Shakers

The $3.7 million conservation plan relies on grants, donations and public funds. This improves the bass response of the system. That decision would be made by a nonprofit corporation—the United Society of Shakers, Sabbathday Lake Inc.—whose board members are largely non-Shakers. These incorporate a small hole, (called a port), in the speaker cabinet to allow the low frequencies generated by the rear of the woofer cone to escape from the cabinet in phase with that radiated from the front of the cone. The agreement does not specify whether the property will become a park, museum or other public space should the Shakers die off. Many multi driver systems use a bass reflex, or ported, design. Under the agreement, the Shakers will sell conservation easements to the trust, allowing the village to ward off development and continue operating as long as there are Shakers to live there. 'Multi driver' refers to any speaker system that contains two or more separate drive units, including woofers, midranges, tweeters, and sometimes horns or supertweeters.

To preserve their legacy as well as their idyllic, lakeside property at Sabbathday Lake, Maine, the Shakers announced in October 2005 that they had entered into a trust with the state of Maine and several conservation groups. Home cinema systems generally include multi-driver systems. On Wednesdays at 5:00 they hold a prayer meeting which is followed by a Shakers Studies class. Despite its name, however, the unit is really a wireless receiver, amplifier and loudspeaker in a single box. At 6:00 it is supper time, the last meal of the day. So-called wireless loudspeakers are becoming popular in many applications, such as home theater, due to their convenience, removing the need to run speaker wire. Work will continue at 1:00 p.m. See also: Home theater in a box.

This is the main meal for the Shakers. It is important to note that the sound channels offered to the speakers may be original individual channels (normal 5.1) or they may decode additional channels from the surround channels (This distribution can be accomplished by a Dolby Digital EX decoder, a THX Surround EX decoder) or they may be simulated (where the two surround channels are spread to center rear or twin rear speakers. "Dinner" begins at 12:00. They include :. Work is interrupted at 11:30 for Mid-day prayers. There are various different speaker set-ups for home cinema speaker systems. Work for the Shakers begins at 8:30. See also sound reproduction, electronics.

This will be followed by Prayer and silent prayer, concluded with the singing of a Shaker hymn. See AudioSpotlights.com for more information. They may read two Psalms and then read from the Bible. There are currently two devices available on the market that use ultrasound to create an audible "beam" of sound: the Audio Spotlight and Hypersonic Sound. Morning Prayers will start. Pompei. At 8:00 a.m. The technology, termed the Audio Spotlight, was first made commercially available in 2000 by Holosonics, a company founded by Dr.

The daily schedule of a Shaker in Sabbathday Lake Village is as follows: The day will begin for many at 7:30 a.m., the Great Bell on Dwelling House rings calling every one to breakfast. Joseph Pompei of the Massachusetts Institute of Technology in 1998 (105th AES Conv, Preprint 4853, 1998) fully described a working device that reduced audible distortion essentially to that of a traditional loudspeaker. However, there is no evidence to suggest Mother Ann stated this. F. There is a legend that one of Mother Ann's predictions states that there will be a revival when there are only five Shakers left. These problems went unsolved until a paper published by Dr. The people sing and dance and a Mother Ann cake is presented. This technology was originally developed by the US (and Russian) Navy for underwater sonar in the mid-1960s, and was briefly investigated by Japanese researchers in the early 1980s, but these efforts were abandoned due to extremely poor sound quality (high distortion) and substantial system cost.

Now Mother Ann day is celebrated on the first Sunday of August. Anyone or anything that disrupts the path of the beam will disturb the dispersion of the signal, and there are limitations, both to the frequency response and to the dispersion pattern of such devices. They farm and practice a variety of handicrafts; a Shaker Museum, and Sunday services, are open to visitors. There are some criticisms of this approach. This community, founded in 1783, was one of the smaller and more isolated Shaker communities during the sect's heyday. This effect cannot be achieved with conventional loudspeakers, because sound at audible frequencies cannot be focused into such a narrow beam. The Sabbathday Lake community still accepts new recruits, as it has since its founding. A listener outside the beam hears nothing.

In the United States today there is one active Shaker community with four members at Sabbathday Lake, Maine. The practical effect of this technology is that a beam of sound can be projected over a long distance to be heard only in a small, well-defined area. Although there were six thousand believers at the peak of the Shaker movement, there were only twelve Shakers left by 1920. The air within the beam behaves in a nonlinear way and demodulates the ultrasound, resulting in sound that is audible only along the path of the beam, or that appears to radiate from any surface that the beam strikes. Shaker theology, its manifestation in material artifacts such as furniture and oval boxes, and the Ann Lee story have continually drawn the attention of outsiders either fascinated or repulsed by them. The ultrasound is modulated-- it consists of an audible signal mixed with an ultrasonic frequency. Believers have continually looked at the story of Ann Lee as a cornerstone of the theological architecture that has distinguished their church from other American religious groups. A transducer can be made to project a narrow beam of ultrasound that is powerful enough, (100 to 110 dBSPL) to change the speed of sound in the air that it passes through.

Some Shaker settlements, such as Pleasant Hill community in Kentucky, have become museums. Some speakers are electrostatically driven rather than via the usual electromechanical voice coil, thereby giving a more linear response; the disadvantage, however, is that the signal must be converted to a very high voltage and low current, which can be problematic for reliability and maintenance as they attract dust, and develop a tendency to arc, particularly where the dust provides a partial path; the point where the arc occurs often becomes more prone to arcing, as carbon builds up from the burned dust. Shakers could not have children, and although they did adopt, this was not a major source of new members. A newer implementation of the Flat Panel involves the panel and an "exciter", such as the NXT technology. Shaker products could not compete with mass-produced products that became available at a much lower cost. Flat panel loudspeaker designs also work well as electrostatic loudspeakers. People were attracted to cities and away from the farms. An advantage of flat panel speakers is that the sound is perceived as being of uniform intensity over a wide range of distances from the speaker.

Membership in the Shakers dwindled in the late 1800s for several reasons. Some progress has been made using such rigid yet damped material as styrofoam, and there have been several flat panel systems demonstrated in recent years. There are recordings available of Shaker songs, both documentation of singing by the Shakers themselves, as well as songs recorded by other groups (see external links). There are two, related problems with flat panel technology; firstly, that the flat panel is more flexible than the cone shape and therefore fails to move as a solid unit, and secondly that resonances in the panels are difficult to control, leading to considerable distortion in the reproduced sound. Patterson, have compiled books of these songs, and groups have been formed to sing the songs and perform the dances. These can then be either made in a neutral colour and hung on walls where they will be less noticeable, or can be deliberately painted with patterns in which case they can function decoratively. Some scholars, such as Daniel W. One such attempt is the development of flat panels to act as sound sources.

The Shakers composed thousands of songs, and created also many dances; both were an important part of the Shaker worship services. There have also been many attempts to reduce the size of loudspeakers, or alternatively to make them less obvious. Many contemporary Christian denominations incorporate this tune into hymnals, under various names, including "Lord of the Dance," adapted by English poet and songwriter Sydney Carter. In electronic digital to analog conversion, this is addressed by the use of Low-pass filters to eliminate the spurious upper frequencies produced; however, this approach cannot be used to solve the problem with this digital loudspeaker, since it is the last link in the audio chain. The most famed of Shaker songs is Simple Gifts, which Aaron Copland used as a theme for variations in Appalachian Spring. The tune was composed by Elder Joseph Brackett and originated in the Shaker community at Alfred, Maine in 1848. Even accounting for the vastly lower efficiency of speaker drivers at such high frequencies, the result was to generate an unacceptably high level of ultrasonics accompanying the desired output. Many of them were imitated from the sounds of Native American languages, as well as from the songs of African slaves, especially in the southernmost of the Shaker communities. Secondly, since this system is converting digital signal to analog, the effect of aliasing is unavoidable, so that the audio output is "reflected" at equal amplitude in the frequency domain, on the other side of the sampling frequency.

Many of the lyrics to Shaker tunes consist of syllables and words from unknown tongues, the musical equivalent of glossolalia. For example, a 16 bit system to be compatible with the 16 bit audio CD standard, starting with a reasonable 2 square inch driver for the least significant bit, would require a total area for the drivers of over 900 square feet. This method has a curious, and coincidental, similarity to some ancient Greek music notation. There are two problems with this design which led to its being abandoned as hopelessly impractical, however; firstly, a quick calculation shows that for a reasonable number of bits required for reasonable sound reproduction quality, the size of the system becomes very large. Scribes, many of whom had no formal musical training, used a form of music notation for this purpose: it used letters of the alphabet, often not positioned on a staff, along with a simple notation of conventional rhythmic values. The next least significant bit drives a speaker of twice this area, and so on. In Shaker society, a spiritual "gift" could also be a musical revelation, and they considered it to be important to record these musical inspirations as they occurred. The next least significant bit drives a speaker of twice the area (most often, but not necessarily, a ring around the previous driver), again to either full amplitude, or off.

The Shakers considered music to be an essential component of the religious experience, and created some of the most tuneful, idiosyncratic, and utterly singable music in American history. (This allows for high efficiency in the amplifier, which at any time is either passing zero current, or required to drop the voltage by zero volts, therefore theoretically dissipating zero watts at all times). She made a full theatrical art with her dance entitled Dance of The Chosen Ones in which the nature of the Shakers’ religious fervor was depicted. The design of these is disarmingly simple; the least significant bit drives a tiny speaker driver, of whatever physical design seems appropriate; a value of "1" causes this driver to be driven full amplitude, a value of "0" causes it to be completely shut off. Another example is Doris Humphrey, an innovator in technique, choreography, and theory of dance movement. Actual digital speaker driver technology not only exists, but is quite mature, having been experimented with extensively by Bell Labs as far back as the 1920s. Kaare Klint, an architect and famous furniture designer, used styles from Shaker furniture in his work. Unfortunately, the recent marketing of plasma displays as high-end television sets and computer monitors has caused the "me-too" labeling of many speakers as "plasma" which have nothing whatsoever to do with plasma [8], much as the advent of digital audio caused the marketing of a large number of "digital" headphones and speakers, when all drive-units are analog in nature.

By the middle of the 20th century, as the Shaker communities themselves were disappearing, some American collectors whose visual tastes were formed by the stark aspects of the modernist movement found themselves drawn to the spare artifacts of Shaker culture, in which "form follows function" was also clearly expressed. A lower-priced variation on this theme is the use of a flame for the driver [7], flames being commonly electrically charged. Shaker ways influenced many people to write books and adopt ways of life from Shakers. As might be guessed, problems of maintenance and reliability for this design tend to make it very unsuitable for the mass market; the plasma is generated from a tank of helium which must be periodically refilled, for instance. Shaker dances and songs are a main, but largely unrecognized, aspect of folk art. Since plasma has minimal mass, but is charged and therefore can be manipulated by an electric field, the result is a very linear output at frequencies far higher than the audible range. They were once the largest producers of medicinal herbs in the United States, and pioneers in the sale of seeds in paper packets. The most exotic speaker design is undoubtedly the plasma arc loudspeaker, using electrical plasma as a driver [5], once commercially sold as the Ionovac [6].

Their industry brought about many inventions like the screw propeller, Babbitt metal, the rotary harrow, the circular saw, the clothespin, the flat broom and the wheel-driven washing machine. Piezos have several advantages over conventional loudspeakers when applied to such purposes:. Shakers won respect and admiration for their productive farms and orderly communities. Computer speakers and portable radios are common examples. famous for its elegance and practicality. Piezoelectric transducers, frequently used as beepers in watches etc., are often used as tweeters in cheap speaker systems. They have a collection of furniture and utensils outside of Pittsfield, Mass. These include piezoelectric, electrostatic, and plasma arc loudspeakers.

The simple, honest architecture of their homes, meeting houses, and barns have had a long lasting influence on American architecture and design. Other technologies can be used to convert the electrical signal into an audio signal. For example, they had a continuous wooden device like a pelmet with hooks running all along the lintel level from which they hung the very light furniture pieces such as chairs when not in use. See more details here. Shaker interior spaces are characterized by an austerity and simplicity. However, in practice it was found necessary to use a very complex cone made up of various materials at different points along its length, in order to maintain the waveform traveling evenly. Shaker craftsmen made most things out of pine or other inexpensive woods and hence their furniture was light in color and weight. This created a very effective omnidirectional radiator (although it suffered the same "planarity" effect as ribbon tweeters for higher-frequency sounds) and eliminated all problems of multiple drivers, such as crossover design, phase anomalies between drivers, etc.

The ladder-back chair was a popular piece of furniture. As the waves moved down the truncated cone, the effect was to reproduce the omnidirectional soundwave, as with a cylinder that changed diameter. They never fashioned items with elaborate details or extra decorations, but only made things for their intended uses. This turned normal speaker driver design problems on their head; whereas the normal problem with designing a driver is how to keep the cone as stiff as possible (without adding mass), so that it moved as a unit and did not become subject to traveling waves on its surface, the Ohm drivers were designed so that the entire purpose of the electromagnetic driver was to generate traveling waves that traversed the cone from the electromagnet at the top downwards to the bottom. Shakers designed their furniture with care, believing that making something well was in itself, "an act of prayer". The Ohm model "F" speakers invented by Lincoln Walsh feature a single driver mounted vertically as though it were firing downwards into the top of the cabinet, but instead of the normal almost flat cone, having a very-much extended cone entirely exposed at the top of the speaker. They relied on their own skills and natural resources for all these as well as for providing for their family. Ribbon tweeters often emit sound that exits the speaker concentrated into a flat plane at the level of the listeners' ears; above and below the plane there is often less treble sound.

This combined with their dedication to hard work and perfection has resulted in a unique range of architecture, furniture and handicraft styles. Ribbon loudspeakers can be very fragile but recently designed planar tweeters have the metal film printed on a strong lightweight material for reinforcement. One of the major attributes of the Shakers was to build. The advantage of the ribbon loudspeaker is that the ribbon has very little mass; as such, it can accelerate very quickly, yielding good high-frequency response (although its shape is far from ideal). Shaker beliefs have generated a unique culture and ways of life that have enriched the cultural history of the United States as well as subsequently inspired many modern fields. The electrical signal is applied to the ribbon which vibrates creating the sound. The Shakers have also authored thousands of religious songs. The ribbon loudspeaker consists of a thin metal-film ribbon suspended between two magnets.

However, later on, Shakers developed precision dances and orderly rituals. The stiffness moves self resonances upward in frequency. Early Shaker worship services were unstructured, loud, chaotic and emotional. The dome is used because it is an easily manufactured stiff structure - as anyone who has attempted to crush an egg the long way can attest to. Mother Ann was arrested several times for disturbing the peace. Perhaps contrary to intuition, making the moving component in the form of a dome rather than an inverted cone does not help to direct sound evenly in all directions. Many outsiders who witnessed Shaker worship services thought that they were heretics and protested in front of their places of worship. Because the wavelength of high-frequency sound is short (approximately 15 mm at 20 kHz), tweeters must have a physically small moving component or they will create a "beam" of sound rather than sending sound omnidirectionally (as is usually desired).

Shakers worshiped in plain meetinghouses where they marched around, sang songs, danced, twitched and shouted. This design is typically used for tweeters and sometimes for mid-range speakers. Mother Ann said, "Labor to make the way of God your own; let it be your inheritance, your treasure, your occupation, your daily calling.". For high frequencies, a variation on the common dynamic loudspeaker design uses a small dome as the moving part instead of an inverted cone. Each member learned a craft and did chores. Amar Bose of MIT spent many years trying to reproduce this spherical wavefront by constructing a one-eighth sphere covered in small drivers that would be situated in the corner of a room, thus mimicking one-eighth of a spherical wavefront emanating from that corner; in practice this idea never became workable, but Bose's experience with combining multiple small drivers in one loudspeaker cabinet gave rise to the popular Bose speakers which use multiple four-inch drivers, either to direct sound rearwards to reflect it from a wall behind the speakers, for home use, or to provide high power capacity when aimed directly at the listeners, for professional use. The Shakers believed in the value of hard work and kept comfortably busy. Several approaches have attempted to remedy this by approximating the sphere.

It was that way because they considered shutters and carvings to be worldly things. A point source or a sphere that varies in size with the amplitude of the desired pressure wave would avoid this problem of beam-formation but is generally physically impossible or impractical. The Shakers worshiped in meetinghouses that were painted white and unadorned. This is especially a problem for high frequencies where the loudspeaker may be physically large compared to the wavelength of the sound being reproduced. One Shaker chair sold for US$ 500,000. One problem with loudspeakers is that the essentially-planar form of most loudspeakers creates a soundwave that is somewhat directional, that is, the intensity of the sound produced varies depending on the listener's angle relative to the central axis of the speaker. Because of this craftsmanship, original Shaker furniture is costly. are mainly due to advantageous interactions with a particular speaker-room combination.

A Shaker chair would take weeks to make because only one craftsman made it and put a great deal of effort into making sure every joint, corner and leg were correctly in place. It has been theorized by some of the audiophile world that the perceived differences in sound between amplifier/loudspeaker combinations are in fact only differences in their interaction with their environment, rather than absolute differences in sound quality; and similarly, that any perceived differences in speaker cables, past a minimum set of specifications regarding resistance, inductance, capacitance, etc. It was plain in style, durable, and functional. This interaction affects the speaker's electromechanical behavior and thus the load it represents to the amplifier, making it difficult to predict the sound a given system will produce in its intended environment without listening tests. Shakers were known for an exquisite style of furniture, known as shaker furniture. A complication is the interaction of the speaker with the listening environment. They made leather in New York for several years, but in selling herbs and garden seeds, in making "apple-sauce" (at Shirley), in weaving linen (at Alfred), and in knitting underwear they did better work. and optionally,.

The communism of the Believers was an economic success, and their cleanliness, honesty and frugality received the highest praise. Speaker specifications generally include:. The prescribed uniform costume with woman's neckerchief and cap, and the custom of men wearing their hair long on the neck and cut in a straight bang on the forehead, still persist; but the women wear different colors. In general a higher quality speaker will have a higher sensitivity rating, larger and or heavier magnet, and a higher X_max. Their spiritual directors are elders and "eldresses," and their temporal guides are deacons and deaconesses in equal numbers. As shown in this example, sometimes the speaker with the lower sensitivity rating outputs a far higher amount of acoustic watt output. Their insistence on the bi-sexuality of God and their reverence for Mother Ann have made them advocates of sex equality. However at full power may achieve 160+ decibels at 20% to 40% "true" efficiency.

The Shakers do not believe in the divinity or deity of Jesus, or in the resurrection of the body. 80 to 86 dB/(W·m) (sensitivity efficiency of 0.01%). The four virtues are virgin purity; Christian communism; confession of sin, without which none can become Believers; and separation from the world. A few top of the line woofers have a very low "sensitivity" rating i.e. Adam's sin was in sexual impurity; marriage is done away with in the body of the Believers in the Second Appearance, who must pattern after the Kingdom in which there is no marriage or giving in marriage. A higher X_max indicates that the driver can move a larger volume of air as power increases. The theology of the denomination is based on the idea of the dualism of God: the creation of man as male and female "in our image" showing the bi-sexuality of the Creator; in Jesus, born of a woman, the son of a Jewish carpenter, were the male manifestation of Christ and the first Christian Church; and in Mother Ann, daughter of an English blacksmith, were the female manifestation of Christ and the second Christian Church — she was the Bride ready for the Bridegroom, and in her the promises of the Second Coming were fulfilled. In closed or small environments (such as cars or bedrooms) it is far more important to have a speaker with a high X_max (cone eXcursion maximum) as opposed to high (dB/(W·m)) rating.

In 1838 the gift of tongues was manifested and sacred places were set aside in each community, with names like Holy Mount; but in 1847 the spirits, after warning, left the Believers. above 140 decibels. Children told of visits to cities in the spirit realm and brought messages to the community which they received from Mother Ann. The ratio of the sound output to the mass of the cone/coil combination grows significantly at high sound pressure levels i.e. A period of spiritual manifestations among the Believers began in 1837 and lasted through 1847. This is partly due to a very high magnetic field and partly to a high amplitude displacement (speaker cone pumping in and out). A peculiar, intense kind of spirituality began to develop under this unique arrangement. Current state-of-the-art loudspeakers can approach efficiencies of 70% or higher.

The Shakers struggled with complex human problems that have no simple answers, and they managed to set up and sustain a distinctive way of life with much appeal for more than two hundred years. True or absolute efficiency is the ratio of "desired" output power divided by total input power. The Shakers lived in "families" sharing a large house with separate entrances for each family within the "family"; thus the families were exclusively male or female — the sexes were segregated into separate living areas. As an example, a simple cheerleader's horn makes more sound output in the direction it is pointed than the cheerleader could by herself, but the horn did not improve or increase the cheerleader's total efficiency. When Shaker boys reached the age of twenty-one, they were given the choice to leave the Shaker religion and go their own separate way or to continue on as a Shaker. From a technical standpoint "sensitivity" is not the absolute reference of efficiency. Another way they could expand their community's population was to allow converts into the Shaker society to live and function as one. Large horn loudspeakers that used to be used in cinemas, were very efficient by today's hi-fi speaker standards.

The Shakers did not believe in procreation so therefore had to adopt a child if they wanted one. The better the matching, the higher the efficiency. The city of Shaker Heights, Ohio, population 29,000, a suburb of Cleveland, was originally a Shaker settlement. This is especially difficult at lower frequencies. At various times, the Shakers had eighteen major communities in eight states and six smaller communities in Florida and Indiana. The main reason for this low efficiency is the difficulty of achieving proper impedance matching between the acoustic impedance of the drive unit and that of the air. In 1910 the Union Village Society went into the hands of a receiver. The remainder is converted to heat.

Lebanon Society in 1894 established a colony at Narcoossee, Florida; the attempt of the Union Village Society in 1898 to plant a settlement at White Oak, Georgia, was unsuccessful. Only about 1% of the electrical energy put into the speaker is converted to acoustic energy. The Mt. Loudspeakers are very inefficient transducers. The numerical strength of the sect decreased rapidly, probably from 4000 to 1000 from 1887 to 1908, and there has been little effort made to plant new communities. This is called the "sensitivity" rating. The peak was probably reached between 1830 and 1850 at about 6000 members. The efficiency is measured as dB/(W·m)—decibels output for an input of one nominal watt measured at one metre from the loudspeaker usually on the axis of the speaker.

A short-lived community at Canaan, was merged into the communities in Mount Lebanon (in New Lebanon) and Enfield, Connecticut. The sound pressure level (SPL) that a loudspeaker produces is measured in decibels (dBSPL). In New York, the communal property at Sodus Bay was sold in 1828 and the community removed to Groveland, or Sonyea; their land here was sold to the state and the few remaining members went to Watervliet. In all cases, replacement or full repair of the driver are the only options. In Ohio later communities were formed at Watervliet, Hamilton county, and at Whitewater, Dayton county. The latter two typically happen when the amplifier dumps a large DC current into the speaker - a condition typical of a failing (or failed) amplifier. In 1811 a community settled at Busro on the Wabash in Indiana; but it was soon abandoned and its members went to Ohio and to Kentucky. Electrical damage occurs when the voice coil burns out.

McNemar was a favorite of Lucy Wright, who gave him the spiritual name Eleazer Riotht, which he changed to Eleazer Wright; he wrote The Kentucky Revival (Cincinnati, 1807), probably the earliest defense of Shakerism, and a poem, entitled A Concise Answer to the General Inquiry Who or What are the Shakers (1808). A large DC fed to the woofer may cause twisting or deformation of the voice coil such that it rubs against the pole-pieces or magnet. McNemar was won by Shaker missionaries in 1805, and many of his parishioners joined him to form the Union Village community in Turtlecreek Township, Warren County, Ohio, four miles west of Lebanon. In rare cases, a very loud signal may cause the coupling between the parts of the woofer to simply give way. A prominent part in this revival had been taken by Richard McNemar, a Presbyterian, who had broken with his Church because of his Arminian tendencies and had established the quasi-independent Turtle Creek Church. Physical damage occurs if the signal causes the woofer's cone displacement to exceed the safe X_mech limits for prolonged periods. In Kentucky and Ohio Shakerism entered after the Cane Ridge, Kentucky revival of 1800–1801, and in 1805–1807 Shaker societies were founded at South Union, Kentucky Logan county, and Pleasant Hill, Kentucky, Mercer County, Kentucky. Woofers will usually take a lot of power before burning out or suffering damage to their moving systems.

Shaker communities in this period were established in 1790 at Hancock, West Pittsfield, Massachusetts; in 1791 at Harvard, Massachusetts; in 1792 at East Canterbury, New Hampshire (or Shaker Village); and in 1793 at Shirley, Massachusetts; at Enfield, Connecticut (then also known as Shaker Station); at Enfield, New Hampshire (or "Chosen Vale"); at Tyringham, Massachusetts, where the Society was afterwards abandoned, its members joining the communities in Hancock and Enfield; at New Gloucester, Maine (since 1890: "Sabbathday Lake"); and at Alfred, Maine, where, more than anywhere else among the Shakers, spiritualistic healing of the sick was practiced. Most woofers (and mid-ranges) can easily take up to 1.5 times or more power than what they are rated for - however this is dependent on the particular driver and the duration of the abuse or overload. The Shakers never forbade marriage, but refused to recognize it as a Christian institution since the second coming in the person of Mother Ann, and considered it less perfect than the celibate state. A badly clipping amplifier may also damage the tweeter despite a crossover, since a clipped waveform generates high-frequency harmonics which can contain sufficient power to heat up the tweeter's voice coil. By 1793 property had been made a "consecrated whole" in the different communities, but a "noncommunal order" also had been established, in which sympathizers with the principles of the Believers lived in families. Thus, feeding a low frequency (or a DC) signal to a tweeter even though electrically it may be within the tweeter's specification may cause permanent damage to the tweeter. Under his rule and that of Lucy Wright (1760–1821), who shared the headship with him during his lifetime and then for twenty-five years ruled alone, the organization of the Shakers and, particularly, a rigid communalism (religious communism), began. Thus a tweeter rated for 50 W is meant to be used with a 50 W amplifier only if the signals below the tweeter's lower operating frequency are filtered out.

On his death he was succeeded by Joseph Meacham (1742–1796), who had been a Baptist minister in Enfield, Connecticut, and had, second only to Mother Ann, the spiritual gift of revelation. Tweeters are usually designed (and rated) keeping in mind that a typical music signal doesn't contain a lot of power or energy at the higher end of the audio spectrum. James Whittaker was head of the Believers for three years. The tweeters are usually the first to go under circumstances of abuse, since they have the lightest voice coil made of thin wire which easily melts if the temperature rises excessively. She died in Watervliet, New York on September 8, 1784. However they do have limits and exceeding them by a large factor almost always causes permanent damage. In 1781–1783 the Mother with chosen elders visited her followers in New York, Massachusetts and Connecticut. Loudspeakers are rugged devices and can take some amount of abuse.

The Watervliet members, as pacifists and non-jurors, had got into trouble during the American War of Independence; in 1780 the Board of Elders were imprisoned, but all except Mother Ann were speedily set free, and she was released in 1781. Some of the issues in speaker design are lobing, phase effects, off axis response and time coherence. The Society at Watervliet, organized immediately afterwards, and the New Lebanon Society formed a bishopric. Speaker designers will use an anechoic chamber (essentially a room with soundproofing that inhibits any reverberation or echo) to ensure the speaker will perform the way it is intended to. Lebanon), Columbia county, New York. Adjusting a design is done with instruments and with the ear. A spiritualistic revival in the neighboring town of New Lebanon sent many penitents to Watervliet, who accepted Mother Ann's teachings and organized in 1787 (before any formal organization in Watervliet) the New Lebanon Society, the first Shaker Society, at New Lebanon (since 1861 called Mt. The nature of speaker design is considered both an art and science.

The elders would watch over them through the windows, to make sure no physical contact happened. The inverse sound waves and external noise cancel each other out and produce near silence. The men and women were segregated to prevent them from touching one another during the epileptic-like fits that they fell into during worship. The headphones produce the inverse sound waves of the external noise. They used different staircases, doors and even sat on opposite sides of the room. A similar effect is used in sound-cancelling headphones. Each house was divided so that men and women did everything separately. The second most noticed will be an unsettling feeling.

The village was divided into groups or "families" that were named for points on the compass rose. The most prominent effect to the untrained ear will be a loss of bass response. Mother Ann arrived on August 6, 1774 in New York City, and in 1776 the Shakers settled in the township of Watervliet, near Albany, where a unique community life began to develop and thrive. This won't cause silence because reflections from surfaces diminish the effect somewhat but resulting in a major loss of sound quality. Another revelation bade her take a select band to America. This type of wiring error creates inverse sound waves which cancel out (to a degree) the sound of the other speaker. After this, she was chosen by the society as "Mother in spiritual things" and called herself "Ann, the Word" and also "Mother Ann". In this case, any motion one cone makes will be 180 degrees opposite the other.

While in prison in Manchester for 14 days, she said she had a revelation that "a complete cross against the lusts of generation, added to a full and explicit confession, before witnesses, of all the sins committed under its influence, was the only possible remedy and means of salvation". If both sets of wires for left and right (in a stereo setup) are not connected in phase, the speakers will be out of phase from each other. She was frequently imprisoned for breaking the Sabbath by dancing and shouting, and for blasphemy. All speakers have two wires that must connected from the source of the signal (the amplifier or receiver) to the speaker's input terminals in correct polarity, or phase. She rose to prominence in the movement through her dramatic urging of the Believers to preach more publicly concerning the Kingdom of God, and to attack sin more boldly and unconventionally. The Tapered Quarter Wave Pipe (TQWP) is an example of a combination of transmission line and horn effects. Distinctively, the followers of Mother Ann came to believe that she embodied all the perfections of God in female form. This compromise is extremely attractive and used 90 percent of the time in bass horns.

Like her predecessors the Wardleys, she taught that the demonstrations of shaking and trembling were caused by sin being purged from the body by the power of the Holy Spirit, purifying the worshiper. This reduces the theoretical output by 3, but it is still maybe 5 times the output of a simple speaker in a box (no horn). Like many others in the Quaker tradition, she believed in and taught her followers that it is possible to attain perfect holiness. This means instead of using the perfect large size length of say 10ft, they cut it off at a length of say 3.3ft. She was miserable in marriage, and by 1770 had begun to insist that the institution was not compatible with the Kingdom of God. To minimize the size, some bass horns are designed as a "modified" or "cut" horn. Although a believer in celibacy, she had, at her parents' urging, married Abraham Stanley (Standley, or Standerin), and bore him four children, all of whom died in infancy. Despite this, they are used about 70 to 90 percent of the time in large stadiums or arenas.

She joined the Wardleys in 1758. Designs that use horn woofers occupy a large space, and are heavy. Under the leadership of Mother Ann Lee, beginning in 1774, the work ethic and rejection of marriage for which they have ever since been known began to typify the movement. Some low frequency horns employ a folded horn design to conserve space.
. For the bass or low-frequency region the size of the horn becomes exceedingly large and impractical (3ft x 2ft x 2ft, for example). The original and proper name of the group is the United Society of Believers in Christ’s Second Appearing, but followers quickly adopted the derogatory nickname, Shaking Quakers, which had been given to them by their many detractors. This type has a very high efficiency and reasonably small size for reproducing mid to high frequencies.

The Wardleys' followers, when "wrestling in soul to be freed from the power of sin and a worldly life," writhed and trembled, purportedly under the influence of the Holy Spirit, so that they won the name Shakers; their trances and visions, their jumping and dancing, were like those of many other sects, such as the Low Countries dancers of the 14th and 15th centuries, the French Convulsionnaires of 1720–1770, or the Welsh Methodist Jumpers. A horn (like a cheerleader horn) is an enclosure which has a flare or cone shaped structure attached to the front of the driver (speaker). Under the leadership of James and Ann Wardley, husband and wife, the group became known for their intense, ecstatic worship. The baffle dimensions are chosen to get the desired response, with larger dimensions giving a lower frequency before the front and rear waves combine and cancel. Derived from a small branch of English Quakers who had adopted some of the doctrines of worship followed by the 'French Prophets,' as Londoners called the Camisards, who had been driven into English exile from the provinces of Vivarais and Dauphiné. A rectangular cross-section is more common than a circular one since it is much easier to fabricate in folded form than a circular cross-section. The first documented use of the term comes from a British newspaper reporter who wrote in 1758 that the worshippers rolled on the floor and spoke in tongues. The baffle may be folded in order to conserve space.

Its origin is probably similar to that of the term Quaker. A dipole enclosure in its simplest form is a driver located on a flat baffle. The name Shakers, and the variant, Shaking Quakers, originally pejorative, was applied as a mocking description of their rituals of trembling, shouting, dancing, shaking, singing, and glossolalia (speaking in strange and unknown languages). [4]. . The payoff is an extended low end response and a characteristic sound that's appealing to many. The Shakers of New England should not be confused with the religion of the Indian Shakers of the Pacific Northwest of North America. Transmission lines tend to be larger than the other systems, due to the size and length of the line required by the design.

Once boasting thousands of adherents, today the Shakers number less than a handful of people living in Maine. The transmission line system is a waveguide system in which the guide reverses the phase of the driver's rear output, thereby reinforcing the frequencies near the driver's F_s. Strict believers in celibacy, Shakers maintained their numbers through conversion and adoption. PR's do add considerable cost to the system, however. The Shakers are an offshoot of the Religious Society of Friends (or Quakers) that originated in Manchester, England in the early 18th century. Due to the lack of vent turbulence and vent pipe resonances, many prefer the sound of PR's to reflex ports. Passive radiators add a complication to vented systems which causes a notch in frequency response at the PR's free air resonant frequency and this causes a steeper rolloff below the drone's tuning frequency Fb and poorer transient response than standard vented loudspeakers.

Passive radiators are tuned by their mass (Mmp) and the way their compliance interacts with the compliance of the air in the box. They are also used to eliminate port turbulence and reduce power compression caused by high velocity airflow in ports. Passive radiators are used primarily to tune small volumes to low frequencies, where a port would need to be very long. Sometimes a passive radiator (PR) or drone, similar to a speaker driver but without an electrically activated voice coil, is used instead of a reflex port.

This enclosure is considerably harder to design and tends to be driver-specific. If the enclosure on each side of the woofer has a port in it then the enclosure yields a 6^th order band-pass response. The dividing wall between the chambers has the driver mounted on it and the panel opposite to it (or the chamber into which the driver faces) has a port. In its simplest form it has two chambers.

A 4^th order bandpass is really just the same as a vented box where the contribution from the driver is trapped in a sealed box which modifies the resonance of the driver. This enclosure is the most common as it lends itself to small size and reasonable bass. Reflex ports are tuned by amount of mass within the vent, using appropriate diameter and length to reach this point. The interior of such enclosures are also often lined with fiberglass matting for absorption.

Other types of enclosures attempt to improve the low frequency response or overall efficiency of the loudspeaker by using various combinations of reflex ports or passive radiating elements to transmit the energy from the rear of the speaker to the listener; these enclosures may also be referred to as vented/ported enclosures, bass reflex, transmission lines (see below). The drawback of these speakers is their low efficiency, due to the loss of the power absorbed inside the cabinet. In this case, the true suspension of the driver's cone is the air trapped inside the box which acts as a spring with very close to ideal behavior rather than the mechanical suspension of the speaker driver, which for this application must be very weak, just strong enough to keep the cone centered in the absence of any signal. The box is typically designed with a very small rate of leakage so that internal and external pressures can slowly equilibrate over time, allowing the speaker to adjust to changes in barometric pressure or altitude.

The closed-box or 'acoustic suspension' enclosure, rather than using a large box to avoid the effect of the internal air pressure, uses a smaller, tightly sealed box. The box is usually filled loosely with foam, pillow stuffing, fiberglass, or other wadding, converting the speaker's thermodynamic properties from adiabatic to isothermal, and giving the effect of a larger cabinet. The box must be large enough that the internal pressure caused when the driver cone moves backwards into the cabinet does not rise high enough to affect this. The designer trades off bass response for flatness; the larger the resonant peak in the bass, the lower the speaker will seem to reproduce, but the more over-emphasized the resonant frequency will be.

The loudspeaker driver's mass and compliance, i.e. the stiffness of the suspension of the cone, determines the resonant frequency and damping properties of the system, which affect the low-frequency response of the speaker; the response falls off very sharply below the cabinet resonant frequency (Fcb). A variation on the 'open baffle' is to place the loudspeaker in a very large sealed box. The most common enclosure types are listed below. For the purposes of this type of analysis, each enclosure has a loudspeaker topology.

Enclosures used for woofer and subwoofer are applications that can be adequately modelled in the low frequency range (approximately 100–200 Hz and below) using acoustics and the lumped component model. The Acoustic Center of the driver, or physical position of each driver's voice coil, dictates the amount of rearward offset to time-align the drivers. Sometimes the differences in reaction time of the different size drivers is addressed by setting the smaller drivers further back, by leaning or stepping the front baffle, so that the resulting wavefront from all drivers is coherent when it reaches the listener. Diffraction problems are addressed in the shape of the enclosure; avoiding sharp corners on the front of the enclosure for instance.

Home experimenters have designed speakers built from concrete sewer pipes for similar reasons. The speaker manufacturer Wharfedale has addressed the problem of cabinet resonance by using two layers of wood with the space between filled with sand. Problems with resonance are usually reduced by increasing enclosure rigidity, added internal damping and increasing the enclosure mass. Enclosures play a significant role in the sound production, adding resonances, diffraction, and other unwanted effects.

However, for many purposes this is impractical and the enclosures must use other techniques to maximize the output of the loudspeaker (called loading). An 'open baffle' loudspeaker is an approximation to this - the transducer is mounted on a simple board of size comparable to the lowest wavelength to be reproduced. Thus the rear soundwaves cannot cancel the front soundwaves. The ideal mount for a loudspeaker would be a flat board of infinite size with infinite space behind it.

The major role of the enclosure is to prevent the out-of-phase sound waves from the rear of the speaker combining with the positive phase sound waves from the front of the speaker, which would result in interference patterns and cancellation causing the efficiency of the speaker to be compromised, particularly in the low frequencies where the wavelengths are large enough that interference will affect the entire listening area. A loudspeaker is commonly mounted in an enclosure (or cabinet). When used with speakers that do not reproduce low frequencies well, a subwoofer will often be configured to reproduce both the LFE channel and all other bass in the system, the latter being referred to as "bass management". This is because most full-range speakers are incapable of delivering the acoustic power required by the LFE in movies or in some cases, music.

When teamed with a modern surround sound receiver and full range speakers, they are typically driven with the specific LFE (low frequency effects) output channel (the ".1" in 5.1, 6.1, or 7.1 specifications) provided by the receiver. Amplified subwoofers frequently accept both speaker-level and line-level audio signals. Extended periods of high volume bass can cause items throughout a room to "walk" on a flat surface until they fall off. A subwoofer's powerful bass can often cause items in the room or even the structure of the room itself to vibrate or buzz.

Placing it in the corner of a room may produce louder bass sounds. It can instead be hidden out of sight. For the same reason, the subwoofer does not need a special placement in the sound field (for example, centered between the Left Front and Right Front speakers). Because of this phenomenon, it is usually satisfactory to provide just a single subwoofer no matter how many individual channels are being used for the full-spectrum sound.

Localization starts to happen above the 150 Hz point. The very long wavelength of the very low frequency bass sounds reproduced by the subwoofer usually makes it impossible for the listener to localize the source of these sounds. Subwoofers often contain integrated power amplifiers that may incorporate sophisticated feedback mechanisms to assure the least distortion of the reproduced bass acoustic waveform. Because the range of frequencies that must be reproduced is quite limited, the design of the subwoofer is usually quite simple, often consisting of a single, large, down-firing woofer enclosed in a cubical "bass-reflex" cabinet.

A typical subwoofer only reproduces sounds below 120 Hz (although some subwoofers allow a choice of the cross-over frequency). This speaker (and its enclosure) is referred to as a subwoofer. Modern speaker systems often include a single speaker dedicated to reproducing the very lowest bass frequencies. A subwoofer driver is a woofer optimised for the lowest range of the audio spectrum.

A whizzer is a small, light cone attached to the woofer's apex around the dust cap. These employ an additional cone called a whizzer to extend the high frequency response. A full-range speaker is designed to have as wide a frequency response as possible. A tweeter is a loudpeaker which is capable of reproducing the higher end of the audio spectrum, usually from about 1 kHz to 20 or perhaps 35 kHz.

Mid-ranges typically appear where large (>16 cm or 8") woofers are used for the bass end of the audio spectrum. These are used when the bass driver (or woofer) is incapable of covering the mid audio range. The distinction between woofers and mid-ranges is blurred however since many woofers can operate up to 3 kHz. A mid-range loudspeaker, also known as a squawker is designed to cover the middle of the audio spectrum, typically from about 200 Hz to about 4-5 kHz.

The frequency range varies widely according to design and hence while some woofers can cover the audio band from 50 Hz to 3 kHz, yet others may only work up to 1 kHz. A woofer is a loudspeaker capable of reproducing the bass frequencies. [3]. However a loudspeaker of say, a rated impedance of 8Ω/100W can easily overload an amp designed purely with a resistive load of 8Ω/100W as a target.

A typical amplifier is most usually quoted for a given power into a resistive load. It is a combination of resistive, capacitive, inductive as well as mechanical effects. A dynamic loudspeaker presents a complex load to the amplifier as opposed to a pure resistance. The weight and damping of the cone in a dynamic speaker should be appropriate for the characteristics of the rest of the driver and enclosure in order to produce accurate sound.

Despite marketing claims, lighter and more rigid cones do not always sound better. Tweeters are subject to a unique set of variables and parameters; their design and construction is extremely variable. Generally, larger and more powerful magnets are associated with higher quality speakers. The size and type of magnets can also differ.

Baskets must be designed in order to preserve rigidity and are typically cast or stamped metal, although injection-molded plastic baskets are becoming much more common in recent years. Driver cones may be constructed of a variety of materials, including paper, metal, various polypropylenes, and kevlar. When a multi-frequency signal is applied, the complex vibration results in reproduction of the applied signal as an audio signal. The coil and the permanent magnet interact with magnetic force which causes the coil and a semi-rigid cone (diaphragm) to vibrate and reproduce sound at the frequency of the applied electrical signal.

When an electrical signal is applied, a magnetic field is induced by the electric current in the coil which becomes an electromagnet. The parts are held together by a chassis or basket. A typical suspension system includes the 'spider', which is at the apex of the cone, often of 'concertina' form; and the 'surround', which is at the base of the cone. In addition to the magnet, voice coil, and cone, dynamic speakers usually also include a suspension system to provide lateral stability and make the speaker components return to a neutral point after moving.

One magnetic pole is outside the coil, whilst the other is inside the voice coil. The gap is also where the magnetic field is concentrated. The coil is oriented coaxially inside the gap made with a permanent magnet. A "gap" is a small circular hole, slot or groove which allows the voice coil and cone to move back and forth.

The traditional design is a semi-rigid paper fibre cone and a coil of fine wire (usually copper), called the voice coil attached to the apex of the cone. Additional improvements to loudspeaker technology occurred in the 1970s, with the introduction of higher temperature adhesives, improved permanent magnet materials, and improved thermal management. Polypropylene and aluminium are also used as diaphragm materials. For Example, Paper cones (or doped paper cones, where the paper is treated with a substance to improve its performance) are still in use today, and can provide good performance.

acoustic suspension) and changes in materials used in the actual loudspeaker, led to audible improvements. Developments in cabinet technology (e.g. The quality of loudspeaker systems until the 1950s was, to modern ears, very poor. This winding usually served a dual role, acting also as a choke coil filtering the power supply of the amplifier which the loudspeaker was connected to.

The coil of the electromagnet is called a field coil and is energized by direct current through a second pair of terminals. These first loudspeakers used electromagnets because large, powerful permanent magnets were not freely available at reasonable cost. Voigt produced the first effective full range unit in 1928, and he also developed what may have been the first system designed for the home, although using electromagnets rather than permanent magnets. There is some controversy in that an application was made earlier by the Briton Paul Voigt but not granted until later.

Kellogg. Rice and Edward W. The moving coil principle was patented in 1924 by two Americans, Chester W. [2].

The modern design of moving-coil loudspeaker was established by Oliver Lodge in England (1898). This was soon followed by an improved version from Ernst Siemens in Germany and England (1878). Alexander Bell patented the first loudspeaker as part of his telephone in 1876. However, the first documented ^[1] device that might fit this description was created in 1881.

Nikola Tesla is believed to have put electrically charged carbon dust in a cup-shaped device to create the first telephone loudspeaker. . The loudspeaker is the most variable element in an audio system, and is responsible for marked audible differences between systems. The term loudspeaker is used to refer to both the device itself, and a complete system consisting of one or more loudspeaker drivers (as the individual units are often called) in an enclosure.

A loudspeaker, or simply speaker, is an electromechanical transducer which converts an electrical signal into sound. In SDDS, 7.1 is the same as 5.1 but adding center-left and center-right speakers in the front of the listener for better audio positioning. 7.1 channel sound in home theater is identical to 6.1 except that it has left and right rear speakers. 6.1 channel sound is similar to 5.1 but there is an added center rear channel.

This is usually achieved by an amplifier setting of 'large' or 'small' defining the speaker type. This speaker can reproduce the bass frequency from all the main channels or may only do so for those speakers incapable of doing so. A subwoofer (which is counted as ".1" channel because of the narrow frequency band that it reproduces). Left and right surround speakers.

Left, center, and right front speakers. This requires: