How To Install Dome Tweeters

Not to exist confused with Twitter.

Cutaway view of a dynamic tweeter with audio-visual lens and a dome-shaped membrane.

1. Magnet
2. Voicecoil
3. Membrane
4. Pause

A tweeter or treble speaker is a special type of loudspeaker (unremarkably dome, inverse dome or horn-type) that is designed to produce loftier audio frequencies, typically deliver high frequencies up to 100 kHz. The name is derived from the high pitched sounds made by some birds (Tweets), especially in contrast to the low woofs made by many dogs, after which low-frequency drivers are named (woofers).

Operation [edit]

Polycell tweeter from an Infinity speaker, showing the components.

Ohm CAM 16 speaker with "egg tweeter".

Well-nigh all tweeters are electrodynamic drivers using a voice coil suspended within a fixed magnetic field. These designs operate by applying current from the output of an amplifier excursion to a gyre of wire chosen a vocalization ringlet. The voice coil produces a varying magnetic field, which works confronting the fixed magnetic field of a permanent magnet around which the cylindrical voice coil is suspended, forcing the voice curlicue and the diaphragm attached to information technology to motion. This mechanical movement resembles the waveform of the electronic indicate supplied from the amplifier'southward output to the phonation scroll. Since the roll is attached to a diaphragm, the vibratory motion of the voice coil transmits to the diaphragm; the diaphragm in plough vibrates the air, thus creating air motions or audio waves, which is heard as high sounds.

Modern tweeters are typically dissimilar from older tweeters, which were commonly modest versions of woofers. Every bit tweeter technology has avant-garde, dissimilar design applications accept become popular. Many soft dome tweeter diaphragms are thermoformed from polyester film, or silk or polyester textile that has been impregnated with a polymer resin. Hard dome tweeters are usually made of aluminium, aluminium-magnesium alloys, or titanium.

Tweeters are intended to convert an electrical signal into mechanical air motion with nothing added or subtracted, but the process is imperfect, and real-world tweeters involve tradeoffs. Among the challenges in tweeter design and industry are: providing adequate damping, to cease the dome's motion rapidly when the signal ends; ensuring suspension linearity, allowing high output at the low end of its frequency range; ensuring freedom from contact with the magnet assembly, keeping the dome centered as information technology moves; and providing adequate power handling without adding excessive mass.

Tweeters can also piece of work in collaboration with the woofers that are responsible for generating the low frequencies or bass.^[1]

Some tweeters sit outside the main enclosure in their ain semi-independent unit. Examples include "super tweeters" and the novel "egg tweeter" by Ohm. The latter plugs in and swivels to adjust the soundfield depending on listener position and user preference. The separation from the baffle is considered to be optimal nether the theory that the smallest baffle possible is optimal for tweeters.^[2]

Range [edit]

Well-nigh tweeters are designed to reproduce frequencies up to the formally defined upper limit of the human hearing range (typically listed equally 20 kHz); some operate at frequencies upward to approximately in between 5 kHz to twenty kHz. Tweeters with a greater upper range have been designed for psychoacoustic testing, for extended-range digital audio such as Super Audio CD intended for audiophiles, for biologists performing research on animal response to sounds, and for ambient sound systems in zoos. Ribbon tweeters accept been fabricated that tin reproduce 80 kHz^[3] and even 100 kHz.^[4]

Dome materials [edit]

All dome materials accept advantages and disadvantages. 3 backdrop designers look for in domes are low mass, loftier stiffness and good damping. Celestion were the outset manufacturers to fabricate dome tweeters out of a metal, copper. Nowadays other metals such as aluminium, titanium, magnesium, and glucinium, too as various alloys thereof, are used, existence both light and stiff just having low damping; their resonant modes occur higher up twenty kHz. More exotic materials, such as synthetic diamond, are also being used for their extreme stiffness. Polyethylene terephthalate flick and woven silk suffer less ringing, but are not almost as stiff, which can limit their very high frequency output.

In general, smaller dome tweeters provide wider dispersion of audio at the highest frequencies. However, smaller dome tweeters accept less radiating area, which limits their output at the lower end of their range; and they have smaller vocalisation coils, which limit their overall power output.

Ferrofluid [edit]

Ferrofluid is a suspension of very small (typically 10 nm) iron oxide magnetic particles in a very low volatility liquid, typically a constructed oil. A wide range of viscosity and magnetic density variants permit designers to add together damping, cooling, or both. Ferrofluid also aids in centering the vox scroll in the magnetic gap, reducing baloney. The fluid is typically injected into the magnetic gap and is held in place by the stiff magnetic field. If a tweeter has been subjected to elevated power levels, some thickening of the ferrofluid occurs, as a portion of the carrier liquid evaporates. In extreme cases, this can degrade the sound quality and output level of a tweeter, and the fluid must be removed and new fluid installed.

Professional sound applications [edit]

Tweeters designed for sound reinforcement and instrument applications are broadly similar to high allegiance tweeters, though they're normally not referred to as tweeters, only as "loftier frequency drivers". Central design requirement differences are: mountings congenital for repeated shipping and handling, drivers often mounted to horn structures to provide for higher sound levels and greater control of sound dispersion, and more robust vocalization coils to withstand the higher power levels typically encountered. Loftier frequency drivers in PA horns are frequently referred to equally "compression drivers" from the mode of acoustic coupling between the driver diaphragm and the horn pharynx.

Diverse materials are used in the structure of compression commuter diaphragms including titanium, aluminium, phenolic impregnated textile, polyimide and PET film, each having its own characteristics. The diaphragm is glued to a voice whorl former, typically fabricated from a different material from the dome, since it must cope with heat without trigger-happy or significant dimensional change. Polyimide picture, Nomex, and glassfibre are pop for this awarding. The intermission may be a continuation of the diaphragm and is glued to a mounting ring, which may fit into a groove, over locating pins, or be attached with motorcar screws. The diaphragm is generally shaped like an inverted dome and loads into a series of tapered channels in a central structure chosen a phase plug, which equalizes the path length betwixt various areas of the diaphragm and the horn pharynx, preventing acoustic cancellations between dissimilar points on the diaphragm surface. The phase plug exits into a tapered tube, which forms the start of the horn itself. This slowly expanding throat within the driver is connected in the horn flare. The horn flare controls the coverage design, or directivity, and as an audio-visual transformer, adds proceeds. A professional horn and compression driver combination has an output sensitivity of between 105 and 112 dB/watt/meter. This is essentially more efficient (and less thermally dangerous to a small voice coil and erstwhile) than other tweeter construction.

Types of tweeters [edit]

Cone tweeter [edit]

The cone tweeter from a Marantz 5G loudspeaker

Cone tweeters have the same bones design and form every bit a woofer with optimizations to operate at higher frequencies. The optimizations usually are:

• a very pocket-size and light cone and then information technology can movement rapidly;
• cone materials chosen for stiffness (e.g., ceramic cones in ane manufacturer'south line), or good damping backdrop (e.k., newspaper, silk or coated cloth) or both;
• a interruption (or spider) that is stiffer than for other drivers—less flexibility is needed for high frequency reproduction;
• small voice coils (3/four inch is typical) and light (thin) wire, which also helps the tweeter cone move chop-chop.

Cone tweeters were popular in older stereo hi-fi speakers designed and manufactured in the 1960s and 1970s as an culling to the dome tweeter (which was developed in the late 1950s). Cone tweeters today are often relatively inexpensive, but many of those in the past were of high quality, such every bit those made past Audax/Polydax, Bozak, CTS, JBL, Tonegen and SEAS. These vintage cone tweeters exhibited very flat frequency response, low distortion, fast transient response, a depression resonance frequency and a gentle depression-end roll-off, easing crossover pattern.

Typical of the 1960s/1970s-era was the CTS "phenolic ring" cone tweeters, exhibiting flat response from 2,000 to 15,000 Hz, low baloney and fast transient response. The CTS "phenolic ring" tweeter gets its proper name from the orangish-colored edge break ring that information technology has which is made from phenolic. It was used in many makes and models of well-regarded vintage speakers, and was a mid-priced unit.

Cone tweeters have a narrower dispersion characteristic that is the same as a cone woofer's. Many designers therefore believed this made them a skillful lucifer to cone midranges and woofers, allowing for superb stereo imaging. Notwithstanding, the "sweet spot" created by the narrow dispersion of cone tweeters is small. Speakers with cone tweeters offered the best stereo imaging when positioned in the room's corners, a common practice in the 1950s, 1960s and early 1970s.

During the 1970s and 1980s, the widespread introduction of higher quality audiophile discs and the advent of the CD caused the cone tweeter to fall out of popularity considering cone tweeters seldom extend past 15 kHz. Audiophiles felt that cone tweeters lacked the "airiness" of dome tweeters or other types. Nevertheless, many high-end cone tweeters remained in limited production by Audax, JBL and SEAS until the mid-1980s.

Cone tweeters are at present rarely used in mod how-do-you-do-fi usage and are routinely seen in low price applications such as manufactory motorcar speakers, meaty stereo systems, and smash boxes. Some boutique speaker manufacturers recently take returned to high-end cone tweeters, specially recreations of CTS phenolic ring models, to create a vintage-sounding product.

Dome tweeter [edit]

A dome tweeter is constructed by attaching a voice curl to a dome (made of woven cloth, thin metal or other suitable fabric), which is attached to the magnet or the top plate via a low compliance suspension. These tweeters typically do not have a frame or basket, but a elementary front plate attached to the magnet assembly. Dome tweeters are categorized by their voice whorl diameter, and range from 19 mm (0.75 in), through 38 mm (1.5 in). The overwhelming majority of dome tweeters soon used in hullo-fi speakers are 25 mm (1 in) in diameter.

A variation is the ring radiator in which the 'suspension' of the cone or dome becomes the major radiating chemical element. These tweeters have different directivity characteristics when compared to standard dome tweeters.

Piezo tweeter [edit]

A piezo (or piezo-electric) tweeter contains a piezoelectric crystal coupled to a mechanical diaphragm. An audio signal is applied to the crystal, which responds past flexing in proportion to the voltage applied across the crystal's surfaces, thus converting electrical energy into mechanical.

The conversion of electrical pulses to mechanical vibrations and the conversion of returned mechanical vibrations back into electric energy is the ground for ultrasonic testing. The active element is the heart of the transducer equally it converts the electric energy to audio-visual energy, and vice versa. The active element is basically a piece of polarized textile (i.e. some parts of the molecule are positively charged, while other parts of the molecule are negatively charged) with electrodes attached to two of its opposite faces. When an electric field is practical beyond the material, the polarized molecules volition align themselves with the electrical field, resulting in induced dipoles within the molecular or crystal structure of the material. This alignment of molecules volition cause the material to alter dimensions. This phenomenon is known every bit electrostriction. In improver, a permanently polarized material such every bit quartz (SiO₂) or barium titanate (BaTiO_iii) will produce an electrical field when the material changes dimensions as a result of an imposed mechanical force. This phenomenon is known as the piezoelectric effect.

Piezo tweeters rarely get used in high-finish audio because of their low fidelity, although they did feature in some loftier-end designs of the tardily '70s, such as the Celef PE1 in which they were utilised every bit a super tweeter in combination with a conventional dome tweeter. They are often used in toys, buzzers, alarms, bass guitar speaker cabinets, cheap calculator or stereo speakers and PA horns.^{[ citation needed ]}

Ribbon tweeter [edit]

A ribbon tweeter uses a very thin diaphragm (often of aluminum, or mayhap metalized plastic film) that supports a planar curlicue frequently fabricated past deposition of aluminium vapor, suspended in a powerful magnetic field (typically provided by neodymium magnets) to reproduce high frequencies. The evolution of ribbon tweeters has more or less followed the development of ribbon microphones. The ribbon is of very lightweight material and so capable of very high acceleration and extended high frequency response. Ribbons have traditionally been incapable of high output (large magnet gaps leading to poor magnetic coupling is the main reason). Simply higher power versions of ribbon tweeters are becoming common in large-calibration audio reinforcement line array systems, which tin serve audiences of thousands. They are attractive in these applications since about all ribbon tweeters inherently exhibit useful directional backdrop, with very wide horizontal dispersion (coverage) and very tight vertical dispersion. These drivers can easily be stacked vertically, edifice a loftier frequency line assortment that produces loftier sound pressure levels much further abroad from the speaker locations than exercise conventional tweeters.

Planar-magnetic tweeter [edit]

Some loudspeaker designers utilize a planar-magnetic tweeter, sometimes called a quasi-ribbon. Planar magnetic tweeters are generally less expensive than truthful ribbon tweeters, but are not precisely equivalent every bit a metal foil ribbon is lighter than the diaphragm in a planar magnetic tweeter and the magnetic structures are dissimilar. Ordinarily a sparse piece of PET film or plastic with a vox coil wire running numerous times vertically on the material is used. The magnet structure is less expensive than for ribbon tweeters.

Electrostatic tweeter [edit]

A Shackman MHT85 Electrostatic Tweeter.

An electrostatic tweeter operates on the aforementioned principles every bit a full-range electrostatic speaker or a pair of electrostatic headphones. This type of speaker employs a sparse diaphragm (mostly plastic and typically PET motion-picture show), with a thin conductive blanket, suspended between two screens or perforated metal sheets, referred to every bit stators.

The output of the driving amplifier is practical to the primary of a footstep-upward transformer with a center-tapped secondary, and a very loftier voltage—several hundred to several grand volts—is applied between the centre tap of the transformer and the diaphragm. Electrostatics of this type necessarily include a high voltage power supply to provide the high voltage used. The stators are connected to the remaining terminals of the transformer. When an audio signal is practical to the primary of the transformer, the stators are electrically driven 180 degrees out of stage, alternately attracting and repelling the diaphragm.

An uncommon way of driving an electrostatic speaker without a transformer is to connect the plates of a button-pull vacuum tube amplifier directly to the stators, and the loftier voltage supply between the diaphragm and ground.

Electrostatics have reduced even-lodge harmonic distortion because of their push-pull design. They likewise have minimal phase distortion. The blueprint is quite old (the original patents date to the 1930s), but occupies a very small segment of the market because of high costs, low efficiency, large size for full range designs, and fragility.

AMT tweeter [edit]

The Air Motility Transformer tweeter works by pushing air out perpendicularly from the pleated diaphragm. Its diaphragm is the folded pleats of movie (typically PET motion picture) around aluminium struts held in a stiff magnetic field. In past decades, ESS of California produced a series of hybrid loudspeakers using such tweeters, forth with conventional woofers, referring to them as Heil transducers after their inventor, Oskar Heil. They are capable of considerable output levels and are rather more sturdy than electrostatics or ribbons, but have similar low-mass moving elements.

Most of the current AMT drivers in utilize today are similar in efficiency and frequency response to the original Oskar Heil designs of the 1970s.

Horn tweeter [edit]

A horn tweeter is any of the above tweeters coupled to a flared or horn structure. Horns are used for two purposes — to command dispersion, and to couple the tweeter diaphragm to the air for higher efficiency. The tweeter in either instance is usually termed a compression driver and is quite different from more common types of tweeters (run across above). Properly used, a horn improves the off-axis response of the tweeter by controlling (i.due east., reducing) the directivity of the tweeter. Information technology tin can also improve the efficiency of the tweeter by coupling the relatively high acoustic impedance of the driver to the lower impedance of the air. The larger the horn, the lower the frequencies at which information technology tin work, since large horns provide coupling to the air at lower frequencies. In that location are different types of horns, including radial and constant directivity (CD). Horn tweeters may have a somewhat 'different' sonic signature than elementary dome tweeters. Poorly designed horns, or improperly crossed-over horns, have predictable issues in the accurateness of their output, and the load that they present to the amplifier. Perhaps concerned nearly the epitome of poorly designed horns, some manufacturers use horn loaded tweeters, just avoid using the term. Their euphemisms include "elliptical aperture" "Semi-horn" and "Directivity controlled". These are, withal, a form of horn loading.

Plasma or ion tweeter [edit]

Considering ionized gas is electrically charged and so can be manipulated by a variable electric field, information technology is possible to apply a small sphere of plasma as a tweeter. Such tweeters are called a "plasma" tweeter or "ion" tweeter. They are more than complex than other tweeters (plasma generation is not required in other types), just offer the advantage that the moving mass is optimally low, and then very responsive to the bespeak input. These types of tweeters are non capable of high output, nor of other than very high frequency reproduction, then are usually used at the throat of a horn structure to manage usable output levels. One disadvantage is that the plasma arc typically produces ozone, a poison gas, in small quantities equally a by-product. Because of this, German language-made Magnat "magnasphere" speakers were banned from import to the Us in the 1980s.

In the past, the dominant supplier was DuKane near St Louis in the US, who fabricated the Ionovac; also sold in a UK variant as the Ionophane. Electro-Vox made a model for a brusk time nether license from DuKane. These early models were finicky and required regular replacement of the prison cell in which the plasma was generated (the DuKane unit of measurement used a precision machined quartz cell). As a upshot, they were expensive units in comparison to other designs. Those who accept heard the Ionovacs report that, in a sensibly designed loudspeaker system, the highs were 'airy' and very detailed, though loftier output wasn't possible.

In the 1980s, the Plasmatronics speaker also used a plasma tweeter, though the manufacturer did non stay in business organisation very long and very few of these complex units were sold.

Encounter also [edit]

Wikimedia Commons has media related to Tweeters.

Look up tweeter in Wiktionary, the complimentary lexicon.

• Loudspeaker enclosure
• Sound crossover
• Full-range speaker
• Super tweeter
• Midrange speaker
• Woofer
• Subwoofer
• Plasma speaker

References [edit]

1. ^ "Domicile". How Stereo . Retrieved 2019-01-thirty .
2. ^ "Chicago Tribune: Chicago news, sports, weather, entertainment".
3. ^ Calford, M. B. (June 1987). "Hearing in Flying-Foxes (Chiropterae: Pteropodidae)". Australian Mammal Lodge: 97.
4. ^ "Archived copy". Archived from the original on 2022-06-12. Retrieved 2012-02-11 . {{cite web}}: CS1 maint: archived copy every bit title (link)

Source: https://en.wikipedia.org/wiki/Tweeter

Posted by: pennytimans.blogspot.com

Share this post