AKG Microphones
Michael Lvov

AKG Acoustics for a long time and with much success has been releasing a huge variety of microphones, many of which have been widely adopted in television production and broadcasting. In this article we will examine a few models.

The C12 Vintage Revival without exaggeration can be named the legend - for this model has become very popular among professionals. It would be enough to say that the condenser microphone C 12 RV with polar selectable patterns has been already produced for more than 40 years. Initially this microphone was meant for studio applications where its effectiveness reaches its maximum especially when recording vocalists. Manual assembly of each copy guarantees its quality. The result is extremely faithful reproduction of bass, good sounding midrange and transparency of trebles. Strictly speaking, its frequency range is 30 up to 2000 Hz, polar pattern - omnidirectional, cardioid or figure-8 selectable plus 6 intermediate variants; switchable attenuation of either - 10 or -20 dB; the C 12 Vintage Revival's sensitivity is 10 mV/Pa (-40 dBV) with the possibility to be increased by 10 dB with a built-in switch; electrical impedance - 200 ohms, diameter - 42 mm, length - 225 mm, weight does not exceed 680 g. This microphone is furnished with the following accessories:

• Elastic suspender;
• Connecting cable, 10 m long,
• Power supply unit N 12VR;
• Windscreen case W42;
• Aluminum case.

C 12 Vintage Revival	C 417 PP of MicroMic III series

Among additional accessories we should point out various cable modifications, the PF 80 windscreen, desktop and floor stands. This microphone is especially good at stage shoots of musical bands, playing "live" music, and offers high quality sound.

The C 417 PP MicroMic III family miniature lavaliere microphone is characterized by an omnidirectional polar pattern and suits perfectly for TV-program announcers, vocalists and other performance part-takers, constantly moving all around the studio or outdoor shooting stage. The microphone's small size makes it possible to practically imperceptibly attach it to an article of the talent's clothing or hide it in hairs, whereas the windscreen minimizes unwanted ambient noise when using the microphone out-of-doors, in the field, etc.

Microphone specifications:

• Type - condenser;
• Frequency response - 20...20000 Hz;
• Sensitivity - 10 mV/Pa;
• Impedance - 200 ohms;
• Dimensions - 7.5 x 15 mm;
• Weight - 8 g.

The furnished accessories include a windscreen, clamps for attachment to a tie or another article of clothing, whereas a phantom power adaptor, various power supplies and batteries as well as power supply units N 62 E and N 66 E, for 2 or 6 microphones respectively, are offered optionally.

The C 417 is available in three versions: PP with a 3-pin XLR-type connector and built-in universal phantom power adaptor for 9 up to 52 V; L - with a fixing mini-XLR connector to be used with the battery power supply B 29 L, the phantom power adaptor MPA III L or miniature AKG transmitters; PL - which is identical with L, but with a beige-colored microphone and cable.

Another lavaliere condenser microphone is the CK 55 L, with cardioid polar pattern. It is designed specifically for use with miniature AKG transmitters, attached to the talent's body or an article of clothing (for example, waist-belt) with the possibility to provide both the talent and TV-program audience with enough freedom in motion.

The microphone ensures natural sound reproduction with a little rise in frequency response at 10 kHz. The low-cut filter provides minimization of unwanted ambient noise.

The CK 55 L specifications:

• frequency range - 150...18000 Hz;
• sensitivity - 8.8 mV/Pa (-41 dB);
• s/n ratio - not less than 60 dB;
• impedance - 200 ohms;
• power requirement - 1.5...10 V (9...52 v with the MPA 3 L phantom power adaptor);
• current consumption - 2 mA;
• connector type - mini-XLR;
• cable length - 160 cm;
• dimensions - 8x23 mm;
• weight - 2.5 g.

C 426 B microphone

The C 426 B stereo microphone is notable for a very high quality sound reproduction. This condenser microphone with its improved (vs. previous models) extended dynamic range and sensitivity and linear frequency response has a significantly low self-noise level and cross talk. The sound sensitive elements are two gold-sputtered dual-diaphragm transducers arranged as a coincident pair. The microphone head can be rotated within a defined range to facilitate quick changeovers between M/S and X/Y setups. Two LEDs mounted on each rotating capsule provide quick visual verification of the capsule angle from a distance. Switches on the microphone shaft select a bass cut within the limits of 12 dB/octave 75Hz and - 10 dB pre-attenuation. The supplied remote control allows completely noiseless selection among nine polar patterns available for each capsule.

In addition, the supplied microphone kit comes complete with a shock mount/stand adapter, foam windscreen, 20 m long connecting cable and a sturdy carrying case, whereas power supplies for two or six microphones at one time and various stands are available as an option.

The microphone specifications:

• frequency range - 20...20000 Hz;
• polar patterns - omnidirectional, cardioid, figure-8 plus six intermediate patterns;
• sensitivity - 11 mV/Pa (-39 dBV) per channel;
• impedance - 200 ohms;
• phantom power - 9...52 V;
• current consumption - approx 2 mA per channel;
• dimensions - 42/33x235 mm;
• weight - 470 g.

C 4500 B-BC

No processing - broadcast ready! - Under this slogan AKG released its C 4500 B-BC broadcast-class microphone. The development of this state-of-the-art model has been caused not to the lesser degree by the fact that all modern on-air studios become more clustered with computer equipment. These computers and their associated monitors radiate electro-magnetic RF fields which can be a serious problem for nearby dynamic microphones. Not so with condenser microphones with transformerless output, inherently immune to external electro-magnetic fields. The microphone suits perfectly for on-air radio and TV announcers, especially if the RF noise is caused by a nearby newsroom with plenty of computers installed in it. The major issues of this new development are:

• The front-end firing capsule position for most effective close-to-the-mouth placement with the least visual disturbances for the radio announcer;
• Improved off-axis noise rejection by inherent minimum working distance to the capsule of about 2 to 3 inches;
• Extremely effective internal pop-screening through a newly developed (patent applied for) multi-layer pop filter between the front grille and the capsule;
• An additional 120 Hz roll-off filter for both, further reduction of remaining proximity effect and suppression of rumble or structure-born noise;
• No need for additional sound processing;
• Highly effective electro-magnetic screening by the use of an all-metal housing and double screening of all acoustically open sections of the housing;
• The included spider suspension H 100 keeps problematic low frequency vibrations away from the microphone and also protects the microphone from abuses of more temperamental talents in front of it;
• The included W 4000 is a cellular foam wind and pop screen offering additional protection when working close to the C 4500 B-BC.

Specifications:

• frequency range - 30...20000 Hz;
• polar pattern - cardioid;
• pre-attenuation pad - -20 dB, switchable;

Pre-amplifier C 480 B separately (left) and with CK 69-ULS capsule

• bass-cut filter - 6 dB/octave below 120 Hz;
• sensitivity 1000Hz - 20 mV/Pa (-34dBV);
• electrical impedance - < 200 ohms;
• phantom power to DIN 45596 - 9...52 V;
• current consumption < 2 mA;
• dimensions - 58x183 mm;
• weight - 450 g.

Condenser microphones and preamplifiers of the Ultra Linear family are worth paying close attention to. They are notable for small-size diaphragms and meeting the strictest requirements of today's television production. The linearity of all major parameters make them a powerful tool in situations when faithful sound reproduction with neither distortion nor coloration is required. Owing to an extremely low self-noise level together with a high overload point, these microphones are extremely good for digital studio recordings. Moreover, a great number of accessories and various capsules allows to successfully solve practically any problem when working in studio. All aforesaid completely refers to the C 480 B pre-amplifier. This model is unique for its excellent specifications and operational flexibility. Its patented electronic circuitry coupled to a transformerless output stage assures completely linear transient characteristics across the entire audio bandwidth, while achieving self-noise figures close to the theoretical minimum for such class of devices. The C 480 B's dynamic range exceeds 125 dB. The gold-plated switch and connector contacts guarantee consistent performance. 48 V power supply is required for the microphone to be phantom-powered. Two sets of switchers offer a two-step high pass filter, and two gain manipulation stages of either - 10 dB or + 6 dB. Its frequency range is 20 to 30000 Hz, electrical impedance - < 150 ohms, dimensions - 21x150 mm, weight - 110 g.

The CK 69-ULS super-cardioid shotgun-type capsule is designed specifically for use in conjunction with the C 480 B. In fact, it is two shotgun capsules in one body for quick and easy conversion from short to long shotgun applications, from directional to hypercardioid polar pattern with no signal degradation. In its long shotgun configuration, the CK 69-ULS will deliver perfect results for film/TV outdoor applications or indoor front-of-stage recording from approximately 6 to 8 meters. This is particularly useful when shooting press-conferences as well as various events when there's no possibility to come up closer to a speaking person or another sound source. If you unscrew the front half of the interference tube, the same capsule becomes a short shotgun for use in TV, film or video close-up work. Both capsule configurations deliver outstanding sound quality with off-axis noise cut-off. Moreover, the capsule operates flawlessly in high humidity environments, and windscreens protect from unwanted ambient noise. Technical specifications of the CK 69-ULS (measured in conjunction with the C 480 B):

• frequency range - 20...18000 Hz;
• polar pattern - super-cardioid;
• sensitivity - 54, 27 and 8.5 mV/Pa (-25, -31 and -41 dB) switchable;
• dimensions - 21x176/317 mm;
• weight - 70 g.

A special part amongst AKG products intended for TV applications take radio systems providing wireless sound signal transmission from the video camera to the destination equipment (sound-mixer, recorder, etc.) thus giving the cameraman enough mobility and freedom in motion around the shooting scene. The AKG wireless system consists of the PR 81 receiver and the HT 81 and PT 81 transmitters. The receiver is camera-mountable and has a mini-XLR-type connector. The outstanding features of the PR 81 are 15 selectable channels for use in multi-channel systems, 4-stage antenna control system, dynamic range adjustment capability, compatibility with the WMS 80 and WMS 81 transmitters. Basic features of the transmitter:

• frequency range - 710...865 MHz;
• modulation - FM;
• audio frequency range - 50...20000 Hz;
• s/n ratio - 108 dB ( A -weigted);
• battery life (2x1.5 V AA -size) - not less than 5 hrs;
• audio output - unbalanced;
• dimensions - 92x65x20 mm;
• weight - 80 g.

The PR 81 is equipped with two antennas that allow to receive a signal sent by the transmitter in two, separated in space, locations. The specially engineered receiver circuitry automatically activates an antenna with a stronger signal, thus, higher capture ratio, i.e. the unit represents a true diversity wireless system.

The HT 81 transmitter is engineered as a hand-held device, which is most frequently, at work, combined with a microphone to deliver the same performance quality as traditional wired microphones would. This transmitter works in 3 MHz wide sub-band across the frequency range of 710 to 960.9 MHz and may also be tuned to one of 15 channels, depending on the specific situation. The transmitter uses a dipole-type antenna incorporated into its housing. The HT 81 can be used for practically any broadcast purpose thanks to a vast variety of capsules available. But it is especially effective when shooting big concerts or talk-shows, working outside the studio at mass meetings, etc.

PT 81 transmitter

Another transmitter, included in the AKG Wireless System, is the PT 81 to be attached to the talent's body. This transmitter is both dynamic and condenser microphone compatible. A 7 V source is required for power supply. The PT 81 takes a 3 MHz wide sub-band within a 710 to 869 MHz range and can be tuned to any of 15 selectable channels. The manufacturer recommends that one of the following microphone models be used with this transmitter:

• C 417 L;
• C 420 L;
• C 444 L;
• CK 77 L.

Sophisticated controls and LED indicators allow the engineer to follow the status and progress of the most important operational processes thus ensuring simple and effective wireless system operation.

By way of conclusion to this brief review of the microphones and wireless systems by AKG, it should be mentioned that high quality, outstanding durability and consistent functionality of these devices determine their popularity and preference for the most challenging events imaginable in the area of radio and television production.

"Slami&Co" Company.

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