Glossary


Balanced Circuit:

There are two types of microphone output circuits - Balanced and Unbalanced.

An unbalanced output carries the signal on a single electrical conductor (and a shield). The humming of a nearby power cable and other tyes of electrical interference can easily be picked up by this kind of circuit and will be audible, reducing the sound quality.

In a balanced output, the signal is carried on two conductors (and a shield). The signal on each conductor is at the same level but the opposite polarity (i.e. one signal is positive and one signal is negative). This cable too will pick up electrical interference, but a balanced microphone input amplifies only the difference between the two signals and rejects any part of the signal which is the same on each conductor. Audio-(-Audio)=Audio+Audio & Noise-Noise=0. This, in effect, gets rid of the electrical noise and leaves you with a strong audio signal.


Bidirectional:

A bidirectional polar pattern is also called a "figure of eight". A microphone with a figure of eight polar pattern picks up the sound from in front of the microphone and from the rear but not the side (at a 90 degree angle). Microphones with this Figure of Eight polar pattern are typically Ribbon or Large Diaphragm Microphones.


Cardioïde:

A cardioid microphone has the most sensitivity at the front and is least sensitive at the back. This isolates it from unwanted ambient sound and gives much more resistance to feedback than omnidirectional microphones. This makes a cardioid microphone particularly suitable for loud stages.


Compressie:

Different types of digital compression formats are as follows:

  • AAC – Apple compression format
  • FLAC – Lossless compression format
  • Ogg – Vorbis compression format
  • MP3 – Most popular compression format.
  • WAV – Digital audio format without compression and discards
  • WMA –Windows compression format
     

Compressor:

A compressor is a device that reduces the dynamic range of an audio signal. First a threshold is established. When the audio signal is louder than this threshold, its gain is reduced. The amount of gain reduction applied depends on the compression ratio setting. For example, with a 2:1 ratio, for every 2 decibels the input signal increases, the output is allowed to increase only 1 decibel. A variety of other parameters in the compressor will also affect its performance processing specific signals; attack time, release time and others are very important.


Condensator:

Condenser microphones are more sensitive, give a smooth, natural sound and need to be powered. They use an electrically-charged diaphragm & backplate assembly to form a soundsensitive capacitor. When sound sets the diaphragm in motion, the distance between the diaphragm and the backplate changes. This variation in spacing changes the capacity of the capacitor, and produces the electrical signal. All condenser microphones need to be powered: either by batteries in the microphone or by phantom power. 


Condensatormicrofoon:

Condenser microphones are more sensitive, give a smooth, natural sound and need to be powered. They use an electrically-charged diaphragm & backplate assembly to form a soundsensitive capacitor. When sound sets the diaphragm in motion, the distance between the diaphragm and the backplate changes. This variation in spacing changes the capacity of the capacitor, and produces the electrical signal. All condenser microphones need to be powered: either by batteries in the microphone or by phantom power. 


Decibel dB:

The decibel (dB) is not a unit of measure such as feet, inches, or pounds. The decibel is a comparison between two values and is an expression often used in electrical and acoustic measurements. The decibel is a number that represents a ratio of two values of a quantity such as voltage. It is actually a logarithmic ratio whose main purpose is to scale a large measurement range down to a much smaller and more useable range.  The form of the decibel relationship for voltage is: dB = 20 x log(V1/V2)


Diversity:

So-called “diversity” Radio mircophone receivers feature two separate antennas to ensure consistent signal reception. If the wireless signal becomes poor or even noisy on one antenna, the second antenna takes over the reception, so drop-outs and noisy signals are avoided. All Shure wireless products feature diversity reception to maximize reliability compared to non-diversity systems, which have only one antenna.


Dynamisch:

Dynamic microphones have a relatively simple construction and are therefore economical and rugged. They can handle extremely high sound pressure levels and are largely unaffected by extreme temperatures or humidity.

To capture sound, dynamic microphones use a diaphragm, a voice coil and a magnet. The rear of the diaphragm is attached to the voice coil, which is surrounded by a magnetic field. The sound picked up by the diaphragm moves the voice coil in this magnetic field and generates the electrical signal; an electrical representation of the picked up sound.


Dynamisch bereik:

This is the difference between the queitest and loudest sound that a mic can pick up. The two extremes of this range are the self noise of the microphone, and the highest sound pressure level the microphone can pick up. It is measured in decibels (dB).


Dynamische microfoon:

Dynamic microphones have a relatively simple construction and are therefore economical and rugged. They can handle extremely high sound pressure levels and are largely unaffected by extreme temperatures or humidity.

To capture sound, dynamic microphones use a diaphragm, a voice coil and a magnet. The rear of the diaphragm is attached to the voice coil, which is surrounded by a magnetic field. The sound picked up by the diaphragm moves the voice coil in this magnetic field and generates the electrical signal; an electrical representation of the picked up sound.


EQ Equalizer:

Equalization (EQ) or tone control is used to shape the frequency response (and sound quality) in some desired way. An equalizer has the ability to boost and/or cut the energy (amplitude) in specified frequency ranges. It may be used to acheive a flat frequency response of a whole system, or might be used creatively to colour the sound of a specific instrument.


Electret:

An Electret mic is similar to an Condenser mic. The capsule of a condenser microphone requires a polarizing voltage to charge the condenser element. An electret is a synthetic material that is permenantly polarized. This is attached to the backplate, meaning the mic does not require an external polarizing voltage. Nevertheless, an electret condenser microphone does requires power (either by battery or phantom power) to operate the preamplifier.

They are small, and like a condenser, are sensitive and give a smooth, natural sound.


Fantoomvoeding:

All condenser microphones require phantom power in order for them to operate. The 48 Volts (sometimes 12 V) is usually supplied to the microphone by a mixer and is carried along the microphone cable. Some condensers can be operated with an internal battery and are therefore suited for use with mixers & PC sound cards without phantom power.


Feedback:

During normal operation of any sound system, sound produced by a loudspeaker can be picked up by a microphone. This sound re-enters the system, is amplified and produced again by the speakers. This sound is picked up by the mic again and the cycle continues. This is known as feedback, as the sound is literally 'feeding back' into the system. At certain points this can cause the system to create a noisy, sustained “howl”.


Figure of Eight:

A microphone with a Figure of Eight polar pattern picks up the sound from in front of the microphone and from the rear, but not the side (at a 90 degree angle). Microphones with this Figure of Eight polar pattern are typically rIbbon or Large Diaphragm Microphones.


Frequentie:

This is how many times a sound or radio wave oscillates in one second and is usually measured in Hertz (Hz). The frequency of sound vibrations are directly linked to what we hear as pitch. The term frequency along with the values associated with it allow us to speak objectively about sound characteristics, rather than just referring to pitch alone.

In a wireless radio mic system, the audio is carried on a radio wave on a specific frequency. Both the transmitter and receiver must be set to the same frequency.


Frequentie response:

This is the range of frequencies, from the lowest to the highest, that a mic can pick up. It also describes how sensititive a mic is to particular frequencies, i.e., it may be more sensitive to some frequencies than others. There are generally two types:

  • Flat frequency response: All audible frequencies (20 Hz – 20 kHz) are picked up equally by the microphone. This is most suitable for applications where the sound source has to be reproduced without changing or “coloring” the original sound, e.g. for recording.
  • Tailored frequency response: A tailored response is usually designed to enhance a sound source in a particular application. For instance, a microphone may have a peak in the 2 – 8 kHz range to increase intelligibility for live vocals.

Gevoeligheid:

This is how mich electrical signal a microphone produces for a given sound pressure level (SPL). In most cases sensitivity is measured with a sound pressure level of 94 dB (1 Pascal). The higher the sensitivity, the “louder” the microphone. Measured in [mV/Pa] or [dB/Pa].


Grote diafragma:

The terms small and large diaphragm are used with condenser microphones. A large diaphragm has a diameter of at least 1 inch (2.54 cm). Large diaphragm microphones are popular for vocal recordings as they add harmonics to the sound which makes voices sound smoother. Small diaphragm microphones feature a flat frequency response and sound more natural. This is why they are popular for instrument recordings.


Halfcardioïde:

Microphones with a "half cardioid polar pattern" are usually boundary microphones that are mounted on a flat surface. They pick up sound in a cardioid manner only in the hemisphere above the mounting surface.


Hypercardioïde:

Hypercardioid microphones offer an even narrower pickup than supercaidioids and a greater rejection of ambient sound. But they also have some pickup directly at the rear, hence it is important to place monitor speakers correctly. Hypercardioids are most suitable when single sound sources need to be picked up in loud environments. They are the most resistant to feedback.


Impedantie:

This describes how resistant an electrical circuit is to the flow of alternating current (electricity) passing through it. It is measured in ohms. The lower the impedance, the more current can flow through the microphone. The output impedance of a microphone should be much smaller than the input impedance of the microphone input of a mixer.


Klein diafragma:

The terms small and large diaphragm are used with condenser microphones. A large diaphragm has a diameter of at least 1 inch (2.54 cm). Large diaphragm microphones are popular for vocal recordings as they add harmonics to the sound which makes voices sound smoother. Small diaphragm microphones feature a flat frequency response and sound more natural. This is why they are popular for instrument recordings.


MixMode:

Shure stereo in-ear personal monitoring (IEPM) systems offer a proprietary feature called MixMode. Stereo IEPMs receieve 2 seperate channels of audio - one for the left ear and one for the right (stereo mode). MixMode feeds both signals into both ears at the same time (mono) but lets you control the balance between the two. Your two signals might be a band mix and a vocal mix  - MixMode lets you balance the level of one against the other.


Omnidirectionele:

The omnidirectional microphone has equal sensitivity at all angles. This means it picks up sound evenly from all directions. Therefore, the microphone need not be aimed in a certain direction, which is helpful especially with lavalier microphones. A disadvantage is that an omni cannot be aimed away from undesired sources such as PA speakers, which may cause feedback.


Operating-frequentie:

Every wireless microphone system transmits and receives sound on a specific radio frequency, known as the operating frequency. The crucial part when using wireless systems is choosing the right operating frequency. You cannot combine randomly selected RF frequencies as the microphones may compete with each other, and each system may experience noisy interference and/or drop outs (loss of the wireless signal altogether). It is also not possible to use two wireless systems on exactly the same frequency in the same venue. Nor can you use two wireless microphones with just one receiver at the same time. More advanced systems offer greater frequency selection, flexibility and the ability to combine more receivers and transmitters to serve more users.


Permanently Biased:

The microphone capsule (membrane and backplate) in a condenser microphone requires polarizing voltage to charge the condenser element. If an electret (a synthetic polarized material) is attached to the backplate, the polarizing voltage does not need to be supplied externally. Nevertheless, an electret condenser microphone still requires power (by battery or phantom power) to operate the preamplifier.


Polar Pattern:

The polar pattern of a microphone describes its sensitivity to sound relative to the direction or angle from which the sound arrives. Or, more easily worded; how well the microphone “hears“ sound from different directions. The most common types of directionality are: Omnidirectional, Cardioid and Supercardioid.


Proximity Effect:

Every directional microphone (i.e. cardioid, supercardioid) has a so-called proximity effect. When a microphone moves closer to the sound source, there is an increase in bass response and, hence, warmer sound. Professional singers often work with this effect. To test this out, experiment with bringing the microphone closer to your lips when singing and listen for the change in sound.


Ribbon:

The ribbon is the component in a ribbon microphone that captures the sound. It is usually a piece of very thin electricity-conducting foil. It is suspended between the two poles of a powerful magnetic assembly; one end grounded to the pole pieces, the other end insulated. This design enables a signal voltage to be formed as the foil vibrates within the dense magnetic field.

Ribbon microphones are typically bidirectional. They pick up sounds from in front of the microphone and from the rear but not the side (at a 90 degree angle).


Ribbon Microfoon:

A ribbon microphone is a type of dynamic microphone and uses a ribbon to capture sound. The ribbon is usually a piece of very thin electricity-conducting foil. It is suspended between the two poles of a powerful magnetic assembly; one end grounded to the pole pieces, the other end insulated. This design enables a signal voltage to be formed as the foil vibrates within the dense magnetic field.

Ribbon microphones are typically bidirectional. They pick up sounds from in front of the microphone and from the rear but not the side (at a 90 degree angle).


Self-noise:

Self-noise is electrical noise in a system that is produced by the system itself. In electronics, all components produce their own noise so long as they are at any temperature above absolute zero. If electrons are moving there will be noise. Add the noise of the components and the circuits they are in that are part of the audio path together and you have the self-noise of the device. Similarly, when you combine many such devices together in an audio system you have the self-noise of the system. This self-noise represents the noise floor of the device or system. The difference between this noise level and the level of a signal in the device is the signal to noise ratio.


Supercardioïde:

Supercardioid microphones offer a narrower pickup than cardioids and a greater rejection of ambient sound. But they also have some pickup directly at the rear, hence it is important to place monitor speakers correctly. Supercardioids are most suitable when single sound sources need to be picked up in loud environments. They are very resistant to feedback.


THD:

Total Harmonic Distortion is a measure of how much electrical noise a device produces and is the most common audio measurement, except perhaps for frequency response. To perform this test, a single sine wave frequency of known harmonic purity is passed through the unit under test and then into the distortion-measuring instrument. Based on a reference measurement level, the instrument notches out the frequency used for the test, and passes the remaining signal through a set of band-limiting filters, adjusted for the bandwidth of interest (usually 20 Hz-20 kHz). What remains is noise, including any AC line [mains] hum or interference buzzes, etc., as well as all harmonic distortions generated by the unit.


Total Harmonic Distortion:

Total Harmonic Distortion is a measure of how much electrical noise a device produces and is the most common audio measurement, except perhaps for frequency response. To perform this test, a single sine wave frequency of known harmonic purity is passed through the unit under test and then into the distortion-measuring instrument. Based on a reference measurement level, the instrument notches out the frequency used for the test, and passes the remaining signal through a set of band-limiting filters, adjusted for the bandwidth of interest (usually 20 Hz-20 kHz). What remains is noise, including any AC line [mains] hum or interference buzzes, etc., as well as all harmonic distortions generated by the unit.


Transducer:

A transducer converts energy from one form into another. In the case of a microphone, it converts sound energy into an electrical signal. The two most common transducer types are Dynamic and Condenser.


Transducer type:

A transducer converts energy from one form into another. In the case of a microphone, it converts sound energy into an electrical signal. The two most common transducer types are Dynamic and Condenser.


Unbalanced circuit:

There are two types of microphone output circuits - Balanced and Unbalanced.

An unbalanced output carries the signal on a single electrical conductor (and a shield). The humming of a nearby power cable and other tyes of electrical interference can easily be picked up by this kind of circuit and will be audible, reducing the sound quality.

In a balanced output, the signal is carried on two conductors (and a shield). The signal on each conductor is at the same level but the opposite polarity (i.e. one signal is positive and one signal is negative). This cable too will pick up electrical interference, but a balanced microphone input amplifies only the difference between the two signals and rejects any part of the signal which is the same on each conductor. Audio-(-Audio)=Audio+Audio & Noise-Noise=0. This, in effect, gets rid of the electrical noise and leaves you with a strong audio signal.