musical Instruments. A bowed spike fiddle of Middle East origin.

Kámán Line Astronomy. The boundary between Earth's atmosphere and space (the edge of space) that lies roughly 100 km above sea level.

kankles Musical Instrument. Lithuanian zither.

kantor (also cantor) Christianity. Title of a church musician.

Ka-on vase A flower vase fitted with audio input ports that use the flowers as loudspeakers. Invented by Let's Corporation.

karaoke Music. 1. A music entertainment system providing prerecorded accompaniment to popular songs that a performer sings live, usually by following the words on a video screen. 2. The performance of such music. [From Japanese: kara, void, empty + oke(sutora), orchestra.] [AHD]

karaokeal amnesia "Most people don't know the complete lyrics to almost any song, particularly the ones they hold most dear." [A Dictionary of the Near Future by Douglas Coupland, NY Times, September 12, 2010.] See also: lyrical putty.

karat also carat Abbr. k or kt. A unit of measure for the fineness of gold, equal to 1/24 part. Pure gold is 24 karat; gold that is 50 percent pure is 12 karat. [AHD]

Karnaugh map Mathematics of Computing. A rectangular diagram of a logical expression drawn with overlapping rectangles representing a unique combination of the logic variables such that an intersection is shown for all combinations. The rows and columns are headed with combinations of the variables in a Gray code sequence. [IEEE]

kasik (spoon) Musical Instrument. Turkish percussion instrument shaped and played like a spoon.

Katodophone Name for a microphone without mechanical moving parts based on recording the density variations in ionized air between an anode and a cathode caused by sound waves. First used to add sound to film in 1918, invented and patented by Han Vogt, Joseph Engl and Joseph Mass Olle who formed the German film company, Tri-Ergon (translates into "a work of three.")

katzenklavier See: cat organ.

kaval Musical Instrument. Bulgarian rim-blown flute, typically made from plum tree wood..

kazoo A toy musical instrument with a membrane that produces a buzzing sound when a player hums or sings into the mouthpiece. The word origin is believed to come being imitative of its sound. [AHD]

kb See kilobit

kB See kilobyte

Kb See Kilobit

KB See Kilobyte

KCL See: Kirchoff's Current Law.

keeper A bar of material (usually soft iron) with very high magnetic permeability placed across the poles of a permanent magnet (effectively shorting out the magnetic field) to protect it from demagnetization. Most often seen on horseshoe or U-shaped magnets. [Thanks to Glenn White.]

Keith Emerson (1944-2016) Brilliant British musician composer and founding member of Emerson, Lake & Palmer.

Kellems® A registered trademark of Hubbel Inc. for their series of wire mesh grips creating strain relief between electrical cables and connectors.

Kell factor Video. After RCA researcher Ray Kell who discovered in 1934 the phenomenon that the actual human visual resolution is only about 70% of the number of physical lines used in a video system. That is, humans have a reduced visual resolution due to line-scanning structures. Visual information is lost due to the probability that some of the video information will be displayed during the retrace instead of the active portion of the scan line. Even though it may seem like half the information would be lost because there are equal number of scan and retrace lines, empirically it has been shown that about 30% is lost to this effect, yielding a Kell factor of about 0.7. (Bandwidth Versus Video Resolution, Maxim Application Note 750.)

Kellogg, Edward & Chester Rice Loudspeakers. General Electric researchers who invented and patented the moving-coil direct-radiator loudspeaker in 1925.

kelvin Abbr. K The International System unit of absolute temperature equal to 1/273.16 of the absolute temperature of the triple point of water. This unit is equal to one Celsius degree. A temperature in kelvin may be converted to Celsius by subtracting 273.16. (After First Baron Kelvin) [AHD]

Kelvin, William Thomson, First Baron (1824-1907) British physicist who developed the Kelvin scale of temperature (1848) and supervised the laying of a transatlantic cable (1866). His pioneering work in thermodynamics and electricity helped develop the law of the conservation of energy. [AHD]

Kelvin worked out an improved method for measuring the depth of the sea using piano wire and a narrow-bore glass tube, stoppered at the upper end. While experimenting with this invention, he was interrupted one day by his colleague James Prescott Joule. Looking with astonishment at the lengths of piano wire, Joule asked him what he was doing. "Sounding," said Thompson. "What note?" asked Joule. "The deep C," returned Thompson. [Bartlett's Book of Anecdotes]

Kelvin connection also 4-wire Kelvin connection A 4-wire, 2-pair, connection used to make resistance measurements that are independent of the measuring lead resistance — one pair is a current source and the other pair is a voltmeter.

kemençe (of the Black Sea) Musical Instrument. A bowed Persian folk instrument.

kena See: quena.

Kennelly, Arthur E. (1861-1939) An Iris-American engineer who was professor of electrical engineering at Harvard University and later at the Massachusetts Institute of Technology. In 1893, he presented his famous "Impedance" paper to the American Institute of Electrical Engineers. In it he demonstrated the first use of complex numbers as applied to Ohm's Law in alternating current circuit theory.

kerfuffle Fuss, commotion, disorder, agitation. [OED]

kernel Software. That portion of an operating system that is kept in main memory at all times. [IEEE]

Keronite® Name of a company and of a surface treatment of light alloys that has the potential for creating superb loudspeaker cones. For details see Steve Mowry's "The Keronite® Story".

Kerr Effect (aka Faraday Effect) Physics. If an isotropic dielectric is placed in an electric field and a beam of light is passed through the sample orthogonally to the field then the material displays birefringence. (After Rev. John Kerr, M.A., LL.D., F.R.S. [1824-1907].) This forms the basis of recordable optical discs.

Kevlar® Registered trademark of DuPont. Material invented by DuPont chemist Stephanie Kwolek. Used in loudspeaker driver cones due to its high strength-to-weight ratio.

key Music. 1. The pitch of a voice or other sound. 2. The principal tonality of a work: an etude in the key of E. 3. A tonal system consisting of seven tones in fixed relationship to a tonic, having a characteristic key signature and being the structural foundation of the bulk of Western music; tonality. [AHD]

keyable or keying Signal Processors. The ability to start or trigger a process by applying an external signal, usually to a side-chain.

key lock Music. Phrase for pitch matching two or more sources using pitch-shifting techniques. It refers to the fact that the key or pitch of the music remains the same, even though the tempo is changing.

keynote The tonic of a musical key. [AHD]

Key West audion Nickname given the first use of the audion tube by the Navy at their wireless station in Key West, Florida.

K-factor or K-rating Transformers. Transformers designed for operation in non-sinusoidal environments with non-linear loads.

KHN filter See state-variable filter.

kHz (kilohertz) One thousand (1,000) cycles per second.

kibi Symbol Ki New term standardized by the IEC as Amendment 2 to IEC 60027-2 Letter Symbols to be Used in Electrical Technology to signify binary multiples of 1024 (i.e., 2E10). Meant to distinguish between exact binary and decimal quantities, i.e., 1024 verses 1000. For example, it is now 16 kibibits, abbreviated 16 Kib, not 16 kilobits or 16 Kb.

kik Recording. Popular jargon meaning "kick" (bass) drum sound or just the drum itself.

Kilby, Jack American electrical engineer and Noble price winner for his invention of the monolithic integrated circuit while working for Texas Instruments.

kill switch DJ Mixers. Control for removing whole frequency sections like bass, mids or highs.

kilo- Abbreviated k (always lower-case). A prefix signifying one thousand (10E3).

Kilo- Abbreviated K (always upper-case). A prefix popularly used in computer work to signify multiples of 1024 (i.e., 2E10), but should use kibi. Meant to distinguish base-2 (binary) from base-10 (decimal) magnitudes. For example, a "16 K" memory is actually 16,384 bits (i.e., 16 times 1024, or 2E14), but should now read "16 Ki".

kilobit - Abbreviated kb (lower-case k and b). A term signifying one thousand bits. Also kb/s or kbps for kilobits per second.

Kilobit - Abbreviated Kb (upper-case K and lower-case b). A term signifying 1024 bits, but should use Kibibit. Also Kb/s or Kbps for Kilobits per second or Kibibits per second.

kilobyte - Abbreviated kB (lower-case k, upper case B ). A term signifying one thousand bytes. Also kB/s or kBps for kilobytes per second.

Kilobyte - Abbreviated KB (upper-case k and B). A popular term signifying 1024 bytes, but should use Kibibyte. Also KB/s or KBps for kilobytes per second or Kibibytes per second.

kilogram Abbr. kg The base unit of mass in the International System, equal to 1,000 grams (2.2046 pounds). [AHD]

kilovar A unit equal to one thousand voltamperes.

kinetoscope A motion picture system developed in 1891 by Thomas A. Edison and William Dickson, considered the predecessor of the movie projector.

Kirchoff's Current Law Abbr. KCL Electronics. The amount of current flowing into a node exactly equals the amount of current flowing out of the same node; or the sum of all currents flowing into a node equals zero. (After Gustav Robert Kirchoff.)

Kirchoff, Gustav Robert (1824-1887) German physicist noted for his research in spectrum analysis, optics, and electricity. [AHD]

Kirchoff's Voltage Law Abbr. KVL Electronics. The sum of all voltage drops and rises in a closed loop equals zero. (After Gustav Robert Kirchoff.)

Kirshner, Don (1934-2011) American record producer, manager and song publisher, as well as TV host and producer of rock concerts.

KJ (karaoke jockey) As in DJ and VJ, only different.

Klass Compaan Dutch physicist who came up with the idea for the CD in 1960. He teamed up with Philips and produced a glass prototype in 1970. See James T. Russell.

Klaus Quirini See: discotheque

Klippel Analyzer System A new loudspeaker parameter measurement tool invented and developed by Wolfgang Klippel. Theory and details are covered in his AES 2000 convention paper: Diagnosis and Remedy of Nonlinearities in Electrodynamical Transducers. AES Preprint #5261. Lots of technical application note downloads available here.

Klipsch, Paul W. (1904-2002) American engineer and inventor best know for inventing the "Klipschorn" below. He was one of the American audio pioneers. Member of the Audio Hall of Fame.

Klipschorn® A type of full-range loudspeaker developed in 1941 with a revolutionary low end (Paul W. Klipsch, "A Low Frequency Horn of Small Dimensions," JASA, Vol. 13 October 1941; U.S. Pat. Nos. 2,310,243 & 2,373,692). By using the corner of the room as an extension of the folded horn within the cabinet, it was able to reproduce low-distortion tones down to 30 Hz. The Klipschorn is claimed as the only speaker in the world that has been in continuous production since the '40s. (After Paul W. Klipsch above.)

Kloss, Henry (1929-2002) American engineer and inventor, best known for co-developing the acoustic-suspension loudspeaker (along with Edgar Villchur) and the large-screen projection television; founded four successful consumer electronics companies: Acoustic Research, KLH, Advent and Cambridge SoundWorks. Member of the Audio Hall of Fame.

kludge or kluge A system, especially a computer system, that is constituted of poorly matched elements or of elements originally intended for other applications. [AHD] Or as an article by Jackson Granholme in "Datamation" put it: "An ill-assorted collection of poorly matching parts, forming a distressing whole." [From AHD: The word kludge is not "etymologist-friendly," having many possible origins, none of which can be definitively established. This term, found frequently in the jargon of the engineering and computer professions, denotes a usually workable but makeshift system, modification, solution, or repair. Kludge has had a relatively short life (first recorded in 1962 although it is said to have been used as early as 1944 or 1945) for a word with so many possible origins. The proposed sources of the word, German klug, kluge, "intelligent, clever," or a blend of klutz and nudge or klutz and refudge, do not contain all the necessary sounds to give us the word, correctly pronounced at least. The notions that kludge may have been coined by a computer technician or that it might be the last name of a designer of graphics hardware seem belied by the possibility that it is older than such origins would allow. It seems most likely that the word kludge originally was formed during the course of a specific situation in which such a device was called for. The makers of the word, if still alive, are no doubt unaware that etymologists need information so they can stop trying to "kludge" an etymology together.]

klystron The name — from the Greek, as coined by scientists at Stanford University -- was registered by Sperry Gyroscope Company in the late 1930s for their velocity-modulated, ultra-high-frequency tube. As described by them in an ad published in a 1945 issue of Scientific American, "it is an apt description of the bunching of electrons between spaced grids within the tube." In the spirit of voluntary standardization they gave the name to the public for free use as the designation for velocity-modulated tubes of any manufacture. [Old klystron tubes make the best TV lamps.]

Knechtel, Larry (1940-2009) American musician who won a Grammy for his arrangement of Simon and Garfunkel's "Bridge Over Troubled Water." For nearly 50 years he performed live and in the studio with top-selling artists.

knee (of a curve) The point on a curve where change begins to occur; a section resembling the human knee exhibiting bending.

knife switch A form of switch in which the moving element, usually a hinged blade, enters or embraces the stationary contact clips. [IEEE]

knockout A portion of the wall of a box or cabinet so fashioned that it may be readily removed by a hammer, screwdriver, and pliers at the time of installation in order to provide a hole for the attachment of a raceway cable or fitting. [IEEE]

knoup To toll the church bell. [Kacirk]

Knowles, Hugh S. (1904-1988) American engineer and entrepreneur who founded Industrial Research Products in 1946 and Knowles Electronics in 1954.

Knuckles, Frankie (1955-2014) American DJ recognized as the "godfather of house music."

Knudsen, Vernon Oliver (1893-1974) American physicist who studied and worked under Dr. Harvey Fletcher , helped found the ASA, and was the first dean of the UCLA Physics Department, then vice chancellor of the university and finally chancellor.

kobza Musical Instrument. Ancient plucked lute (also called Thracian lyre) found in eastern europe and still manufactured in Romania (click the link for photo and history).

Kodak See Muzak.

konghou Musical Instrument. Chinese ancient instrument similar to a harp.

kora Musical Instrument. West African harp lute.

Korner Killer™ Acoustics. A trademark of RPG Diffuser Systems, Inc.

K-pop (shortened form of Korean pop) Musical genre originating in South Korea in 1992, and is now a global phenomenon.

krunk (or crunk) A hip-hop music style born in Memphis, by Three 6 Mafia in the early '90s.

kSPS (kilo samples per second) One thousand (1,000) samples per second. A measurement of data converter speed.

ku band Telecommunications. Radio frequencies band of roughly 15 GHz to 18 GHz, used for satellite telecommunications.

KUDO (K-Louver modular directivity United with DOSC waveguide technology) Loudspeakers. Designation by L-Acoustics for their line array.

Kundt's tube Named after A.A. Kundt in 1866 who developed this apparatus for measuring the speed of sound in gases. It allows visualizing acoustic standing waves.

kunstkopf Recording. The German word for an artificial recording head, used primarily for binaural recordings.

Küpfmüller, Karl (1897-1977) German engineer who was a university professor before becoming the Director of R&D at Siemens & Halske and made significant contributions to network theory, communications technology and acoustics.

kVA (kilovoltamperes) One thousand (1,000) voltamperes. See voltampere.

kvar (Pronounced kay var, with emphasis on the first syllable) a) The size or magnitude of a reactive power source, which would usually be measured in (units of) kilovar. b) Abbreviation for kilovar, a unit of reactive power. [ IEEE Std 1531]

KVL See Kirchoff's Voltage Law.

KVM (keyboard/video/mouse) Computers. An adapter box that allows multiple computers to share the same keyboard, monitor and mouse.

K-weighting See: weighting filters.

KZK (Khokhlov-Zabolotskaya-Kuznetsov) equation Nonlinear Acoustics. A one-way propagation equation for narrow-angle beams of sound, similar to the nonlinear propagation equation but not limited to lossless fluids. [Morfey]

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