AT933Rx /C
Cardioid
Description
The AT933Rx/C is a wide-range miniature condenser microphone with a cardioid polar pattern. It is designed for quality sound reinforcement, professional recording, television, and other demanding sound pickup applications. The
AT933Rx /C is furnished with a vinyl-coated steel hanger adapter that allows it to be adjusted for correct positioning.
The microphone features a 50' (15.2 m) permanently-attached miniature cable. Its free end connects to the provided AT8533x power module via internal solderless screw terminals for simple cable-length adjustment in the field. It can be powered from any external 9V to 52V DC phantom power supply. A recessed switch in the power module permits choice of flat response or low-frequency roll-off to help control undesired ambient noise.
Four additional interchangeable elements are available to permit selection of angle of acceptance from 90
°
to 360
°
.
The microphone is enclosed in a rugged housing with a low-reflectance black finish. It is also available in white as the AT933RWx/C.
Installation and Operation
The combination of small size and excellent response makes the AT933Rx/C 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).
Width of pickup is approximately three times the distance to the closest performer. If additional 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 the microphone in the proper direction, twist the housing slightly in its wire holder (clockwise rotation moves the microphone to the right; counterclockwise rotation moves it to the left).
The provided foam windscreen simply slips over the head of the microphone, effectively reducing noise from wind or ventilation air currents.
Output is low impedance balanced. The output connector of the power module mates with
XLRF-type cable 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.
To shorten the cable, remove the three screws from the base of the power module and slide the outer case up the cable to reveal the circuit board and screw terminals. Loosen the three terminal screws and remove the cable from the module. Next, slide the case off the cable, cut the cable to the desired length (allowing a few extra inches) and slide the case back onto the cable.
Tie a single knot in the cable about two inches from the cut end. Following Figure 3, cut the cable off 1" down from the top of the knot and carefully remove 1 /
2
" of the outer jacket.
Strip the mic cable wires and attach them to their respective terminals (Fig. 4).
Make certain that the terminals are clamped on the conductors, not on the insulation, and that there are no loose strands of wire which might touch other terminals. Replace the case, being certain that it goes over the case grounding contact and that the roll-off switch is accessible. Finish by replacing the three base screws and testing for proper operation.
While a modern condenser microphone is not unduly sensitive to the environment, temperature extremes can be harmful. 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 (Typical)
LEGEND
50 100 200 500 1k
Frequency in Hertz
2k
12" or more on axis (flat)
Roll-off
5k 10k 20k
10 dB
LESS THAN
DIST
ANCE “X”
2 TIMES “X”
120 °
ANGLE OF
ACCEPTANCE
Figure 1
1"
1 / 2 "
120 °
MIC A
3 TIMES
DISTANCE “X”
MIC B
120 °
Shield strands, fully twisted
Figure 2 Figure 3
Terminal screws
Case grounding contact
Shield
Yellow-Yellow
Red-Red
1 /
8
" strip reds and yellows
S Y
PC board switch side
R
Figure 4
Yellow-Yellow
Red-Red
Miniature
Condenser
Hanging
Microphone
AT933Rx /C
AT933Rx/C Specifications †
Element
Polar Pattern
Frequency Response
Low-frequency Roll-off
Open Circuit Sensitivity
Impedance
Maximum Input Sound Level
Dynamic Range (Typical)
Signal-to-noise Ratio 1
Switch
Phantom Power Requirements
Weight
Microphone
Power Module
Dimensions
Microphone
Power Module
Output Connector (Power Module)
Cable
Accessories Furnished (AT933Rx/C)
(AT933RWx/C)
(Both)
Optional Interchangeable
Elements
Fixed-charge back plate permanently polarized condenser
Cardioid (Unidirectional)
40-20,000 Hz
150 Hz, 6 dB/octave
– 43 dB (7.0 mV) re 1V at 1 Pa*
200 ohms (1000 ohms without power module)
138 dB SPL, 1 kHz at 1% T.H.D.
111 dB, 1 kHz at Max SPL
67 dB, 1 kHz at 1 Pa*
Flat response, low-roll-off (recessed)
9-52V DC, 2 mA typical
0.4 oz (10 grams)
2.1 oz (60 grams)
1.38" (35.0 mm) long, 0.48" (12.2 mm) head diameter
3.58" (91.0 mm) long, 0.83" (21.0 mm) diameter
Integral 3-pin XLRM-type
50' (15.2 m) long (permanently attached to microphone),
0.13" (3.2 mm) diameter, 2-conductor, shielded cable; free end attaches to screw terminals in power module
AT8102 two-stage foam windscreen;
AT8451 steel hanger
AT8102WH two-stage foam windscreen;
AT8451WH steel hanger
AT8533x power module; element adapter (for C/H/O/SC elements)
AT853H-ELE hypercardioid (100
°
)
AT853ML-ELE MicroLine
(90
°
)
AT853O-ELE omnidirectional (360
°
)
AT853SC-ELE subcardioid (170
°
)
† In the interest of standards development, A.T.U.S. offers full details on its test methods to other industry professionals on request.
* 1 Pascal = 10 dynes/cm 2 = 10 microbars = 94 dB SPL
1 Typical, A-weighted, using Audio Precision System One.
Dimensions
0.48"
12.2 mm
1.38"
35.0 mm
50
15.2 m
0.13"
3.2 mm
3.58"
91.0 mm
0.83"
21.0 mm
270
300
240
330
Polar Pattern
0
30
LEGEND
200 Hz
1 kHz
5 kHz
8 kHz
210 150
180
SCALE IS 5 DECIBELS PER DIVISION
60
120
90
Architects and Engineers Specifications
The microphone shall be a fixed-charge condenser with a cardioid polar pattern and a frequency response of 40 Hz to 20,000 Hz. It shall be capable of accepting optional interchangeable elements for additional polar patterns. It shall operate from an external 9V to 52V DC phantom power source. Nominal open-circuit output voltage with the included power module shall be 7.0 mV at 1 kHz,
1 Pascal. Output shall be low impedance balanced
(200 ohms).
The microphone shall have a permanentlyattached 50' (15.2 m) miniature cable with a pigtail output. The pigtail output shall connect to a power module via internal solderless screw terminals. The power module shall include a switch for low-frequency roll-off and shall terminate in a 3-pin XLRM-type output connector.
The microphone shall be mountable in an included steel hanger that allows permanent overhead installation for pickup of dialogue, orchestras and choirs. The microphone shall be 1.38" (35.0 mm) long with a head diameter of 0.48" (12.2 mm). The microphone weight shall be 0.4 oz (10 grams) without cable. The microphone case, cable and steel hanger shall be black [white].
The Audio-Technica AT933Rx/C
[AT933RWx/C] is specified.
One -Year Limited Warranty
Audio -Technica microphones and accessories purchased in the U.S.A. are warranted for one year from date of purchase by Audio-Technica U.S., Inc. (A.T.U.S.) to be free of defects in materials and workmanship. In event of such defect, product will be repaired promptly without charge or, at our option, replaced with a new product of equal or superior value if delivered to A.T.U.S. or an Authorized Service Center, prepaid, together with the sales slip or other proof of purchase date. Prior approval from A.T.U.S. is required for return. This warranty excludes defects due to normal wear, abuse, shipping damage, or failure to use product in accordance with instructions. This warranty is void in the event of unauthorized repair or modification.
For return approval and shipping information, contact the Service Department, Audio-Technica U.S., Inc.,
1221 Commerce Drive, Stow, Ohio 44224.
Except to the extent precluded by applicable state law, A.T.U.S. will have no liability for any consequential, incidental, or special damages; any warranty of merchantability or fitness for particular purpose expires when this warranty expires.
This warranty gives you specific legal rights, and you may have other rights which vary from state to state.
Outside the U.S.A., please contact your local dealer for warranty details.
Audio -Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England
Form No. 0309-9510- 01-B/W P50890-01
1999 Audio -Technica U.S., Inc.
Printed in U.S.A.
