Seastones is an album by American composer and musician Ned Lagin .
85-406: In 1975 Lagin released the quadraphonic album of electronic music , (composed between 1970 and 1974), a small part of the complete Seastones composition, on Round Records and then United Artists Records . A new, two-CD album of Seastones was released on March 8, 2018. Lagin composed Seastones over the course of five years. It was recorded and mixed in just as many studios, and mastered at
170-429: A root mean square (RMS) value. For example, 1 Pa RMS sound pressure (94 dBSPL) in atmospheric air implies that the actual pressure in the sound wave oscillates between (1 atm − 2 {\displaystyle -{\sqrt {2}}} Pa) and (1 atm + 2 {\displaystyle +{\sqrt {2}}} Pa), that is between 101323.6 and 101326.4 Pa. As the human ear can detect sounds with
255-682: A transmission medium such as a gas, liquid or solid. In human physiology and psychology , sound is the reception of such waves and their perception by the brain . Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound . Different animal species have varying hearing ranges . Sound
340-648: A given area as modified by the environment and understood by people, in context of the surrounding environment. There are, historically, six experimentally separable ways in which sound waves are analysed. They are: pitch , duration , loudness , timbre , sonic texture and spatial location . Some of these terms have a standardised definition (for instance in the ANSI Acoustical Terminology ANSI/ASA S1.1-2013 ). More recent approaches have also considered temporal envelope and temporal fine structure as perceptually relevant analyses. Pitch
425-434: A high speed arithmetic logic unit and magnetic core memory; an Intel 8080 microprocessor system built by Lagin; and at the beginning of 1975 an Altair 8800 . The computer-controlled systems was designed and built for group live performance, with the performers' instruments and voices routed through analog and digital synthesis and processing hardware. Seastones was one of the first commercially released recordings to feature
510-405: A medium such as air, water and solids as longitudinal waves and also as a transverse wave in solids . The sound waves are generated by a sound source, such as the vibrating diaphragm of a stereo speaker. The sound source creates vibrations in the surrounding medium. As the source continues to vibrate the medium, the vibrations propagate away from the source at the speed of sound , thus forming
595-488: A particular pitch is determined by pre-conscious examination of vibrations, including their frequencies and the balance between them. Specific attention is given to recognising potential harmonics. Every sound is placed on a pitch continuum from low to high. For example: white noise (random noise spread evenly across all frequencies) sounds higher in pitch than pink noise (random noise spread evenly across octaves) as white noise has more high frequency content. Duration
680-428: A sixth. Much of the album consists of electronically processed traditional instruments and voice, and a cadre of synthesizers (a custom E-mu Modular Synthesizer controlled by and processed through then-cutting-edge computer technology, with software patches and compositions by Lagin; an ARP 2500 and ARP 2600; and a Buchla Modular System). The early computers employed by Lagin included an Interdata 7/16 computer with
765-528: A specialized demodulator to decode four fully independent sound channels. This allowed for full channel separation. Such systems could be prone to reduced record life. However, more durable vinyl formulations were quickly developed to work around this problem and nearly all discrete LPs use special vinyl. When discrete quadraphonic LPs are played on conventional stereo record players the entire music program can be heard in stereo. The third major format for four-channel vinyl LPs, known as CD-4 or Quadradisc ,
850-417: A two-channel transmission medium (usually an LP record) before being decoded to four channels and presented to four speakers. To transmit four individual audio signals in a stereo-compatible manner, there must be four simultaneous linear equations to reproduce the original four audio signals at the output. These systems used matrix decoding technology to recover four channels from the two channels recorded on
935-466: A wide range of amplitudes, sound pressure is often measured as a level on a logarithmic decibel scale. The sound pressure level (SPL) or L p is defined as Since the human ear does not have a flat spectral response , sound pressures are often frequency weighted so that the measured level matches perceived levels more closely. The International Electrotechnical Commission (IEC) has defined several weighting schemes. A-weighting attempts to match
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#17328757414761020-510: A ⋂ horseshoe topology. However, all these came too late in the game and were too expensive or difficult to procure for public purchase, to rescue matrix quad from obscurity. By the early 2000s more sophisticated "discrete" multichannel systems had mostly replaced matrix technologies, providing a higher level of performance and full channel independence. Today, software can be used to take the place of hardware decoding. Modern software algorithms are capable of more accurate decoding performance than
1105-488: Is also known as the Newton–Laplace equation. In this equation, K is the elastic bulk modulus, c is the velocity of sound, and ρ {\displaystyle \rho } is the density. Thus, the speed of sound is proportional to the square root of the ratio of the bulk modulus of the medium to its density. Those physical properties and the speed of sound change with ambient conditions. For example,
1190-399: Is an undesirable component that obscures a wanted signal. However, in sound perception it can often be used to identify the source of a sound and is an important component of timbre perception (see below). Soundscape is the component of the acoustic environment that can be perceived by humans. The acoustic environment is the combination of all sounds (whether audible to humans or not) within
1275-478: Is characterized by) its unique sounds. Many species, such as frogs, birds, marine and terrestrial mammals , have also developed special organs to produce sound. In some species, these produce song and speech . Furthermore, humans have developed culture and technology (such as music, telephone and radio) that allows them to generate, record, transmit, and broadcast sound. Noise is a term often used to refer to an unwanted sound. In science and engineering, noise
1360-424: Is commonly used for diagnostics and treatment. Infrasound is sound waves with frequencies lower than 20 Hz. Although sounds of such low frequency are too low for humans to hear as a pitch, these sound are heard as discrete pulses (like the 'popping' sound of an idling motorcycle). Whales, elephants and other animals can detect infrasound and use it to communicate. It can be used to detect volcanic eruptions and
1445-445: Is defined as "(a) Oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation. (b) Auditory sensation evoked by the oscillation described in (a)." Sound can be viewed as a wave motion in air or other elastic media. In this case, sound is a stimulus. Sound can also be viewed as an excitation of
1530-399: Is different than for stereo versions of the same recording. Most studio equipment is designed for stereo only, so specialized multichannel mixing consoles and playback systems must be available. For classical music, producers have typically preferred an effect where the orchestra appears in stereo in only the front channels, and the natural reverberation or "echo" of the concert hall is in all
1615-552: Is electronic music of the best kind — a shifting sonic landscape out of which the strangest things may emerge." Quadraphonic sound Quadraphonic (or quadrophonic and sometimes quadrasonic ) sound – equivalent to what is now called 4.0 surround sound – uses four audio channels in which speakers are positioned at the four corners of a listening space. The system allows for the reproduction of sound signals that are (wholly or in part) independent of one another. Four channel quadraphonic surround sound can be used to recreate
1700-450: Is half of the full speed. The slower speed results in significantly poorer sound quality. RCA Records followed, in April 1970, with its announcement of a four-channel version of the 8-track tape , named Quad-8 or Quadraphonic 8-track tape (later shortened to just Q8 ). These eventually appeared in staggered releases (70 Tapes) split by October, November, and December 1970. The format
1785-418: Is heard; specif.: a. Psychophysics. Sensation due to stimulation of the auditory nerves and auditory centers of the brain, usually by vibrations transmitted in a material medium, commonly air, affecting the organ of hearing. b. Physics. Vibrational energy which occasions such a sensation. Sound is propagated by progressive longitudinal vibratory disturbances (sound waves)." This means that the correct response to
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#17328757414761870-465: Is perceived as how "long" or "short" a sound is and relates to onset and offset signals created by nerve responses to sounds. The duration of a sound usually lasts from the time the sound is first noticed until the sound is identified as having changed or ceased. Sometimes this is not directly related to the physical duration of a sound. For example; in a noisy environment, gapped sounds (sounds that stop and start) can sound as if they are continuous because
1955-457: Is perceived as how "low" or "high" a sound is and represents the cyclic, repetitive nature of the vibrations that make up sound. For simple sounds, pitch relates to the frequency of the slowest vibration in the sound (called the fundamental harmonic). In the case of complex sounds, pitch perception can vary. Sometimes individuals identify different pitches for the same sound, based on their personal experience of particular sound patterns. Selection of
2040-422: Is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz. In air at standard temperature and pressure , the corresponding wavelengths of sound waves range from 17 m (56 ft) to 17 mm (0.67 in). Sometimes speed and direction are combined as a velocity vector ; wave number and direction are combined as a wave vector . Transverse waves , also known as shear waves, have
2125-711: Is to say, the four channels produced at the final stage were not truly identical to those with which the process had begun. In order for the effect to work as intended a recording engineer needed to be specially trained for working in each of these formats. Special mixing rules for matrix recording minimize the technological limitations inherent in matrix formats and mask or eliminate undesired side effects. The first of these were basic systems with relatively poor performance developed by Electro-Voice ( EV-4/Stereo-4 ) and Dynaco ( Dynaquad (DY) ). A so-called matrix format, it utilized four sound channels which were "encoded" into two stereo album tracks. These were then "decoded" into
2210-512: The Jefferson Airplane Grace Slick (processed voice), Spencer Dryden (processed percussion), and David Freiberg (processed voice) also appear on the album. Seastones was re-released in stereo on CD by Rykodisc in 1990. The CD version includes the original Round Records nine-section Seastones (42:34) from February 1975, and a previously unreleased, six-section version (31:05) from December 1975. Both are partial versions of
2295-509: The SQ system was greatly improved by the introduction of SQ Full Logic decoding in 1975 using the Motorola chips MC1312, MC1314 & MC1315. Both SQ and QS had significant support from major record companies and hardware manufacturers during the 1970s. They also achieved notable sales and market penetration. Unfortunately, due to the similarities in name and technology these could easily be confused by
2380-401: The equilibrium pressure, causing local regions of compression and rarefaction , while transverse waves (in solids) are waves of alternating shear stress at right angle to the direction of propagation. Sound waves may be viewed using parabolic mirrors and objects that produce sound. The energy carried by an oscillating sound wave converts back and forth between the potential energy of
2465-483: The hearing range for humans or sometimes it relates to a particular animal. Other species have different ranges of hearing. For example, dogs can perceive vibrations higher than 20 kHz. As a signal perceived by one of the major senses , sound is used by many species for detecting danger , navigation , predation , and communication. Earth's atmosphere , water , and virtually any physical phenomenon , such as fire, rain, wind, surf , or earthquake, produces (and
2550-461: The 1970s have been reissued in modern surround sound systems such as Super Audio CD , DTS , Dolby Digital , DVD-Audio and Blu-ray . Multichannel home audio reproduction has experienced a revival since 2000 and new four channel recordings have also been released to the public since this time. A quadraphonic system will reproduce right front, right rear, left front, and left rear audio signals in four separate speakers. The reproduction capability of
2635-515: The 1970s this station broadcast a signal which could be tuned as two separate stations with conventional stereo receivers. San Francisco classical music station KKHI-FM broadcast the San Francisco Opera in "compatible" (that is, matrix-encoded) quadraphonic format during the 1970s, as did Chicago station WFMT 's live "Chicago Lyric Opera" broadcasts. KRMH -FM ("Good Karma Radio")(San Marcos/Austin, Texas) broadcast in "Quad Stereo" in
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2720-439: The 1970s used "matrix" technologies to encode and decode four channels of audio information in a 2-channel medium, usually an LP. The poor decoding performance of early matrix formats was the main reason they disappeared once improved matrix systems arrived. The later matrix systems were based on work by Peter Scheiber . His basic formula used 90° phase-shift circuitry to enable enhanced 4–2–4 matrix systems to be developed, of which
2805-404: The 1970s, particularly among car audio enthusiasts. In the 1970s specialized hardware systems were marketed by major electronic manufacturers to the public for decoding 4-channel recordings. These decoders were often sold as separate electronic components. Decoders were also available as built in features of some audio receivers or amplifiers sold during the 1970s. Many quadraphonic recordings in
2890-837: The Grateful Dead at 23 Grateful Dead concerts between June 23, 1974, in Miami, and October 20, 1974, in San Francisco. These took place typically between the first and second sets of the regular Grateful Dead shows. At some concerts, Seastones would form an entire set, and at other shows it would segue into Grateful Dead songs such as "Playing in the Band" or "Dark Star". There were five live performances of Seastones that occurred outside of Grateful Dead shows: November 28, 1973, June 6, 1975, September 19, 1975, November 15, 1975, and November 22, 1975. On Allmusic , Steven McDonald said, "In short, Seastones
2975-552: The United States. Such machines appeared in some European electronic-music studios by 1954. Early attempts to reproduce four channel sound for home playback began with audio laboratory engineers in the late 1960s. Producer Thomas Mowrey, initially working at the Eastman School of Music , was one of the pioneers of classical quadraphonic recording. He later made quadraphonic productions for Deutsche Grammophon and other labels in
3060-404: The additional property, polarization , which is not a characteristic of longitudinal sound waves. The speed of sound depends on the medium the waves pass through, and is a fundamental property of the material. The first significant effort towards measurement of the speed of sound was made by Isaac Newton . He believed the speed of sound in a particular substance was equal to the square root of
3145-461: The audible range and uses the difference channels to separate rear audio information from the main channels. Because the CD-4 system maintains four independent signals throughout the process it can accurately reconstruct the intended four channel sound field. UD-4/UMX was developed by Nippon/Columbia ( Denon ). This is a hybrid discrete/matrix system. Only 35 to 40 items are encoded in this format and it
3230-512: The basis of all sound waves. They can be used to describe, in absolute terms, every sound we hear. In order to understand the sound more fully, a complex wave such as the one shown in a blue background on the right of this text, is usually separated into its component parts, which are a combination of various sound wave frequencies (and noise). Sound waves are often simplified to a description in terms of sinusoidal plane waves , which are characterized by these generic properties: Sound that
3315-595: The channels at a time. The last release in the quadraphonic 8-track format was in 1978, although most had stopped appearing by the end of 1976. There were some experiments done with radio broadcasts (e.g., a Cliff Richard concert by the BBC , whose earliest quadraphonic broadcast was in July 1974 ), but they were short-lived. One of the longest-lived radio broadcasts was WQSR -FM "Quad 102½" in Sarasota, Florida . Throughout most of
3400-411: The duration of theta wave cycles. This means that at short durations, a very short sound can sound softer than a longer sound even though they are presented at the same intensity level. Past around 200 ms this is no longer the case and the duration of the sound no longer affects the apparent loudness of the sound. Timbre is perceived as the quality of different sounds (e.g. the thud of a fallen rock,
3485-520: The earlier hardware technologies. All of the multichannel audio systems in common use today are digital systems. Digital multichannel audio has been available for the home since the introduction of surround sound movies in the 1990s using Dolby Digital and DTS. The most common digital media capable of reproducing surround sound music today are Super Audio CD, DVD, and Blu-ray, all of which are capable of playing high-resolution audio with multiple channels. The audio mixing process for four channel sound
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3570-477: The early 1970s from its studios and transmitter near Buda, Texas . WWWW-FM (W4-QUAD 106.7) (Detroit) broadcast QS encoded quadraphonic sound in 1974. KEXL -FM ("KEXL 104.5") (San Antonio, Texas) broadcast in "Quadraphonic" in the early to mid 1970s from its studios in a high-rise office building off Main Plaza. Sound In physics , sound is a vibration that propagates as an acoustic wave through
3655-507: The early 1970s, but many of these were released only as stereo recordings. A small number of quadraphonic recordings were introduced to the American consumer market by Vanguard Records in June 1969 on reel-to-reel tape. The most popular medium used to market recordings to the public during the 1970s was the vinyl LP phonograph record . Quadraphonic recordings on 8-track tape were also popular in
3740-401: The equation c = γ ⋅ p / ρ {\displaystyle c={\sqrt {\gamma \cdot p/\rho }}} . Since K = γ ⋅ p {\displaystyle K=\gamma \cdot p} , the final equation came up to be c = K / ρ {\displaystyle c={\sqrt {K/\rho }}} , which
3825-439: The extra compression (in case of longitudinal waves) or lateral displacement strain (in case of transverse waves) of the matter, and the kinetic energy of the displacement velocity of particles of the medium. Although there are many complexities relating to the transmission of sounds, at the point of reception (i.e. the ears), sound is readily dividable into two simple elements: pressure and time. These fundamental elements form
3910-406: The fastest in solid atomic hydrogen at about 36,000 m/s (129,600 km/h; 80,530 mph). Sound pressure is the difference, in a given medium, between average local pressure and the pressure in the sound wave. A square of this difference (i.e., a square of the deviation from the equilibrium pressure) is usually averaged over time and/or space, and a square root of this average provides
3995-504: The full composition, which has not been released. Other unreleased Lagin Seastones -related compositions from the same period include L and Make a Cat Laugh . A new, two CD album of Seastones was released on March 8, 2018. This album, not a re-issue, presents most but not all of the composition as originally composed but never released or heard before. For this release, Seastones was re-mixed and re-mastered in stereo. It includes most of
4080-481: The hearing mechanism that results in the perception of sound. In this case, sound is a sensation . Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration , sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an acoustician , while someone working in the field of acoustical engineering may be called an acoustical engineer . An audio engineer , on
4165-430: The highly realistic effect of a three-dimensional live concert hall experience in the home. It can also be used to enhance the listener experience beyond the directional limitations of ordinary two channel stereo sound. Quadraphonic audio was the earliest consumer product in surround sound. Since it was introduced to the public in the early 1970s many thousands of quadraphonic recordings have been made. Quadraphonic sound
4250-426: The information for timbre identification. Even though a small section of the wave form from each instrument looks very similar, differences in changes over time between the clarinet and the piano are evident in both loudness and harmonic content. Less noticeable are the different noises heard, such as air hisses for the clarinet and hammer strikes for the piano. Sonic texture relates to the number of sound sources and
4335-440: The interaction between them. The word texture , in this context, relates to the cognitive separation of auditory objects. In music, texture is often referred to as the difference between unison , polyphony and homophony , but it can also relate (for example) to a busy cafe; a sound which might be referred to as cacophony . Spatial location represents the cognitive placement of a sound in an environmental context; including
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#17328757414764420-436: The listener. Quadraphonic audio reproduction on vinyl phonograph records was problematic. As technologies advanced rapidly during the 1970s several different solutions were proposed to reproduce four channel sound from LPs. Some of these systems were much more successful than others. The simplest systems were "derived" (2–2–4) formats. These were soon followed by much more sophisticated "matrix" (4–2–4) formats, and finally, by
4505-410: The main channels. The difference signals are encoded in ultrasonic carrier frequencies in the range of 30 kHz, which is above the audible range. CD-4 requires a specialized phono cartridge with a "Shibata" stylus to read these additional high frequencies. The combined signals are then sent to a special demodulator for four channel decoding. The demodulator converts the ultrasonic signals back into
4590-445: The most advanced "discrete" (4–4–4) formats. Derived (2–2–4) formats are simple and inexpensive electronic solutions that add or extract rear "ambience" or "reverberation" sound channels from stereo records i.e., studio reverb, audience applause, etc. There is no precise placement of individual instruments in the rear channels. With matrix formats four channels are converted (encoded) down to two channels. These are then passed through
4675-461: The offset messages are missed owing to disruptions from noises in the same general bandwidth. This can be of great benefit in understanding distorted messages such as radio signals that suffer from interference, as (owing to this effect) the message is heard as if it was continuous. Loudness is perceived as how "loud" or "soft" a sound is and relates to the totalled number of auditory nerve stimulations over short cyclic time periods, most likely over
4760-483: The original 1970–1974 studio forms, those parts of Lagin's concurrent but unfinished composition L that are shared with Seastones , as well as some of the moment forms generated and incorporated into the composition from live performances that took place from 1973 to 1975. This two CD album contains 83 tracks (54 tracks on CD One and 29 tracks on CD Two) and altogether is 111 minutes long. Ned Lagin performed versions of Seastones with Phil Lesh and with other members of
4845-401: The original four sound channels. But with poor decode performance, these systems failed to match the accuracy or channel independence of later matrix formats. The original systems (DY and EV-4) suffered from low front left-right separation (around 12 dB) and a poor rear left-right separation of 2 dB. The decoders were designed more to give an effect rather than accurate decoding, which
4930-558: The original four sound channels. The QS system debuted in the United States in March 1971 and was improved by their Vario-Matrix system in 1973. The second, SQ , was developed and marketed by Columbia Records and Sony and entered the US market in April 1971. The SQ format was also used by companies such as EMI in Great Britain, who pressed several SQ album releases. The sound separation of
5015-482: The other hand, is concerned with the recording, manipulation, mixing, and reproduction of sound. Applications of acoustics are found in almost all aspects of modern society, subdisciplines include aeroacoustics , audio signal processing , architectural acoustics , bioacoustics , electro-acoustics, environmental noise , musical acoustics , noise control , psychoacoustics , speech , ultrasound , underwater acoustics , and vibration . Sound can propagate through
5100-580: The placement of a sound on both the horizontal and vertical plane, the distance from the sound source and the characteristics of the sonic environment. In a thick texture, it is possible to identify multiple sound sources using a combination of spatial location and timbre identification. Ultrasound is sound waves with frequencies higher than 20,000 Hz. Ultrasound is not different from audible sound in its physical properties, but cannot be heard by humans. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Medical ultrasound
5185-558: The pressure acting on it divided by its density: This was later proven wrong and the French mathematician Laplace corrected the formula by deducing that the phenomenon of sound travelling is not isothermal, as believed by Newton, but adiabatic . He added another factor to the equation— gamma —and multiplied γ {\displaystyle {\sqrt {\gamma }}} by p / ρ {\displaystyle {\sqrt {p/\rho }}} , thus coming up with
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#17328757414765270-423: The production of harmonics and mixed tones not present in the original sound (see parametric array ). If relativistic effects are important, the speed of sound is calculated from the relativistic Euler equations . In fresh water the speed of sound is approximately 1,482 m/s (5,335 km/h; 3,315 mph). In steel, the speed of sound is about 5,960 m/s (21,460 km/h; 13,330 mph). Sound moves
5355-415: The public. Discrete reproduction describes a quadraphonic system in which all four channels are fully independent of each other. As its name suggests, with discrete formats the original four audio channels are passed through a four-channel transmission medium and presented to a four-channel reproduction system and fed to four speakers. This is defined as a 4–4–4 system. Discrete phonograph systems use
5440-555: The question: " if a tree falls in a forest and no one is around to hear it, does it make a sound? " is "yes", and "no", dependent on whether being answered using the physical, or the psychophysical definition, respectively. The physical reception of sound in any hearing organism is limited to a range of frequencies. Humans normally hear sound frequencies between approximately 20 Hz and 20,000 Hz (20 kHz ), The upper limit decreases with age. Sometimes sound refers to only those vibrations with frequencies that are within
5525-516: The rear channels that are of equal importance to the front channels. It can expand on the listener's sense of direction and spaciousness in a way similar to what happened when recording engineers introduced stereo recording. In some four channel recordings sounds move in full rotation around the listener. Mixing engineers can also aim for a hybrid effect between styles. While quadraphonic effects have sometimes been considered artificial, musical enjoyment can be dramatically enhanced by more fully involving
5610-450: The rear speakers should be of the same quality or almost the same quality as the front speakers; ideally, a quadraphonic system uses four identical speakers. The first machines used for 4-channel sound recording were analog reel-to-reel tape recorders. These were developed for use by audio engineers in professional studios during the 1950s in Germany by Telefunken and also by Ampex in
5695-411: The record. Matrix systems can have a significant level of channel independence but not full channel separation. Matrix quadraphonic recordings can be played in two channels on conventional stereo record players. There are varying levels of stereo and mono compatibility in these systems. The term compatible indicates that: This 4:2:4 process could not be accomplished without some information loss. That
5780-443: The response of the human ear to noise and A-weighted sound pressure levels are labeled dBA. C-weighting is used to measure peak levels. A distinct use of the term sound from its use in physics is that in physiology and psychology, where the term refers to the subject of perception by the brain. The field of psychoacoustics is dedicated to such studies. Webster's dictionary defined sound as: "1. The sensation of hearing, that which
5865-528: The sound is called the medium . Sound cannot travel through a vacuum . Studies has shown that sound waves are able to carry a tiny amount of mass and is surrounded by a weak gravitational field. Sound is transmitted through gases, plasma, and liquids as longitudinal waves , also called compression waves. It requires a medium to propagate. Through solids, however, it can be transmitted as both longitudinal waves and transverse waves . Longitudinal sound waves are waves of alternating pressure deviations from
5950-420: The sound wave. At a fixed distance from the source, the pressure , velocity , and displacement of the medium vary in time. At an instant in time, the pressure, velocity, and displacement vary in space. The particles of the medium do not travel with the sound wave. This is intuitively obvious for a solid, and the same is true for liquids and gases (that is, the vibrations of particles in the gas or liquid transport
6035-513: The speakers. Some live concert recordings of popular music have also been mixed this way. Classical recordings rarely place primary or solo instruments in the rear channels, though it is done occasionally. A few classical recordings have been made from a perspective in which the listener seems to be seated in the middle of the orchestra. One example is the 1973 Columbia Masterworks recording of Béla Bartók 's Concerto for Orchestra , conducted by Pierre Boulez . The original four channel recording
6120-417: The speed of sound in gases depends on temperature. In 20 °C (68 °F) air at sea level, the speed of sound is approximately 343 m/s (1,230 km/h; 767 mph) using the formula v [m/s] = 331 + 0.6 T [°C] . The speed of sound is also slightly sensitive, being subject to a second-order anharmonic effect, to the sound amplitude, which means there are non-linear propagation effects, such as
6205-407: The tape running in the same direction. Pre-recorded four channel reel-to-reel tapes were recorded at 7 1 ⁄ 2 inches per second (IPS), which is the fastest speed used for consumer grade reel-to-reel machines. By comparison stereo pre-recorded reel-to-reel tapes have 2 different programs with each running the opposite direction. Many stereo tapes were recorded at only 3 3 ⁄ 4 IPS, which
6290-413: The two main leaders were Columbia 's SQ and Sansui 's QS systems. The three most popular quadraphonic LP formats in the 1970s were SQ (Stereo Quadraphonic) , QS (Regular Matrix) and CD-4 (Compatible Discrete 4) / Quadradisc . The Japanese governing body and audio hardware manufacturers defined standards for quadraphonic sound. RM ( Regular Matrix ) was used a synonym for QS, QM ( Quadraphonic Matrix
6375-669: The use of digital computers, and Lagin was the first to perform on stage live with computers. It was also a very early instance of multiple musicians' audio and control signals being interconnected before MIDI. The album was mixed in quadraphonic sound, released in quad-encoded stereo , and featured guest performances by members of the Grateful Dead , including Jerry Garcia playing processed electric and pedal steel guitars, and voice; Phil Lesh playing electronic Alembic bass; and Mickey Hart on processed percussion. David Crosby (processed voice and electric 12-string guitar), and members of
6460-566: The vibrations, while the average position of the particles over time does not change). During propagation, waves can be reflected , refracted , or attenuated by the medium. The behavior of sound propagation is generally affected by three things: When sound is moving through a medium that does not have constant physical properties, it may be refracted (either dispersed or focused). The mechanical vibrations that can be interpreted as sound can travel through all forms of matter : gases, liquids, solids, and plasmas . The matter that supports
6545-430: The whir of a drill, the tone of a musical instrument or the quality of a voice) and represents the pre-conscious allocation of a sonic identity to a sound (e.g. "it's an oboe!"). This identity is based on information gained from frequency transients, noisiness, unsteadiness, perceived pitch and the spread and intensity of overtones in the sound over an extended time frame. The way a sound changes over time provides most of
6630-589: Was a commercial failure when first introduced due to a variety of technical issues and format incompatibilities. Four channel audio formats can be more expensive to produce than standard two-channel stereo. Playback requires additional speakers and amplifier channels. It may also require specially designed decoding equipment. The introduction of home cinema products in the 1990s were first intended for movie sound, but also brought multi-channel music reproduction into popularity again. By this time new digitally based formats had been created. Many four channel recordings from
6715-485: Was almost identical in appearance to stereo 8-tracks, except for a small sensing notch in the upper left corner of the cartridge. This signaled a quadraphonic 8-track player to combine the odd tracks as audio channels for program 1, and the even tracks as channels for program 2. The format was not backward-compatible with stereo or mono players; although quadraphonic players would play stereo 8-tracks, playing quadraphonic tapes on stereo players resulted in hearing only one-half
6800-637: Was devised by the Japanese JVC Corporation along with its US counterpart RCA Records . This quadraphonic format was first marketed in the United States in May 1972. A fully discrete system, it eschewed matrix technologies in favor of a method similar to the encoding of stereo FM broadcasts. With stereo records, the system uses 2 main left and right audio channels, and this is what allows CD-4 to maintain compatibility with conventional stereo playback. CD-4 also adds 2 additional "difference" audio channels to
6885-458: Was intended by the producer or recording engineer. Improved systems based on Peter Scheiber 's work on utilizing 90-degree phase-shift circuitry came later, namely the QS and SQ systems. The first of these, known as QS , was developed by Sansui Electric . A so-called matrix format, it utilized four sound channels, which were "encoded" into two stereo album tracks. These were then "decoded" into
6970-454: Was mainly due to limitations in both systems. Since both systems were very closely related mathematically, users only needed one decoder of either system to playback albums of both systems. The differences between the early and late matrix systems were so vast, it made decoding DY/EV-4 with either SQ or QS decoders with accuracy impossible; the results often being a "smeared" or poorly defined sound stage, which could be vastly different from what
7055-809: Was marketed only in the UK, Europe, and Japan. The short-lived system suffered from incompatibility with regular stereo playback due to phase differences between the left and right channels. UD-4 was less critical in its setup than CD-4 because the carriers did not have to handle frequencies as high as those found in the CD-4 system. Quadraphonic systems based on tape were also introduced, based on new equipment capable of playing four discrete channels. These recordings are all discrete 4–4–4 recordings released in reel-to-reel and 8-track cartridge formats. Specially designed four channel machines were required to play these recordings. They are not compatible with stereo players. In these systems all four available tracks were recorded on
7140-486: Was released on matrix LP and 8-track tape, and reissued on the Super Audio CD format by Dutton Vocalion in 2018. Notes supplied with the recording indicate the direction from which each group of instruments can be heard. Pop, rock and jazz music producers have tended to employ a mixing style with a relatively high degree of musical separation between the four channels. This type of recording may place musical sounds in
7225-688: Was used for Stereo-4 and Dynaquad ) and QX ( QuadXtra , based on D.H. Cooper "Dual-Triphonic") for UD4 . With Scheiber and Martin Willcocks, Jim Fosgate developed the Tate II 101 SQ decoder, which produced a very accurate sound field by using gain riding and the Haas effect to mask decoding artifacts. It used custom, hand-assembled and ‑calibrated circuitry with components sorted to 1%, for exact performance. Sansui's QSD-series decoders and QRX-series receivers were very good, even synthesizing left-right stereo into
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