Audio-Technica manual PRO45 and PRO45W, REMOTE-POWERED Cardioid Condenser Hanging Microphones

PRO45 and PRO45W

REMOTE-POWERED CARDIOID CONDENSER HANGING MICROPHONES

The microphone element is enclosed in a rugged housing with a low-reflectance black finish. The microphone is also available in white as the PRO 45W, with a white-finished microphone housing, windscreen, cable and steel hanger, for applications where the microphone must be hung against a light background.

Operation and Maintenance

The PRO 45 is ideal for suspension over choirs, instrumental groups or theater stages. A uniform 120° angle of acceptance provides well-balanced audio pickup. The microphone should be located forward of the front-most source, above the rear-most source, and “aimed” between them (Fig. 1). Increasing the height of the mic above the sources will tend to equalize sound levels between them, but may also increase background/reverberant sound pickup. Whenever possible, the distance from the mic to the rear-most pickup should be no more than twice the distance to the front source, to maintain front-to-rear balance (Fig. 1).

DC phantom power (9-52 volts) must be applied equally to Pins 2 and 3, with the ground for the power supply connected to Pin 1. This can be provided by a console or mixer with built-in phantom voltage or with the addition of an in-line phantom power supply, such as the recommended Audio-Technica CP8506 and AT8801 power supplies.

If an extension cable is necessary, AT8314 cable (or equal) should be used. Regardless of cables used, it is important that both ends of each cable are wired consistently, with the shield always connected to Pin 1 at both ends, Pin 2 connected to Pin 2, and Pin 3 to Pin 3. This will ensure that all microphones are electrically in phase and reduce problems of uneven response and sound cancellation when two microphones are used close to each other.

The high sensitivity of the PRO45 ensures useful output and an excellent match to most mixer, tape recorder and amplifier inputs. It will provide undistorted output even in sound fields as loud as 134 dB SPL. However, due

Description

The PRO 45 is a wide-range condenser micro- phone with a cardioid (unidirectional) polar pattern. It was designed for high-quality sound reinforcement and other demanding sound

DISTANCE	LESS THAN 2	TIMES “X”
	“X”
120°
ANGLE OF
ACCEPTANCE

Fig. 1

120°	120°
MIC A	MIC B
	3 TIMES
	DISTANCE “X”

Fig. 2

to the high sensitivity, in some instances it may be possible to overload sensitive input stages. If distortion occurs, first check for input overload. In such cases, an attenuator such as the Audio-Technica AT8202 may be required between the mic and the electronics input. (Also, many mixers provide “input pad” switches to reduce mic-input signal levels.)

While a modern condenser microphone is not unduly sensitive to the environment, tempera-

pickup applications. The PRO 45 is furnished with a vinyl-coated steel hanger that allows it to be positioned inconspicuously over a choir, orchestra, stage, etc., for low-profile situations.

The PRO 45 features a 25' (7.6 m) perma- nently-attached miniature cable with an XLRM-type connector, which allows it to be plugged directly into an XLRF-type jack or cable connector. The unit’s integral electronics can be powered from any external 9V to 52V DC phantom power source.

Audio-Technica design engineers have utilized the newest low-mass technology in the quest for superior performance. The charge is now on the fixed back plate, rather than the moving element. With the A-T fixed-charge “back plate” construction, a gold-vaporized diaphragm just 2 microns thick (about 0.000079") can be used. This reduces moving mass substantially, improving frequency response and transient response while reducing distortion.

Width of pickup is approximately three times the distance to the closest performer. If addi- tional mics are needed for wide sources, they should not be closer together laterally than three times the distance to the front source, to avoid phase cancellation (Fig. 2).

To orient in the proper direction, twist the microphone housing slightly in its wire holder (clockwise rotation moves the microphone to the right; counterclockwise rotation moves it to the left). The provided AT8146 windscreen simply slips over the head of the microphone, effectively reducing noise from wind or venti- lation air currents.

Output is low impedance balanced. The output connector mates with XLRF-type connectors. The balanced signal appears across Pins 2 and 3, while the ground (shield) connection is Pin 1. Output is phased so that positive acoustic pressure produces positive voltage at Pin 2 in accordance with industry convention.

ture extremes can be harmful. Exposure to high temperatures can result in gradual and permanent reduction of the output level. Avoid leaving the microphone in the open sun or in areas where temperatures exceed 110° F (43° C) for long periods of time. Extremely high humidity should also be avoided.

		Frequency Response
									in dB
								10 dB	Response
50	100	200	500	1k	2k	5k	10k	20k
			Frequency in Hertz

LEGEND 12" or more on axis