B
B-3 Music. Famous organ developed by Laurens Hammond in 1954 and when combined with a Leslie® rotating speaker became a jazz, R&B, and rock 'n' roll staple.
babbling tributary In LAN technology, a workstation that constantly sends meaningless messages.
babel Loud, confused, or disagreeable sound that stresses confusion of vocal sounds arising from simultaneous utterance and random mixture of languages. After Babel, the biblical city (now thought to be Babylon) in Shinar where God confounded a presumptuous attempt to build a tower into heaven by confusing the language of its builders into many mutually incomprehensible languages. [AHD]
back-EMF (back-electromotive force) See also EMF. Literally, back-voltage, is a phenomena found in all moving-coil electromagnetic systems, but for audio is most often used with respect to loudspeaker operation. This term describes the action where, after the signal stops, the speaker cone continues moving, causing the voice coil to move through the magnetic field (now acting like a microphone), creating a new voltage that tries to drive the cable back to the power amplifier's output. If the loudspeaker is allowed to do this, the cone flops around like a dying fish. It does not sound good. The only way to stop back-emf is to make the loudspeaker "see" a dead short, i.e., zero ohms looking backward, or as close to it as possible. See damping factor.
background music Officially music without lyrics and not performed by the original artist, used as an alternative to silence. Contrast with foreground music.
backward masking See temporal masking.
baffle Loudspeakers. In its simplest form, the main speaker mounting board in a cabinet, whose primary purpose is to separate the front and rear sound waves, from here it becomes a very complex subject.
Baker clamp Electronics. A circuit technique dating from the early '50s using a diode as a clamp to prevent deep transistor saturation by providing a path for excessive base drive current. Recently used by National Semiconductor in a popular audio power amplifier IC to aid in fast recovery from peak overloads. Hit the link for details.
baking Sound Recording. The name for the process required for old analog tapes where they must be put into an oven and "baked" to remove moisture and prevent the oxide from shedding onto the tape heads.
balance control A control found most commonly on professional and consumer stereo preamplifiers, used to change the relative loudness (power) between the left and right channels. Attenuating the opposite channel makes one channel (apparently) louder. This is most often done (in analog designs) with a dual potentiometer with an "M-N taper." An M-N taper consists of a "shorted" output for the first 50% of travel and then a linear taper for the last 50% of travel, operating oppositely for each channel. Therefore, with the control in its center detent position, there is no attenuation of either channel. Rotating it away from the center position causes one channel to be attenuated, while having no effect on the other channel, and vice-versa. Contrast with pan and crossfade controls.
balanced line The IEC standard on amplifiers explains a balanced interface by saying that "The purpose of a balanced interface is to transfer a desired signal as a differential voltage on two signal lines." (IEC 60268-3:2001, page 111). It goes on to explain "... only the common-mode impedance balance of the driver, line, and receiver play a role in noise or interference rejection. This noise or interference rejection property is independent of the presence of a desired differential signal. Therefore, it can make no difference whether the desired signal exists entirely on one line, as a greater voltage on one line than the other, or as equal voltage on both of them."
Balanced lines are the preferred method (for hum free) interconnecting of sound systems using a shielded twisted-pair. Because of its superior noise immunity, balanced lines also find use in interconnecting data signals, e.g., RS-422, and digital audio, e.g., AES/EBU. The principal behind balanced lines is that the signal is transmitted over one wire and received back on another wire. The shield does not carry any information, thus it is free to function as a true shield, but must be earth grounded at each end to be successful. (For a detailed tutorial on proper grounding practices, see RaneNote Sound System Interconnection) This circuit's shining virtue is its great common-mode noise rejection ability. The concept here relies on induced noise showing up equally (or common) on each wire. It is mainly due to EMI (electromagnetic interference: passing through or near magnetic fields), RFI (radio frequency interference: strong broadcast signals), noisy ground references, or a combination of all three. A true balanced line exhibits exactly equal impedance from each line relative to ground, guaranteeing equal noise susceptibility. Since the balanced input stage amplifies only the difference between the lines, it rejects everything else (noise) that is common to the lines.
Ball, Roland Sherwood "Ernie" (1930-2004) American musician/entrepreneur who developed guitar strings and accessories into an art form.
ballistics See meter ballistics.
balun (balanced-unbalanced) A jargon term originally popularized by radio engineers referring to the balanced to unbalanced transformer used to interface with the radio antenna. Today, expanded to refer to any interface (usually a transformer) between balanced and unbalanced lines or circuitry; may also provide impedance transformation, as 300 ohm balanced to 75 ohm unbalanced, or vice versa. Another popular use is in transitioning between balanced twisted-pair and an unbalanced coaxial cable.
banana jack or banana plug See connectors.
band-limiting filters A low-pass and a high-pass filter in series, acting together to restrict (limit) the overall bandwidth of a system.
bandoneon Musical Instrument. A small accordion especially popular in Latin America. [AHD]
bandpass filter A filter that has a finite passband, neither of the cutoff frequencies being zero or infinite. The bandpass frequencies are normally associated with frequencies that define the half power points, i.e. the -3 dB points. See Figure 1 of the RaneNote Constant-Q Graphic Equalizers.
bandwidth Abbr. BW 1. Electronic filters The numerical difference between the upper and lower -3 dB points of a band of audio frequencies. Used to figure the Q, or quality factor, for a filter. See Figure 1 of RaneNote Constant-Q Graphic Equalizers; also download "Bandwidth vs. Q Calculator" as a zipped Microsoft Excel spreadsheet in the Rane Library. 2. Telecommunications The size of the communications channel. In analog communications, bandwidth is measured in Hertz (Hz), while digital communications measures bandwidth (data transfer rate) in bits per second. For example, an analog telephone channel has a bandwidth of 4,000 Hz, while a digitally coded telephone channel has a bandwidth of 64 kilobits/second. See the RaneNote Audio Specifications.
banjo "I can see fiddling around with a banjo, but how do you banjo around with a fiddle?" -- Duncan Purney [from Barber]
bar A unit of pressure equal to one million dynes per square centimeter. (Yeah, I know, you expected some wiseacre response, but you ain't gonna get it.)
Bara, Theda (1890-1955) Anagram of "Arab Death," used as a pseudonym by the Cincinnati-born, Hollywood actress Theodosia Goodman in the 1920s, who became the first woman movie star.
barberpole tone (or effect) See Shepard function generator.
barber's music Used to describe non-professional music named after the fact that barber's shops used to have a guitar or other acoustic instrument on hand for customer's use while waiting. [Kacirk]
Baroque 1. Music: of, relating to, or characteristic of a style of composition that flourished in Europe from about 1600 to 1750, marked by chromaticism, strict forms, and elaborate ornamentation. [AHD] 2. When you are out of Monet. (Thanks JF and I'll never tell.)
barrelhouse Style of boogie piano playing. [Decharne]
barrier strips Same as terminal strips, see connectors.
Barron, Louis & Bebe (Louis: 1920-1989; Bebe:1925-2008) American husband and wife team that composed the first electronic-music score featured in the movie, Forbidden Planet, in 1956.
baseband A transmission medium with capacity for one channel only. Typically found in local area networks (LANs). In baseband LANs, the entire bandwidth, or capacity, of the cable is used to transmit a single digital signal. Everything on that cable (transmitted or received) must use that one channel, which is very fast, so each device needs only to use that high speed channel for only a little of the time. Therefore all attached devices (printers, computers, databases) share by taking turns using the same cable. Baseband as used in videoconferencing means audio and video signals are transmitted over separate cables. Contrast with broadband
baseband signaling Transmission of a digital or analog signal at its original frequencies; i.e., a signal in its original form, not changed by modulation.
BASH® (Bridged Amplifier Switching Hybrid) Audio Amplifiers. The registered trademark of Indigo, an OEM company, for their patented (U.S. 5,075,634 & U.S. 5,510,753) Class H power amplifier technology that uses a fast-response, pulse-width modulated power supply and a linear Class AB amplifier. BASH modules are found in many powered loudspeakers from Cambridge Audio to Pioneer to Tannoy.
bass management Home Cinema. A circuit that sums all the frequencies below 80Hz from the main channels and the signal from the LFE channel and delivers it (normally) to the subwoofer. Compare with LFE.
bass ratio (BR) Acoustics. An objective measure of sound "warmth." See Concert Hall Acoustics.
bass reflex Loudspeakers. Invented by Thuras in 1930, a type of cabinet design featuring a "port" (a vent or opening of any shape) on the baffle to allow the rear sound wave to exit (in phase -- that is the trick) with the front wave. Originally a trademark of the Jensen Company in the 1930s. [White], this popular design is also called a vented loudspeaker.
bathythermograph Acoustics. A device used in underwater acoustics to measure water temperature at different depths for the purpose of determining the velocity of sound in seawater. See XBT.
battery Electronics. Invented and named by Benjamin Franklin in the 1748. He named his device for storing electrical charge for their resemblance to rows of guns.
battle axe Musician slang for a trumpet. [Decharne]
baud rate (pronounced "bawd"; after Baudot Code named for the French telegrapher Emile Baudot, 1845-1903) The transmitted signaling speed, or keying rate of a modem. Often confused with bit rate. Bit rate and baud rate are NOT synonymous and shall not be interchanged in usage. For example, one baud equals one half dot cycle per second in Morse code, one bit per second in a train of binary signals, and one 3-bit value per second in a train of signals each of which can assume one of 8 different states, and so on - all brought to you by the magic of advanced coding techniques that allow more than one bit per baud. Preferred usage is bit rate, with baud used only when the details of a modem are specified.
Bauer, Benjamin (1913-1979) Russian-American engineer who made powerful contributions to the development of many electroacoustic devices including microphones (see: Unidyne), phonograph pickups and tape recording heads. He worked for Shure from 1936 (as a co-op student) to 1957 (leaving as vice president), then CBS Laboratories as vice president.
Baxandall tone controls The most common form of active bass and treble tone control circuit based upon British engineer P.J. Baxandall's paper "Negative Feedback Tone Control -- Independent Variation of Bass and Treble Without Switches," Wireless World, vol. 58, no. 10, October 1952, p. 402. The Baxandall design is distinguished by having very low harmonic distortion due to the use of negative feedback.
bazouki See bouzouki.
BCC (binaural cue coding) Audio Compression. An audio coding technology.
BCD 1. (binary-coded decimal) Pertains to a number system where each decimal digit is separately represented by a 4-bit binary code; for example, the decimal number 23 is represented as 0010 0011 (2 = 0010 and 3 = 0011, grouped together as shown), while in straight binary notation, 23 is represented as 10111. 2. (binary-coded digit) A digit of any number system that is represented as a fixed number of binary digits; from the previous example, the decimal digit 23 is represented as 10111.
beamforming Popular buzz word in audio pick-ups for teleconferencing. Makes use of spatial filters and arrays. Nice explanation by Greg Allen and a teleconferencing demo by Koen Eneman.
beat Physics. To cause a reference wave to combine with a second wave so that the frequency of the second wave can be studied through time variations in the amplitude of the combination. [AHD]
beatboxing Hip-Hop. Using the mouth, throat and nasal cavity as a vocal percussion instrument to create hip hop drum sounds similar to record scratching.
beat frequency Equal to the absolute value of the difference in frequency of two waves beating together (see "beat" above).
Beat Generation The story goes like this ...
In The Origins of the Beat Generation Jack Kerouac (1922-1969) recalled how he borrowed the term that labeled an entire decade from a broken-down drug addict named Herbert Huncke and how he then went on to use it himself. "John Clellon Holmes ... and I were sitting around trying to think up the meaning of the Lost Generation and the subsequent existentialism and I said, 'You know, this is really a beat generation': and he leapt up and said, 'that's it, that's right.'" [Bartlett's Book of Anecdotes] See Generation X.
beat matching or beat mixing Used by disc jockeys to match beats to produce a seamless segue, or transition, between songs, or by turntablists between segments of different songs being mixed together. See Disc Jockey 101 & DJ Mixing Tips and Trix for mixing, and Beat Matching Tips for matching.
Beat me daddy, eight to the bar. Play some boogie-woogie for me. (The left-hand bass lines in typical boogie-woogie piano feature a driving, eight-to-the-bar rhythm.) [Decharne]
bebop Modern jazz style developed by Charlie Parker, Dizzy Gillespie and others in the early 1940s. Dizzy put out a single called "Bebop" in 1945 and also released "He Beeped When He Shoulda Bopped," in 1946. [Decharne] See bop.
Begun, Semi Joseph (1905-1995) Born in German, he immigrated to the U.S. in 1935 and pioneered magnetic tape recording. He wrote the first book published on magnetic recording and invented many recording products including the first consumer tape recorder as well as developing the technology that gave birth to the Black Box flight data recorder. Subject of a fascinating book by Mark Clark.
bel Abbr. b, B Ten decibels. [After Alexander Graham Bell.] The Bel was the amount a signal dropped in level over a one-mile distance of telephone wire. See decibel.
Belchfire® Series Term coined by Crown International for their mythical power amplifier, the BF-6000SUX. Based on original research into the first principles of teramagnostriction quasar-quadrature, the BF-6000SUX could have changed the design of all future power amps, but it didn't. In spite of Crown's leap forward into the past of technical declination, the marketplace categorically stated that it did not want 6,000 watts per channel in only one rack space - in spite of its six-foot depth and 206 pounds weight. The only known use of a BF-6000SUX was to drive the experimental Electro-Voice Rearaxial Softspeaker, when Rane demoed their PI 14 Pseudoacoustic Infector using Jensen's JE-EP-ERs Multi-denomial Transpedance Informer for coupling -- but many consider that only hearsay.
Bell, Alexander Graham (1847-1922) Scottish-born American inventor of the telephone. The first demonstration of electrical transmission of speech by his apparatus took place in 1876. Bell also invented the audiometer, an early hearing aid, and improved the phonograph. [AHD]
belly fiddle Guitar. [Decharne]
BEM (boundary element modeling) Acoustics. A mathematical modeling method using only a mesh of the surface of a wave, making computations easier and faster.
benders or bending See circuit-bending.
bending wave physics (also known as Distributed Mode Loudspeakers or DML) Loudspeakers. The latest trend in flat panel loudspeaker innovations based on the bending wave principal. Its simplest form consists of a small driver and a large thin panel. The driver coil excites the panel but due to the large flat surface, it does not move in and out but rather "bends"- that is, deforms in a bending wave. This wave travels throughout the panel provoking 360-degree radiation of sound in the process -- very different from the way a conventional loudspeaker cone produces sound by "pushing" air. Careful and complex design of the rigidity of the thin flexible panel allows it to increase from the middle to the edges at an equal ratio. This allows one panel to control most of the audio range, thus eliminating multiple drivers and crossover networks. See NXT and Fraunhofer IDMT for examples, and Colloms for theory. Also see Peter Dick's bending wave converter.
Benten or Ben Zai Ten Japanese Deity. Goddess of music. The name of one of the Seven Gods of Good Fortune, the goddess of music, art, happiness and love.
BeOS (Be operating system) An operating system (OS) developed by Be Incorporated in 1996, called the first true "media OS."
BER (bit error ratio) (also called bit error rate) 1. The ratio of the number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period. 2. The number of bits processed before an erroneous bit is found (e.g., 10E13), or the frequency of erroneous bits (e.g., 10E-13).
Berliner, Emil (1851-1929) German-born American inventor who made important contributions to telephone technology and developed the phonograph record disc.
Bessel crossover A type of crossover utilizing low-pass filter design characterized by having a linear phase response (or maximally flat phase response), but also a monotonically decreasing passband amplitude response (which means it starts rolling off at DC and continues throughout the passband). Linear phase response (e.g., a linear plot of phase shift vs. frequency produces a straight line) results in constant time-delay (all frequencies within the passband are delayed the same amount). Consequently the value of linear phase is it reproduces a near-perfect step response, i.e., there is no overshoot or ringing resulting from a sudden transition between signal levels. The drawback is a sluggish roll-off rate. For example, for the same circuit complexity a Butterworth response rolls off nearly three times as fast. This circuit is based upon Bessel polynomials; however, the filters whose network functions use these polynomials are correctly called Thompson filters [W.E. Thomson, "Delay Networks Having Maximally Flat Frequency Characteristics," Proc. IEEE, part 3, vol. 96. Nov 1949, pp. 487-490]. The fact that we do not refer to these as Thompson crossovers demonstrates, once again, that we do not live in a fair world. See Ray Miller's Bessel Filter Crossover and Its Relation to Other Types.
B-field See magnetic flux density.
biamp, biamplified, or biamplification Term used to refer to a 2-way active crossover where the audio signal is split into two paths, and using separate power amplifier channels for each driver.
bidirectional microphone See: microphone polar response.
bilabial Phonology. Pronounced or articulated with both lips, as the consonants b, p, m, and w. [AHD]
bipolar transistor Pertaining to a semiconductor technology in which transistors are built from alternating layers of positively and negatively doped semiconductors material. [IEEE]
BICSI® (Building Industry Consulting Services, International) A telecommunications association that is a worldwide resource for technical publications, training, conferences, and registration programs for low-voltage cabling distribution design and installation.
BIEM (Bureau International des Sociétés Gérant les Droits d'Enregistrement et de Reproduction Mécanique) An international organization representing mechanical rights societies found in most countries. They license the reproduction of songs (including musical, literary and dramatic works). Their members are composers, authors and publishers and their clients are record companies and other users of recorded music. They also license the downloading of music via the Internet.
bifilar windings A term most often associated (in the pro audio industry) with audio transformer design describing the winding technique of laying two wires side-by-side, providing essentially unity coupling, thus reducing leakage inductance to negligible amounts. Literally two threads from Latin bi- two, and filum thread.
bigit Very early contraction term for "binary digit," now obsolete. (Mentioned by Edmund C. Berkeley in his book The Computer Revolution, Doubleday, 1962, page 234.) See bit.
bilinear transform A mathematical method used in the transformation of a continuous time (analog) function into an equivalent discrete time (digital) function. Fundamentally important for the design of digital filters. A bilinear transform ensures that a stable analog filter results in a stable digital filter, and it exactly preserves the frequency-domain characteristics, albeit with frequency compression.
bimorph Piezoelectric Microphones. A cantilever device having two active piezoelectric layers where an electrical field causes one layer to bend out and the other layer to bend in. Compare with: unimorph.
binary A condition in which there are two possible states; for example, the binary number system (base-2) using the digits 0 and 1. See the RaneNote Digital Dharma of Audio A/D Converters.
binary logarithm A logarithm based on the powers of 2 (aka base 2).
binaural cue coding See BCC.
binaural recording or binaural sound Believe it or not, the groundwork was laid in the 1920s (no kidding, and some claim even earlier) when the idea of placing two microphones in a dummy head was first introduced as a source of loudspeaker stereo (which wouldn't go anywhere until Blumlein's contributions). It was the Germans who first produced a standard artificial listener for evaluating auditorium acoustics, and then played back the results over headphones -- the startling realism launched binaural recording. A binaural recording is made using two microphones placed in the ear canals of an anatomically accurate dummy head, such that all the normal spatial attributes of the human head are present (just as in real listening situations) when the recording is made. Designed to be played back through headphones, the results are nothing but astonishing. First time listeners to binaural recordings often swear someone is there with them, talking and walking around them, such is the realism accomplished.
binding post See connectors.
binky See Larry Blake's Film Sound Glossary.
birefringence Physics. The resolution or splitting of a light wave into two unequally reflected or transmitted waves by an optically anisotropic medium such as calcite or quartz. Also called double refraction. [AHD]
bit Abbr. b Abbreviation for binary unit or binary digit. 1. The smallest amount of digital information. A bit can store or represent only two states, 0 and 1. [The original term binary unit was coined by John Tukey of Bell Laboratories to represent the basic unit of information as defined by Shannon as a message representing one of two states.] 2. A little bit -- from Old English bita, meaning a piece bitten off.
bit clock The synchronizing signal that indicates the rate of individual data bits over a digital audio interface.
bit error rate or bit error ratio See BER.
bit rate The rate or frequency at which bits appear in a bit stream. Applied to digital audio, bit rate (kbits/sec/channel) equals the sampling rate (kHz) times the number of bits per sample. The data bit rate for a CD, for example, is 1.41M bits per second (44.1 kHz x 16 bits per sample x 2 channels). [The oft-quoted CD bit rate of 4.3218 MHz is for the raw bit rate which comes from multiplying 7,350 frames per second by 588, the number of channel bits.]
bits -- data converter See data converter bits.
bit stream A binary signal without regard to grouping.
bit-mapped display A display in which each pixel's color and intensity data are stored in a separate memory location.
Black, Harold S. (1898-1983) American electrical engineer and innovator most noted for his invention of negative feedback (U.S. patent 2,102,671).
black hole music Name given by astronomers to detecting the deepest note ever generated in the cosmos, a B-flat 57 octaves below middle C.
Blackmer, David (1927-2002). American scientist, inventor and businessman best known for founding dbx, Inc. and pioneering audio-grade VCAs for signal processing.
black noise See noise color.
black stick Clarinet. [Decharne]
blame shifter Shifts the pitch of mistakes down one octave so the audience thinks it was the bass player. [Thanks to DD at Sound Path Labs.]
blue moon For half a century, it's been known as the second full moon in the same calendar month; however, recently this definition was corrected by the editors of Sky & Telescope magazine. The correct definition, they say, is that a blue moon occurs when a season has four full moons, rather than the usual three. Further, they claim the misunderstanding is their fault based on an article they published in 1946. For all the wonderful details, see Once In A Blue Moon.
blue noise See noise color.
blue note Music. A flatted note, especially the third or seventh note of a scale, in place of an expected major interval. [From its use in blues music.] [AHD] Compare with brown note.
Bluetooth The code name given a wireless network protocol, after a 10th century Danish king, Harald Bluetooth, who unified Denmark. The code name was adopted in April, 1998, when Intel and Microsoft formed a consortium between themselves IBM, Toshiba, Nokia, Ericsson and Puma Technology. This protocol promised to bring wireless Internet to the masses, making the Web as ubiquitous as radio and TV. The Bluetooth SIG (special interest group), now numbering over 2000 companies, sees a world where equipment from different manufacturers works seamlessly together using Bluetooth as a sort of virtual cable. Check out the website to read the whole history of Harald Bluetooth and get all the details. Heavily challenged by Wi-Fi, which appears to have already accomplished what Bluetooth is still promising. Compare with ZigBee.
blue whales See SPL.
Blumlein, Alan Dower (1903-1942) English engineer who in a short working life span of 15 years wrote or cowrote 128 patents, developed stereophonic sound, designed new uses for microphones, designed a lateral disc-cutting system making modern records possible, developed much of the 405-line high definition television system broadcast in Britain until 1986, and improved radar systems such that they still operated 40 years later. Indeed, a genius by any definition, yet his story had to wait until 1999 to be told completely. Thanks to Robert Charles Alexander, former editor of AudioMedia magazine, a definitive biography now exists. Not only that, but Alexander has created a web site dedicated to Blumlein that eventually will have all 128 patents reproduced in their entirety, along with all of his binaural recordings (another of his inventions), downloadable as MP3 files, including binaural film clips (the world's first stereo films).
Blu-ray Disc A trademark of Sony for their optical disc video recording format developed for recording, rewriting and playback of HDTV, and is predicted to find its way into audio recording use.
BNC (bayonet Neill-Concelman) A miniature bayonet locking connector for coaxial cable. It was developed in the late '40s by a collaboration of Paul Neill and Carl Concelman based on a patent granted to the late Dr. Octavio M. Salati. In 1942, while at Bell Labs, Paul Neill developed what became known as the type N connector, named after him, which became a U.S. Navy standard. Carl Concelman, while at Amphenol, developed a bayonet version of the N connector, which became known as the type C connector, after him (the first true 50-ohm connector). Then, together, they developed a miniature bayonet locking version of the C connector and it was named the type BNC connector, after both of them. There is even an improved threaded version called the threaded Neill-Concelman or TNC connector. [Thanks to all who wrote me to help clarify this correct meaning. My condolences to all, who with passion, conviction, and great creativity, truly believe differently. It is a sad but true tale that BNC does NOT stand for "baby N connector," or "bayonet connector," or "bayonet Naval connector," or "British Naval Connector" (sorry Microsoft). For further verification search the web for info on Paul Neill and Carl Concelman.]
Bode, Hendrick Wade (1905-1982) American engineer who pioneered modern Control theory and Electronic Telecommunications.
Bode plot or Bode diagram A method developed by Hendrick Wade Bode to represent the gain and phase of a system as a function of frequency. Usually seen as a plot of log-gain and phase-angle values on a log-frequency scale. See Bode plots and contrast with Nyquist diagrams.
Bo Diddley (1928-2008) Stage name for the American rock legend. Born Otha Ellas Bates, his name was changed to Ellas B. McDaniel by his mother's first cousin, Gussie McDaniel, who raised him. In 1954, band member Billy Boy Arnold, a leading American blues harmonica player, came up with Bo Diddley as a stage name for McDaniel. He described it as a "bowlegged guy, a comical looking guy." Although another possibility is that there is a one-string guitar -- native to the Mississippi Delta where McDaniel was born, called a Diddley Bow, but it is said that Bo Diddley had never played one. [Thanks PT!]
bodhran Musical Instrument. A hand-held goatskin drum used in traditional Irish music and often played with a stick. [AHD]
Boner, C.P. (1900-1979) American physicist specializing in acoustics, considered the father of room equalization (U.S. patent 3,457,370).
boogaloo Nickname given to Abie "Boogaloo" Ames (1921-2002) in the 1940s for his boogie-woogie (see below) piano style.
boogie-woogie A style of blues piano playing characterized by an up-tempo rhythm, a repeated melodic pattern in the bass, and a series of improvised variations in the treble. [AHD]
Boole, George (1815-1864) British mathematician who devised a new form of algebra that represented logical expressions in a mathematical form now known as Boolean Algebra. [See Maxfield]
Boolean Algebra An algebra in which elements have one of two values and the algebraic operations defined on the set are logical OR, a type of addition, and logical AND, a type of multiplication. [AHD] (After George Boole.)
boost converter Switchmode Electronics. A type of step-up voltage converter, used in DC-DC conversion, favored by designers for its low cost and simplicity. Contrast with buck converter.
boost/cut equalizer The most common graphic equalizer. Available with 10 to 31 bands, on 1-octave to 1/3-octave spacing. The flat (0 dB) position locates all sliders at the center of the front panel. Comprised of bandpass filters, all controls start at their center 0 dB position and boost (amplify or make larger) signals by raising the sliders, or cut (attenuate or make smaller) the signal by lowering the sliders on a band-by-band basis. Commonly provide a center-detent feature identifying the 0 dB position. Proponents of boosting in permanent sound systems argue that cut-only use requires adding make-up gain that runs the same risk of reducing system headroom as boosting.
bop 1. A post-World War II style of jazz characterized by rhythmic and harmonic complexity, improvised solo performances, and a brilliant style of execution. [AHD] The word "bebop" was shortened to "bob" with Charlie Parker's 1947 recording "Bongo Bop." [Decharne] 2. "Playing bop is like playing Scrabble with all the vowels missing." Duke Ellington, Look August 10, 1954. [Crystal]
Boucherot, Paul (1869-1943) French engineer who studied the phenomena of electric conduction, introducing the concept of reactive power and inventing the synchronous electric motor in 1898. He also studied the thermal energy of the seas. The Claude-Boucherot Process described a scheme to power a turbo-alternator using warm seawater from tropical oceans to produce steam in a vacuum chamber. Theorem of Boucherot: In an AC electrical network, the total active power is the sum of the individual active powers, the total reactive power is the sum of the individual reactive powers, but the total apparent power is NOT equal to the sum of the individual apparent powers.
Boucherot cell After Paul Boucherot above; see Zobel network.
boundary microphone See PZM
bouzouki (also bazouki) Musical Instrument. A Greek stringed instrument having a long fretted neck and usually pear-shaped body. [AHD]
Bowditch curve See Lissajous figure.
Bozak, Rudy See Bozak.
BPL (broadband over power lines) General term for any of the "carrier-current" systems that conduct signals over existing electrical wiring or power lines.
BPM (beats per minute) Music. A measure of music tempo. See beat matching.
Bps (always uppercase B) Abbreviation for bytes per second.
bps (always lowercase b) Abbreviation for bits per second.
Braille, Louis (1809-1852) French musician, educator, and inventor of a writing and printing system for blind or visually impaired people (1829). He lost his sight at the age of three. [AHD] His braille system was first developed for blind musicians.
bray 1. To utter the loud, harsh cry of a donkey. 2. To sound loudly and harshly: The foghorn brayed all night. [AHD]
brewer See zymurgy.
brickwall filter Electronic Filters. A low-pass, high-pass or bandpass filter exhibiting extremely steep rolloff rates of greater than 50 dB/octave such that the response resembles a "brick wall."
bridge 1. In communications networks a bridge is a device that connects two or more different networks and forwards packets between them; specifically a device that (a) links or routes signals from one ring or bus to another, or from one network to another, (b) may extend the distance and capacity of a single LAN system, (c) performs no modification to packets or messages, (d) operates at the data-link layer of the OSI--Reference Model (Layer 2), (e) reads packets, and (f) passes only those with addresses on the same segment of the network as the originating user. 2. A functional unit that interconnects two local area networks that use the same logical link control (LLC) procedure, but may use different medium access control (MAC) procedures. 3. A balanced electrical network, e.g., a Wheatstone bridge. Contrast with hub.
bridged amplifier See BTL.
bridge-tied load See BTL.
briole Theater. Name for the adjustable wire ropes used for theater rigging, e.g., loudspeakers, lighting, scenery, etc.
broadband Also wideband, a transmission medium having a bandwidth greater than a traditional telephone (speech) channel (4 kHz). [Some argue that to be "broadband" the medium must support 20 kHz.] The most common broadband medium is coaxial cable carrying multiple audio, video and data channels simultaneously. Each channel takes up a different frequency on the cable. There will be guardbands, or empty spaces, between the channels to make sure each channel does not interfere with its neighbor. The most common example is the CATV cable. Contrast with baseband.
broadcasting Networks. A message sent out available for anyone to receive (just like radio broadcast), i.e., sending the same message to multiple recipients, as opposed to multicasting. Broadcasting sends a message to everyone on the network; multicasting sends a message to a specified few.
brown noise See noise color.
brown note Music. An urban myth that there existed a low frequency note that when played at high levels would make listeners loose bowel control. Exposed as false by Meyer Sound in a TV Myth Busters episode. Compare with blue note.
B&S gauge (Brown & Sharpe) See AWG.
BSI (British Standards Institute) The National Standards organization responsible for coordinating standards preparation for sound equipment in the UK.
B-taper See potentiometer.
BTL (bridge-tied load) Amplifiers. An amplifier configuration where the loudspeaker load is connected between the two hot outputs of two amplifiers operating in bridged amplifier mode, i.e., anti-phase, where the output of one amplifier drives the the second amplifier out of phase, or inverted, and operates at unity gain. Thus the second amplifier (usually the second channel of a two channel design) acts as a current amplifier (with inverting voltage). This doubles the output voltage (one-half from the first amplifier and one-half from the second amplifier) and theoretically produces four times the power output (double the voltage equals double the current equals four times the power). However this virtually never happens in practice since the amplifier power supply runs out of current long before four times the power is reached. Typically, amplifiers operating in bridged amplifier mode deliver twice their single-ended output power. Semiconductor audio power amplifiers use BTL configurations as a way to maximize power output from the small voltage sources found in internet appliances and automotive applications.
BTU (British thermal unit) 1. The quantity of heat required to raise the temperature of one pound of water from 60° to 61°F at a constant pressure of one atmosphere. 2. The quantity of heat equal to 1/180 of the heat required to raise the temperature of one pound of water from 32° to 212°F at a constant pressure of one atmosphere. [AHD] The Btu is equivalent to 0.252 kilogram-calorie or 1055 joules. And 1 watt equals 3.41 BTUs/hour.
buck converter Switchmode Electronics. A type of step-down voltage converter, used in DC-DC conversion, favored by designers for its low cost and simplicity. Contrast with boost converter.
buds See: personal monitors
buffer In data transmission, a temporary storage location for information being sent or received.
buffer amplifier The IEEE dictionary defines buffer amplifier as "An amplifier in which the reaction of output-load-impedance variation on the input circuit is reduced to a minimum for isolation purposes." This is a bit confusing, but one thing is clear, it says that at the most fundamental level a buffer amplifier isolates (or buffers) the loading effects (impedance) of two stages. It separates them, making them independent. In analog designs, buffer amplifiers are used for just this purpose. If the next circuit stage in a design has impedance characteristics that are detrimental to the preceding stage then a buffer amplifier minimizes this interaction. And its use is not confined to analog design, digital circuits use buffers to minimize similar loading effects.
The term "amplifier" comes about from the fact that most buffer amplifiers also provide either voltage or current gain. In this sense, a normal audio power amplifier can be called a buffer amplifier - it buffers your preamp from your very low impedance loudspeakers. [Historical Note: Sometimes a buffer amplifier provides speed as well as isolation. In the mid '70s, National Semiconductor offered in their specialty hybrid circuits line, a product simply named "Fast Buffer," whose purpose was to provide impedance isolation, but could do so at high megawiggle speeds (not a trivial task back then), and if that wasn't good enough, they also offered a "Damn Fast Buffer," that could really get the job done (true story).] As can be seen, the term buffer amplifier is a bit vague: it provides isolation, that much is sure, however, it may also offer voltage gain, current gain, or both. And it may even provide an unbalanced-to-balanced function, or vice-versa.
bug A surprisingly old word used most often to connote a problem with a program or computer. From the 1896 edition of Hawkin's New Catechism of Electricity (Theo. Audel & Co.) comes this definition: "The term `bug' is used to a limited extent to designate any fault or trouble in the connections or working of electric apparatus." To get rid of see Agans.
Bulwer-Lytton Fiction Contest A whimsical literary competition that challenges entrants to compose the opening sentence to the worst of all possible novels. Created by Professor Scott Rice, English Department, at San Jose State University in 1982, the contest is still sponsored by the college. The name comes from Edward George Earle Bulwer-Lytton, who wrote the famous line "It was a dark and stormy night ..." as the opening words in his novel Paul Clifford (1830). Check it out -- great fun.
When Wilkie Collins's detective novel The Woman in White appeared in 1860, it created a considerable stir. A feature much remarked upon was the villain, Count Fosco. One lady reader, however, was not so impressed and wrote to tell Collins, "You really do not know a villain. Your Count Fosco is a very poor one." She then offered to supply Collins with a villain next time he wanted one. "Don't think that I am drawing upon my imagination. The man is alive and constantly under my gaze. In fact, he is my husband." The writer was Bulwer-Lytton's wife. [Bartlett's Book of Anecdotes]
bumbershoot 1. An umbrella. Derived from an alteration of umbrella + alteration of (para)chute. [AHD] 2. A Seattle arts festival held each Labor Day weekend, featuring over 2,500 artists including comedians, dancers, painters, poets, sculptors, tightrope walkers, acrobats, filmmakers, bookbinders, DJs, thespians, and musicians of every genre -- from classical to hip-hop.
Bundle The shortened form for CobraNet® Bundle; always with a capital B to differentiate it from a bundle of wires.
burnt-in time code See time code.
burst error A large number of data bits lost on the medium because of excessive damage to or obstruction on the medium.
burst noise See popcorn noise.
bus One or more electrical conductors used for transmitting signals or power from one or more sources to one or more destinations. Often used to distinguish between a single computer system (connected together by a bus) and multi-computer systems connected together by a network.
buss To kiss. [AHD]
Butterworth filter A type of electronic filter characterized by having a maximally flat magnitude response, i.e., no amplitude ripple in the passband. [Contrast with Chebyshev] This circuit is based upon Butterworth functions (or Butterworth polynomials). [For the mathematically inclined, these polynomials represent a specialized solution to a general MacLaurin series based upon a Taylor series expansion. Named after Stephen Butterworth, a British engineer who first described this response in his paper "On the Theory of Filter Amplifiers," Wireless Engineer, vol. 7, 1930, pp. 536-541. Eleven years later, V.D. Landon coined the phrase maximally flat in his paper "Cascade Amplifiers with Maximal Flatness," RCA Review, vol. 5, 1941, pp. 347-362.]
Butterworth crossover The category of loudspeaker crossover design (or alignment) based on Butterworth filters (see above).
buzznack An old organ, out of order and playing badly. [Kacirk]
byte Abbr. B A group of eight bits (a word) operating together. Usually abbreviated in uppercase to distinguish "byte" from "bit" which uses lowercase "b". See Bps.
