The Perfect Pickup: Mics

January 1, 2004


The process of selecting the right equipment for the station ofteninvolves careful research into the needs of the users, and thenmatching these needs to the available choices. The available budgetalso figures into this equation, but it can sometimes have someflexibility based on the features.

It's amazing how often this process is ignored when it comes toselecting a microphone. It's easy to think that a mic is a mic. Theyall pick up sound. They all cover the audio spectrum. In general thisis true, but the same careful consideration given to an audio processorcan be applied to a microphone. Just as an audio processor has its ownnuances and feel, so does a microphone.

For studio use, these nuances and the general specifications are thekey aspects to consider. The studio mic sees as much regular use as anyother piece of equipment, so a minor price difference should not be alimiting factor.

As a review, there are two general categories that can describe anymic. One category covers the mics electrical operation. The otherdetails its pickup pattern.

For the electrical aspect, all mics can be categorized as eitherdynamic or active (usually condensers). Dynamic mics are purely passivedevices. Sound resonates a diaphragm that creates a signal voltage.Ribbon mics, while not as common in regular use, are also categorizedas dynamic mics, but because of their low output level and fragileconstruction, are not typically found in regular use for radio.

The other electrical type of mic is the condenser. In condensermics, the pickup diaphragm affects a capacitor with an electricalcharge on it. As sound waves move the diaphragm the capacitancechanges, thereby causing changes to the electrical charge, whichresults in an output signal.

Both types are practical for use in a studio. Dynamic mics requireno external power, so they do not require any special installation.Most condenser mics operate on phantom power — a power supplythat is carried over the balanced audio path. Most current consoledesigns and mic preamps can provide phantom power. Some condenser micsuse batteries or require an external power supply.

Evaluating the sound quality of a dynamic or condenser mic is asubjective test. In general, condenser mics tend to cost more thandynamics. Some feel that condenser mics have a crisper, more presentsound. While either is suitable for use in a studio, dynamic mics areusually preferred for field use because they do not need batteries or aphantom power supply, which few portable devices can provide.

The second general categorization of mics deals with the pick uppattern. In most radio applications an omnidirectional or cardioidpattern is used. There are other directional patterns, includingsuper-cardioid, hyper-cardioid and figure eight or bidirectional, butthey are not as commonly used in on-air applications. Some studio micsoffer switchable patterns. This is a convenient feature in someapplications, but is usually not necessary for the single-function useof a mic in a studio.

All cardioid mics exhibit proximity effect. This is an increase inbass response as the signal source gets closer to the mic. Some micdesigns acoustically reduce this effect, which can prevent a mic'ssound from becoming boomy when used closely. Also, many cardioid micshave a bass roll-off switch to tailor the low-end response. Announcerslove proximity effect because of the richness it adds to the sound oftheir voices.

In a studio, either pattern will work, but most engineers prefer acardioid pickup. The cardioid pattern by nature reduces the level ofsounds from the side and rear of the microphone. This is particularlyuseful in a studio with more than one mic in use.

For field use, a cardioid mic is best when used only by one person.The reduction in unwanted sound is a benefit. However, if the mic willbe used for interviews where the mic is shared, an omnidirectionalpickup would ensure that all voices are heard equally.

The tonal quality of a mic is just as important as its application.As the first link in the audio chain, take the time to fully evaluateyour next mic choice. You may be surprised at what you hear.

Resource Guide
An overview of available mics for the studio

The Studio Projects C1 is acardioid condenser microphone with a 1.06" capsule, low-noise FETamplifier and balanced, transformerless output circuitry. It features aswitchable 10dB pad and a 6dB at 150Hz high-pass filter. It includes ashock-mounted elastic suspension, foam wind screen and a hard-sidecarrying case. The mic's frequency response is from 20Hz to 20kHz witha maximum input of 142dB. The output impedance is less than 200ohms. Itoperates on phantom power.
www.studioprojectsusa.com

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The Audio-Technica AT3060 is alarge-diaphragm, side-address, cardioid condenser element with a tubeoutput. It does not require a dedicated power supply or special cablebecause it operates exclusively on 48Vdc phantom power. Thehand-selected tubes are individually tested and aged to maintain peakperformance. The tubes are shock-mounted to dampen mechanically-coupledvibrations. Large coupling transformer improves the low-frequencylinearity. It features a 50Hz to 16kHz frequency response, 400ohmsoutput impedance, a 117dB dynamic range and a maximum input level of134dB. It includes a shock mount and protective pouch.
www.audio-technica.com

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The Rode Broadcaster is anend-address, cardioid mic with a 20Hz to 20kHz frequency response andan output impedance of 40ohms. This large-diaphragm condenser micincludes a unique on-air indicator LED that can be connected to astudio's warning light. It has an internal shock-mounted capsule toreduce structure-borne noise and a fine mesh pop shield to eliminateplosives. It is housed in a rugged stainless-steel body and features avoice-tailored low-cut filter. It includes the BM1 microphone holderand a zip pouch.
www.rodemicrophones.com

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The Electro-Voice RE27 N/D is alarge-diaphragm dynamic mic featuring the Electro-Voice Variable-Ddesign to reduce the significant increase in bass response from theproximity effect of the cardioid pickup. The N/DYM element designprovides a 6dB increase in sensitivity compared to other dynamic micdesigns. The integral wind and blast filter reduces breath noise andplosive transients. Frequency response is from 45Hz to 20kHz. Theoutput impedance is 150ohms. It has three selectable filters (bassroll-off, low-mid cut and high-frequency roll-off) to tailor thefrequency response. The mic includes a stand adapter, carrying pouchand hard-shell case.
www.electrovoice.com

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A hyper-cardioid condenser mic, theLawson Air features an original capsule design using a variantof the company's L47 capsule. The mic is a 48V phantom-powered, 1"large-diaphragm cardioid condenser mic with a six-micron gold-sputtereddiaphragm. The capsule diaphragms have been edge-connected for morewarmth, robust articulation and more resonant proximity effects. Themic features the Lawson Quick Change capsule system. The mic'ssolid-state circuit features a Neutrik transformer, hand-solderedall-discrete components and a gold-plated XLR connector. It features20Hz to 20kHz frequency response and 150ohms output impedance. Itincludes a shock-proof carrying case and swivel mic holder.
www.lawsonmicrophones.com

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The Sennheiser MD 421 II continuesthe tradition of the MD 421, which has been one of Sennheiser's mostpopular dynamic mics for more than 35 years. The large-diaphragm,cardioid dynamic element handles high sound-pressure levels. The micfeatures a five-position bass control switch to tailor the bassresponse. The frequency response is from 30Hz to 17kHz. The Nominaloutput impedance is 200ohms. To celebrate the 90th birthday of thecompany's founder, Fritz Sennheiser, a special-edition MD 421 SE withgold-plated hardware, a wooden case and a signed certificate wasissued.
www.sennheiserusa.com

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The AKG Acoustics C 4500B-BC is acardioid, condenser microphone with transformerless output. Itsall-metal housing and double-screening of all acoustically opensections of the microphone provide shielding capability. The C 4500B-BCoffers a front-end firing capsule position, electro-magnetic screeningand internal pop-filter. A 120Hz roll-off filter is integrated into theC 4500B-BC, while a 20dB pad allows users to replace dynamicmicrophones without changing the adjusted gain structure on associatedequipment. The low self-noise and high overload point of the AKG C4500B-BC offer a dynamic range of more than 135dB. The output impedanceis 200ohms and frequency response is 20Hz to 20kHz.
www.akgusa.com

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The Shure KSM27 is a side-addresscondenser microphone with a cardioid polar pattern. It has anexternally biased, 1" gold-layered diaphragm, low self-noise, a 20Hz to20kHz frequency response and a Class A, discrete, transformerlesspreamplifier. It features a subsonic filter to eliminate rumble frommechanical vibration below 17Hz, a switchable 15dB pad, athree-position switchable low-frequency roll-off filter, an integratedthree-stage pop protection grille and an internal shock mount. It canhandle an input level of 137dB. It includes a protective pouch.
www.shure.com

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Built by Audio-Technica and based on theA-T 40 Series, the Sound Performance Lab Nugget condenser micuses a 1" diaphragm and transformerless circuitry for accurate, musicalreproduction with a maximum input of 145dB SPL. It features aswitchable 50Hz high-pass filter and 10dB pad. The mic was designed forvocal and instrumental recording applications. A high-quality shockmount is included. The cardioid pattern has a 20Hz to 20kHz frequencyresponse, a 129dB dynamic range, 50ohms output impedance and a 78dBS/N. It includes a suspension shock mount.
www.spl-usa.com

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The Neumann TLM 103large-diaphragm, cardioid condenser microphone uses the transformerlesscircuit found in numerous Neumann microphones and features lowself-noise and high sound pressure level capability. The mic isavailable in satin nickel and matte black finishes. The mic providesflat frequency response to 5kHz with a 4dB presence boost in higherfrequencies. It is capable of handling sound pressure levels up to138dB. The K 103 large diaphragm capsule is based on the K 87, wellknown from the U 67/U 87 microphones.
www.neumannusa.com

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The Heil Sound Goldline Pro dynamicmic achieves a low handling noise by mounting the wide frequency,dynamic element into a sorbothane shock-mount system. The mic has alsobeen engineered to reduce the bass boost from proximity effect. Itfeatures a large aluminum 1.125" low-mass voice-coil assembly. Thephasing plug assembly has equally placed ports that sense audio frombehind the mic to produce a linear cardioid pattern. The frequencyresponse is from 40Hz to 18kHz. It has a 600ohm output impedance. Itincludes a wooden case. A shock mount is also available.
www.heilsound.com

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The SE Electronics Z-2200 featuresdiscrete Class A FET electronics with a transformer-coupled balancedoutput. The mic's frequency response is from 20Hz to 20kHz and canhandle a maximum input of 125dB. The audio response has a slight risetowards the high end. Its output impedance is less than 200ohms.Features include a 100Hz bass roll-off switch and a 10dB pad. Thepickup pattern is a fixed cardioid. The mic's gold-sputtered diaphragmmeasures 1.07". The mic has a 3dB to 6dB lower self-noise than thecompany's previous models.
www.seelectronics.com

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