What is a microphone cable shield? A microphone cable shield encloses and protects the signal wires inside a mic cable along its length. Shields are often made of conductive strands wound along the cable length. They reduce electromagnetic radiation from the cable and EMI into the cable, making them a critical in quality mic cables.
What is capacitance and what does it mean for condenser microphones? Capacitance is the ability for a system to store electric charge and is measured in farads (F). Condenser mic diaphragms are parallel-plate capacitors (diaphragm and backplate) and hold an electrical charge when powered. The capacitance varies as the diaphragm moves, causing a proportional mic signal.
Also known as a condenser.
What is a capacitor and how are capacitors used in microphones? A capacitor is a passive electrical component that stores an electrical charge in an electric field. They allow AC to pass while blocking DC. Most notably, condenser capsules even act as parallel plate capacitors, creating mic signals in proportion to their varying capacitance.
What is a microphone capsule? A microphone capsule is a mechanism that acts as the electroacoustic transducer, changing sound waves (mechanical wave energy) into mic signals (electrical energy). Capsules are often labeled by transducer type and polar pattern (ie: bidirectional ribbon element or cardioid condenser capsule).
For a detailed read on microphone capsules, check out my article What Is A Microphone Capsule? (Plus Top 3 Most Popular Capsules).
Also known as a button microphone.
What is a carbon microphone? A carbon mic creates a signal via a capsule with carbon granules pressed between two metal plates (diaphragm/backplate). A voltage across the plates causes a current through the granules. As the moving diaphragm alters the pressure and resistance of the granules, a low-quality mic signal is outputted.
Cardioid Polar Pattern:
What is the cardioid microphone polar pattern? The ideal cardioid microphone polar pattern is a directional pattern that is most sensitive in the mic’s on-axis direction with a null point in the exact opposite direction and a gradual attenuation in between that reaches -6 dB at 90° and 270°. The cardioid pattern is the most common polar pattern.
For more information on the cardioid polar pattern, check out my article What Is A Cardioid Microphone? (Polar Pattern + Mic Examples).
Also known as the Theile trapezoid or cardioid trapezium
What is the cardioid trapezoid miking technique? The cardioid trapezoid surround sound miking technique consists of 4 cardioid mics facing backward, angled 60° from one another and spaced 60 cm apart in the shape of a trapezoid. Though not the greatest for capturing surround sound, It is great for recording audiences and ambient sound in tight spaces.
What is a microphone carrier signal? A microphone carrier signal is a radio signal (in the VHF or UHF range) that is modulated by a mic signal and essentially “carries” the mic signal within itself. Carrier signals are essential for wireless mics. They are modulated at the transmitter, sent through air, and demodulated at the receiver.
What is a microphone case? A microphone case either refers to the outer shell of the microphone body or to the carrying case of a microphone. The outer shells of mics help to protect the inner wiring and electronics and even sometimes provide extra protection from electromagnetic interference.
Cat’s Cradle Shock Mount:
What is a cat’s cradle microphone shock mount? A cat’s cradle shock mount is a style of microphone shock mount with an outer ring that hosts an isolated inner ring with elastic string material. The outer ring attaches to a mic stand while the inner ring holds the mic in place. Cat’s cradle mounts typically hold large-diaphragm side-address mics.
What is a centre-terminated microphone capsule? A centre-terminated mic capsule is a condenser capsule that has its electrical lead terminated at the centre of the diaphragm or backplate rather than at the edge. Though not a major factor, centre-terminated capsules, in theory, are less prone to plosives and have less diaphragm resonance.
What is a microphone channel? A microphone channel is a designated slot in an audio mixer or digital audio workstation for the recording and reproduction of a mic signal. Channels have volume, panning, sends, and sometimes have built-in equalization and compression units.
What is clip-on miking? Clip-on miking is the technique of attaching a mic to a sound source. Clip-on techniques include attaching lavalier mics in clothing and hair as well as attaching mics internally or externally to instruments. Clip-on mics generally yield isolated but unnatural captures of their sound sources.
What is microphone clipping? Microphone clipping is the overloading of the mic circuitry, the mic preamp, or the mic channel in the audio mixer or digital audio workstation. Clipping causes distortion in the mic signal.
For more information on microphone clipping, check out my article What Is A Microphone Clip? (Physical And Electrical).
What is a microphone clone? A microphone clone is a mic that is based on the design of another mic. Many boutique microphone manufacturers produce clones of famous and highly sought after vintage mics. Many live vocal mics are clones of the famous Shure SM58 (link to check the price on Amazon).
What is close-miking? Close-miking is the positioning of a mic close to its sound source, especially in the presence of other sources. Close-miking improves isolation by minimizing bleed and room sound. It adds clarity and flexibility in the mixing of the source. Close-mics are typically within 2 feet of their sources.
What is a coincident pair of microphones? A coincident pair of microphones it two of the same mic positioned together in such a way that sound waves arrive at them at [practically] the same time.
Coincident pair miking techniques include:
For more information on coincident pairs, check out my article What Is A Coincident Pair Of Microphones? (With 2 Techniques).
What is a coloured microphone? A coloured microphone does not have a flat frequency response. The term “coloured” means that a mic is more sensitive to some frequencies and less sensitive to other frequencies. Presence boosts, high-end roll-offs, and mid-frequency dips are all examples of “coloured” responses.
What does common-mode rejection mean in a mic signal? Common-mode rejection (CMR) is the cancellation of in-phase signals on pins 2 and 3 of a balanced XLR cable. Mic signals are sent down pins 2 and 3 in opposite polarity and are summed together at a mic preamp’s differential amplifier. CMR rids of interference that would be common to pins 2 and 3.
What does companding a wireless microphone signal mean? Companding (a portmanteau of compressing and expanding) is a process where a mic signal’s dynamic range is compressed before wireless transmission and then expanded to its original range at the receiver. Companding effectively reduces the detrimental effects of a channel with a limited dynamic range.
Also known as a capacitor or electrostatic microphone.
What is a condenser microphone? A condenser microphone is a transducer with a parallel-plate capacitor capsule that requires a steady electrical charge to produce a mic signal. The front plate (diaphragm) moves according to sound waves, causing a variation in capacitance and, therefore voltage (mic signal).
What is electrical conductance and how does it relate to a microphone? Electrical conductance (symbol: G) is the ease in which electric current flows in a medium and is measured in Siemens. Microphones need conductive wires to carry their electrical mic signals and condenser mics even need their diaphragms to be conductive. Conductance is the inverse of resistance.
What is constructive interference and how does it apply to microphones? Constructive interference is the summing of two (or more) signals or sound waves that results in a stronger signal or wave. Constructive inference helps to explain the tuning of acoustic environments and the function of balanced audio, which are both worth understanding when using microphones.
What is a contact microphone? A contact mic is designed to pick up sound vibration through contact with solids. Contact mics are largely insensitive to sound waves in air, which is a huge distinction from typical microphones. They are usually piezoelectric mics used as acoustic leakage probes or acoustic instrument pickups.
What is the recording control room? A control room, when speaking of recording, is part of the recording studio. The control room hosts the mixing console, studio monitors, and digital audio workstation. The control room is where the actual recording, mixing, and mastering takes place and is often designed to be an acoustically dead space.
Controlled Magnetic Microphone:
Also known as the controlled reluctance microphone.
What is a controlled magnetic microphone? The controlled magnetic microphone was a Shure trademark design and predecessor of the moving-coil dynamic microphone. It works with a ferrous rod (instead of voice coil) attached to a moving diaphragm inside a magnetic field. Electromagnetic induction produces the mic signal as the rod moves.
Corey/Martin Tree Technique:
What is the Corey/Martin Tree miking technique? The Corey/Martin Tree is a surround sound miking technique. Subcardioid mics face left, right and centre while cardioid mics point upward in the back. The left and right mics are 120 cm apart. The centre mic in the middle, 15 cm forward. The back mics are 30 cm apart and 60 cm behind the front pair.
What is a microphone’s critical distance? Critical distance refers to a mic position where the room sound (initial reflections, reverberation, and standing waves) becomes equally as strong as the direct sound source.
What is electrical current and how does it apply to microphones? The electrical current is the flow of electrical charge. It’s most often carried by the flow of electrons in a wire and is measured in amperes (A). Microphone signals are electrical and have alternating current. Active mics (like condensers) need electrical current to operate their internal circuitry.
What does it mean when a microphone has a current consumption? A microphone’s current consumption (measured in amperes) tells us how much current it will draw in order to operate. Only active microphones require electrical current and will “take what they need” when provided with an adequate power source (often phantom power).