Audio-Technica AT933RX/ML - Manual

Description

The AT933Rx/ML is a wide-range miniature

condenser microphone with a MicroLine



polar

pattern. It is designed for quality sound reinforce-
ment, professional recording, television, and
other demanding sound pickup applications. The
AT933Rx/ML 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 /ML.

Installation and Operation

The combination of small size and excellent

response makes the AT933Rx /ML ideal for
suspension over choirs, instrumental groups or
theater stages. A uniform 90

°

angle of acceptance

provides well - balanced pickup over a narrow
area. 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 1.5 times

the distance to the closest performer. If additional
mics are needed for wide sources, they should
not be closer together laterally than 1.5 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). Adjust the vertical angle by changing
the number of loops the cable passes through in
the steel hanger.

The provided foam windscreen simply slips

over the MicroLine element, effectively reducing
noise from wind or ventilation air currents.

AT933Rx/ML

MicroLine



Miniature
Condenser
Hanging
Microphone

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 shor ten the cable, remove the three

screws from the base of the power module and
slide the outer case up the cable to reveal the cir-
cuit 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 cer tain
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, temper-
ature 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.

LESS THAN

2 TIMES “X”

DIST

ANCE “X”

90

°

ANGLE OF
ACCEPTANCE

MIC A

1.5 TIMES

DISTANCE “X”

MIC B

9 0

°

9 0

°

Figure 1

Figure 2

Frequency Response

(Typical)

LEGEND

Roll-off

12" or more on axis (flat)

Frequency in Hertz

Response in dB

10 dB

20k

10k

5k

2k

1k

500

200

100

50

Figure 3

Figure 4

Shield strands,
fully twisted

Yellow-Yellow

Red-Red

1

/

8

" strip reds

and yellows

1

/

2

"

1"

Terminal
screws

Case
grounding
contact

Yellow-Yellow

Red-Red

Shield

PC board

switch side

S

Y

R