Entries found for search: microphone
bi-directional microphone : A figure-eight microphone.
boundary microphone : A boundary microphone uses a small
condenser microphone capsule mounted very near a sound reflecting plate, or boundary, so there is no delay in the reflected sound. Direct and reflected sounds add in-phase over the audible range of frequencies
, resulting in a flat response, free of
phase cancellations, excellent clarity and
reach, and the same
tone quality anywhere around the microphone. Boundary microphones have a
directional response that is either half-
cardioid or half-
supercardioid. An example of a boundary microphone is a
PZM (pressure zone microphone).
Calrec Soundfield microphone : See Soundfield microphone.
cardioid microphone : A directional microphone with an acceptance angle that is most sensitive to sounds coming from the front and sides, while rejecting sounds coming from the rear. Called cardioid because the polar pattern of the microphone is roughly heart-shaped. All directional mics have a proximity effect, whereby sound sources close to the mic will have an exaggerated low-frequency response.
Supercardioids and hypercardioids are cardioids, but with a trade-off in the rear lobe. When using supercardioids and hypercardioids as sound reinforcement mics, it is important to note that the maximum rejection is not directly behind the mic as it is with a cardioid, but is off to the side between 110¢ª-126¢ª. However, a pair of hypercardioid microphones used as a
stereo X-Y pair yields a very clean cardioid response pattern. See pressure gradient.
condenser microphone : A condenser, or capacitor, mic capsule has a conductive diaphragm and a metal backplate placed very close to the diaphragm. They are charged with static electricity to form two plates of a capacitor. When sound waves strike the diaphragm, it vibrates, varying the spacing between the plates. In turn, this varies the capacitance and makes a signal analogous to the incoming sound waves. There are two types of condenser mics: the true condenser and the electret condenser. In the former, the diaphragm and backplate are charged with a voltage from a circuit. In the latter, the diaphragm and backplate are charged by an electret material, which is in the diaphragm or on the backplate. All true condenser mics need a power supply to operate, such as a battery or phantom power. In general, condensers have a smooth, detailed sound with a wide, flat frequency response--usually up to 15kHz-20kHz, useful for cymbals or instruments that need a detailed sound, such as acoustic guitar, strings, piano, or voice. Condenser mics tend to be more expensive and fragile than dynamic microphones. Note that omnidirectional condenser mics have deeper lows than cardioid condensers, making the former a good choice for pipe organs and bass drum. See also boundary microphone.
contact microphone : A mic that is physically attached to the body of an instrument or other sound source. It is primarily the vibration of the contact microphone’s body itself that is the transducer. By comparison, other microphones contain an internal diaphragm or membrane that vibrates in response to sound carried to it through the air, while the capsule of the microphone itself remains motionless. See also bug, piezo pick-up.
cosine microphone : See figure-eight microphone.
cottage loaf microphone : See supercardioid or hypercardioid microphone. UK usage.
electrostatic microphone : A class of microphone, of which condenser and electret are types, in which air pressure changes cause changes in the capacitance of a condenser. The capacitor is normally biased by a voltage which is supplied from batteries or via phantom power from the signal cable. The electret is an exception, as this requires such a small biasing voltage that it is possible to charge it permanently at the time of manufacture; Sennheiser mics use a proprietary biasing scheme which utilizes RF instead of a DC voltage.
figure-eight microphone : A directional microphone whose pick-up pattern resembles the figure 8, meaning that it is insensitive to the sides but has full sensitivity at the front and back. As the polar pattern resembles the shape of a cosine curve, the figure-eight microphone is sometimes also called a cosine microphone. Figure-eight mics were traditionally ribbon mics, but now they can also be condenser mics. Also called a bi-directional microphone.
gun microphone : A highly directional type of microphone used for long-distance recording, e.g., for wildlife or surveillance. Also called a rifle microphone, shotgun microphone, or interference microphone.
hypercardioid microphone : The narrowest of the unidirectional patterns, the hypercardioid is a variation on the cardioid microphone pick-up pattern which is most sensitive at the front and sides, while rejecting sounds entering 110°-250˚ to the rear, with a small lobe of sensitivity at 180˚ to the rear. The pick-up pattern of a hypercardioid is narrower than that of a supercardioid , and is somewhat similar to that of a figure-eight mic, but the response is asymmetrical in that the hypercardioid has greater sensitivity to sound arriving at the front of the capsule than to sound arriving a the rear. See acceptance angle. Also called a cottage loaf mic in the UK, for reasons related to bread.
interference microphone : See gun microphone.
Lavalier microphone : A small microphone, either condenser or dynamic, which can be easily hidden in a piece of clothing so as not to be seen by the camera. Also called a peanut microphone.
microphone : An electroacoustic device which delivers an electrical signal when actuated by a sound. A microphone consists of an acoustic system that supplies mechanical (acoustic) energy to a transducer, which converts the energy into electrical energy. Microphones are classified by their acoustical parameters, by their method of transduction, and by their directional characteristics. See capsule, cardioid, supercardiod, hypercardioid, ribbon microphone, moving coil microphone, condenser microphone, dynamic microphone, boundary microphone, Soundfield microphone, Lavalier microphone, contact microphone, and omnidirectional microphone.
microphone preamplifier : See preamplifier.
moving coil microphone : In a moving coil mic, a coil of wire is attached to a diaphragm and is suspended in a magnetic field. When sound waves vibrate the diaphragm, the coil vibrates in the magnetic field and generates an electrical signal similar to the incoming sound wave. For some reason, moving coil mics are called dynamic microphones, but not ribbon microphones.
spaced microphone recording : Stereo recording techniques including Decca trees, binaural, binaural synthesis, spaced pair, etc. which produce a large difference signal between the left and right channels. Spaced pairs should be placed directly in front of the sound source with a spacing of between one-half and one-third the width of the actual sound stage. Contrast with coincident pair.
Soundfield microphone : An extension of MS recording for ambisonic recording. This technique captures and reproduces true surround-sound, with height information as well as 360˚ horizontal imaging, as opposed to the artificial spatial position of various cinema surround systems. This is accomplished by six separate capsules which allow separate recording of left-right, front-rear, and up-down sound sources. Most use of these microphones is for stunningly accurate stereo recording.
shotgun microphone : See gun microphone.
rifle microphone : See gun microphone.
ribbon microphone : A type of dynamic microphone which has a thin metal foil, or ribbon, suspended in a magnetic field. Sound waves vibrate the ribbon in the field and generate an electrical signal. Ribbon mics are usually quite fragile, but are used for their warm, smooth tone quality. They work well with digital recording and on brass instruments to mellow the tone. Ribbon mics are either figure-eight bi-directional or cardioid. See also condenser microphone.
radio microphone : A mic with a built-in RF transmitter used instead of a cable connection to give a performer increased mobility. A receiver system picks up the transmitted signal for distribution to a PA, etc.
peanut microphone : See Lavalier microphone.
omnidirectional microphone : (Omni) A pressure operation microphone with a non-directional acceptance angle, i.e., one that is spherical, usually called an omni. See directional cardioid microphone.