Shure developed the mic element in the s, using small ports that allowed sound left to right, 55 “Fathead, 55S, S broadcast, 55SH Series II, Super stamp (with “The King”) that was issued by the U.S. Postal Service in Stay up-to-date, get the latest pro audio news, products and. Timeline of the Shure Unidyne Microphone Model 55 55S - $72; cardioid; add impedance selection switch (low-medium-high); "S" designation meant "Small". Shure 55SH Series II Unidyne Vocal Microphone - The Shure 55SH Series II is a "Get it" shows the next available date that we will be able to deliver this item to . the Gear4music extended warranty scheme provides an enhanced service.
Shure 55SH Series II Dynamic Microphone (the Elvis Microphone): withoutyouitsjustnot.us: Musical Instruments
Note that the time constant of an RC circuit equals the product of the resistance and capacitance. The voltage across the capacitor varies above and below the bias voltage. The voltage difference between the bias and the capacitor is seen across the series resistor.
The voltage across the resistor is amplified for performance or recording. In most cases, the electronics in the microphone itself contribute no voltage gain as the voltage differential is quite significant, up to several volts for high sound levels.
Since this is a very high impedance circuit, only current gain is usually needed, with the voltage remaining constant. The signal from the oscillator may either be amplitude modulated by the capacitance changes produced by the sound waves moving the capsule diaphragm, or the capsule may be part of a resonant circuit that modulates the frequency of the oscillator signal.
Demodulation yields a low-noise audio frequency signal with a very low source impedance. The absence of a high bias voltage permits the use of a diaphragm with looser tension, which may be used to achieve wider frequency response due to higher compliance. The RF biasing process results in a lower electrical impedance capsule, a useful by-product of which is that RF condenser microphones can be operated in damp weather conditions that could create problems in DC-biased microphones with contaminated insulating surfaces.
Condenser microphones span the range from telephone transmitters through inexpensive karaoke microphones to high-fidelity recording microphones. They generally produce a high-quality audio signal and are now the popular choice in laboratory and recording studio applications.
Microfiles: Shure Model 55—The History Of A True Classic - ProSoundWeb
The inherent suitability of this technology is due to the very small mass that must be moved by the incident sound wave, unlike other microphone types that require the sound wave to do more work. They require a power source, provided either via microphone inputs on equipment as phantom power or from a small battery.
Condenser microphones are also available with two diaphragms that can be electrically connected to provide a range of polar patterns see belowsuch as cardioid, omnidirectional, and figure-eight. A valve microphone is a condenser microphone that uses a vacuum tube valve amplifier. Electret condenser Main article: Electret microphone First patent on foil electret microphone by G.
An electret is a ferroelectric material that has been permanently electrically charged or polarized. The name comes from electrostatic and magnet; a static charge is embedded in an electret by alignment of the static charges in the material, much the way a magnet is made by aligning the magnetic domains in a piece of iron. Due to their good performance and ease of manufacture, hence low cost, the vast majority of microphones made today are electret microphones; a semiconductor manufacturer  estimates annual production at over one billion units.
Nearly all cell-phone, computer, PDA and headset microphones are electret types. They are used in many applications, from high-quality recording and lavalier use to built-in microphones in small sound recording devices and telephones. Though electret microphones were once considered low quality, the best ones can now rival traditional condenser microphones in every respect and can even offer the long-term stability and ultra-flat response needed for a measurement microphone.
Unlike other capacitor microphones, they require no polarizing voltage, but often contain an integrated preamplifier that does require power often incorrectly called polarizing power or bias.
This preamplifier is frequently phantom powered in sound reinforcement and studio applications. Monophonic microphones designed for personal computer PC use, sometimes called multimedia microphones, use a 3. Stereophonic microphones use the same connector; there is no obvious way to determine which standard is used by equipment and microphones. Only the best electret microphones rival good DC-polarized units in terms of noise level and quality; electret microphones lend themselves to inexpensive mass-production, while inherently expensive non-electret condenser microphones are made to higher quality.
Dynamic Patti Smith singing into a Shure SM58 dynamic cardioid type microphone The dynamic microphone also known as the moving-coil microphone works via electromagnetic induction. They are robust, relatively inexpensive and resistant to moisture. This, coupled with their potentially high gain before feedbackmakes them ideal for on-stage use.
Shure 55SH Series II Unidyne Cardioid Dynamic 55SH SERIES II B&H
Dynamic microphones use the same dynamic principle as in a loudspeakeronly reversed. A small movable induction coilpositioned in the magnetic field of a permanent magnetis attached to the diaphragm. When sound enters through the windscreen of the microphone, the sound wave moves the diaphragm. When the diaphragm vibrates, the coil moves in the magnetic field, producing a varying current in the coil through electromagnetic induction.
A single dynamic membrane does not respond linearly to all audio frequencies. For this reason, some microphones utilize multiple membranes for the different parts of the audio spectrum and then combine the resulting signals. Combining the multiple signals correctly is difficult; designs that do this are rare and tend to be expensive.
On the other hand, there are several designs that are more specifically aimed towards isolated parts of the audio spectrum. The AKG Dfor example, is designed for bass response rather than treble. Ribbon Edmund Lowe using a ribbon microphone Ribbon microphones use a thin, usually corrugated metal ribbon suspended in a magnetic field. The ribbon is electrically connected to the microphone's output, and its vibration within the magnetic field generates the electrical signal.
Ribbon microphones are similar to moving coil microphones in the sense that both produce sound by means of magnetic induction. Basic ribbon microphones detect sound in a bi-directional also called figure-eight, as in the diagram below pattern because the ribbon is open on both sides.
Also, because the ribbon has much less mass it responds to the air velocity rather than the sound pressure. Though the symmetrical front and rear pickup can be a nuisance in normal stereo recording, the high side rejection can be used to advantage by positioning a ribbon microphone horizontally, for example above cymbals, so that the rear lobe picks up sound only from the cymbals.
Crossed figure 8, or Blumlein pairstereo recording is gaining in popularity, and the figure-eight response of a ribbon microphone is ideal for that application. Other directional patterns are produced by enclosing one side of the ribbon in an acoustic trap or baffle, allowing sound to reach only one side. The classic RCA Type DX microphone has several externally adjustable positions of the internal baffle, allowing the selection of several response patterns ranging from "figure-eight" to "unidirectional".
Such older ribbon microphones, some of which still provide high-quality sound reproduction, were once valued for this reason, but a good low-frequency response could be obtained only when the ribbon was suspended very loosely, which made them relatively fragile. Modern ribbon materials, including new nanomaterials,  have now been introduced that eliminate those concerns and even improve the effective dynamic range of ribbon microphones at low frequencies.
Protective wind screens can reduce the danger of damaging a vintage ribbon, and also reduce plosive artifacts in the recording. Properly designed wind screens produce negligible treble attenuation. In common with other classes of dynamic microphone, ribbon microphones don't require phantom power ; in fact, this voltage can damage some older ribbon microphones.
Some new modern ribbon microphone designs incorporate a preamplifier and, therefore, do require phantom power, and circuits of modern passive ribbon microphones, i. Also there are new ribbon materials available that are immune to wind blasts and phantom power. Carbon microphone The carbon microphone was the earliest type of microphone.
The carbon button microphone or sometimes just a button microphoneuses a capsule or button containing carbon granules pressed between two metal plates like the Berliner and Edison microphones.
A voltage is applied across the metal plates, causing a small current to flow through the carbon. One of the plates, the diaphragm, vibrates in sympathy with incident sound waves, applying a varying pressure to the carbon.
The changing pressure deforms the granules, causing the contact area between each pair of adjacent granules to change, and this causes the electrical resistance of the mass of granules to change.
The changes in resistance cause a corresponding change in the current flowing through the microphone, producing the electrical signal. Carbon microphones were once commonly used in telephones; they have extremely low-quality sound reproduction and a very limited frequency response range, but are very robust devices. The Boudet microphone, which used relatively large carbon balls, was similar to the granule carbon button microphones.
Carbon microphones found use as early telephone repeatersmaking long distance phone calls possible in the era before vacuum tubes. These repeaters worked by mechanically coupling a magnetic telephone receiver to a carbon microphone: One illustration of this amplifier effect was the oscillation caused by feedback, resulting in an audible squeal from the old "candlestick" telephone if its earphone was placed near the carbon microphone.
Piezoelectric A crystal microphone or piezo microphone  uses the phenomenon of piezoelectricity —the ability of some materials to produce a voltage when subjected to pressure—to convert vibrations into an electrical signal. An example of this is potassium sodium tartratewhich is a piezoelectric crystal that works as a transducer, both as a microphone and as a slimline loudspeaker component.
Crystal microphones were once commonly supplied with vacuum tube valve equipment, such as domestic tape recorders. They were difficult to match to early transistor equipment and were quickly supplanted by dynamic microphones for a time, and later small electret condenser devices.
The high impedance of the crystal microphone made it very susceptible to handling noise, both from the microphone itself and from the connecting cable. Piezoelectric transducers are often used as contact microphones to amplify sound from acoustic musical instruments, to sense drum hits, for triggering electronic samples, and to record sound in challenging environments, such as underwater under high pressure.
Pretty good for a design celebrating more than 75 years! Not only is the Model 55 one of the best looking mics ever made, it also introduced a breakthrough technology in using just a single dynamic element and achieving pattern control.
Up to that time, attaining anything other than an omnidirectional pattern meant using more than one diaphragm and combining their outputs. Shure developed the mic element in the s, using small ports that allowed sound waves to reach both sides of a diaphragm at different times, resulting in a more linear frequency response.
The element of the Model 55 was also suspended on springs dampened with foam to isolate the diaphragm from handling noise.
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- Manufacturing date of a vintage Shure microphone
- Timeline of Shure Unidyne Model 55
The combination of great sound, compact size, cardioid pattern and classic styling made the Model 55 an instant hit.
When introduced it came in three types: The next year, a new broadcast version offered an isolation mount called the model The broadcast version became the inand the three types were replaced with a single model that featured a multi-impedance selector switch at the rear of the mic head. It was available as the 55S standard and the shock mount broadcast version.
The larger 55 was discontinued the following year. Postal Service in The head shape of the smaller 55 has remained the same, but the base eventually changed to a more modern design with a built-in XLR connector.