Crown Audio CM-31, CM-31W User Manual

POLAR
PATTERN

CM-31
CM-31W

he Crown® CM-31 is a professional­ quality, supercardioid condenser micro­ phone designed for inconspicuous miking

T

of a choir, orchestra or stage. It can also hang
over conference tables or discussion groups for

inconspicuous isolated miking.

The CM-31 consists of two parts: the micro­phone with a permanently attached 30-foot
(9.15-m) cable and the cylindrical electronics
power module.

The mic cable connects to the power module,
which adapts the microphone for phantom
powering and includes a low-cut switch. Cable
connection is via miniature 3-pin connectors.
The power module output is balanced, low
impedance. It is protected against static and
radio-frequency interference.

The CM-31 has a smooth, wide-range frequency
response for natural reproduction of the singing
voice, organ or other musical instruments. Ex­treme low frequencies are fi ltered out to reduce
pickup of room rumble.

The microphone has a built-in removable
hanger which allows easy position adjustment.
The CM-31 microphone and cable are black; the
CM-31W microphone and cable are white.

Operating Instructions

The power module supplied has been matched
to the microphone. For best performance do not
intermix microphones and modules.

Plug the microphone into the electronics power
module. Run a 2-conductor shielded mic cable
(not supplied) from your mixer to the power
module, and plug it in.

Experiment with microphone placement before
permanently installing the power module. A
suggested placement for choir sound reinforce­ment is shown in Figs. 4a and 4b. For recording
or broadcast, you might want to place the
microphone a few feet farther away to pick up
more room acoustics. Bend the wire hanger to
achieve the desired pickup angle.

If rumble from trucks or air-conditioning is
excessive, switch in the low-cut fi lter on the
power module. The low-cut position (
toward the microphone.

After fi nding the desired microphone position,
install the power module in one of three ways:

• Install the power module in the ceiling (Fig.

6). Pull up the mic cable until the mic is at the
desired height, then knot the cable.

• Clamp the power module to a beam overhead
(Fig. 7).

• Tape the power module to the fl oor.

) is

MINIATURE CONDENSER
HANGING MICROPHONE

Features

• Ideal for picking up choirs

• Supercardioid polar pattern aids gain-before­feedback and rejects background noise

Specifi cations

Type: Unidirectional condenser.
Transducer: Electret condenser.
Frequency Response (typical): 40 Hz to 20,000 Hz

(see Fig. 1).

Polar Pattern: Supercardioid (see Fig. 2).
Impedance: 150 ohms, balanced. Recommended

minimum load impedance 1000 ohms.

Open Circuit Sensitivity: 10 mV/Pa* (–40 dB re 1

volt/Pa).

Power Sensitivity: –37.5 dB re 1 mW/Pa.
Equivalent Noise Level: 28 dB SPL typical (0 dB =

.0002 dyne/cm

S/N Ratio: 66 dB at 94 dB SPL.
Maximum Sound Pressure Level: 120 dB SPL

produces 3% THD.

Mic-Cable Connector: TA3F (mini XLR-type).
Power Module Connector (input): TB3M (mini XLR-

type). See Fig. 3.

Power Module Connector (output): 3-pin male XLR-

type.

Power Module Switch: Flat/low-cut.
Operating Voltage: Phantom power, 12 to 48 volts

DC, positive voltage on pins 2 and 3 with respect to
pin 1 of output connector.

Materials: Brass housing, steel power module hous-

ing.

Finish: Black (CM-31) or white (CM-31W).
Weight (microphone and cable): 4 ounces (113

grams).

Weight (microphone, cable and power module): 9.5

ounces (269 grams).

Cable: Black (CM-31) or white (CM-31W), 30' (9.15-

m) 2-conductor shielded 0.1" (.254-cm) diameter
cable from microphone to electronics; none
supplied for electronics output. Use 2-conductor
shielded microphone cable.

Dimensions: See Fig. 5 on reverse side.
Included Accessories: WS5 black foam windscreen

for CM-31, WS5W white foam windscreen for
CM-31W.

Optional Accessories: Crown PH-1A phantom power

supply (1 channel, battery or AC adaptor powered).

*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.

2

), A-weighted.

• Small and inconspicuous

• Hanger allows position adjustment

• XLR connector with built-in electronics

Fig. 1

Fig. 2

Fig. 3

Frequency Response

Frequency in Hz

Polar Response

Architects’ and Engineers’ Specifi cations

The microphone shall be the Crown CM-31.
It shall be a professional-quality supercar­dioid condenser microphone designed for
inconspicuous miking of a choir or other large
musical ensembles. It can be hung from the
ceiling, where its cable shall connect to a cylin­drical electronics power module that adapts the
microphone for phantom powering.

Frequency response shall be 40 Hz to 20,000
Hz. Extreme low frequencies shall be fi ltered out
to reduce pickup of room rumble. The power
module shall have fl at/low-cut switch. Open­circuit sensitivity shall be 10 mV/Pa. Equivalent
noise level shall be 28 dBA SPL typical; SPL

Fig. 4a

for 3% THD shall be 120 dB. The microphone
output shall be balanced, low impedance, with
RFI and static protection.

A built-in removable hanger shall allow posi­tion adjustment. The mic-cable connector shall
be a TA3F. The power module input connector
shall be a TB3M and the power module out­put connector shall be a 3-pin male XLR-type.
Operating voltage shall be standard phantom
power, 12 to 48 volts DC, positive voltage on
pins 2 and 3 with respect to pin 1 of output con­nector. Finish shall be black (CM-31) or white
(CM-31W). The cable from mic to electronics
shall be 30-foot (9.15-m) 2-conductor shielded.
The Crown CM-31 is specifi ed.

Fig. 6

Fig. 7

Use the clamp and screw provided to mount the
CM-31/CM-31W power module onto the ceiling,
a wooden beam, or beneath a lectern/table.

CM-31
CM-31W

Warranty

Crown professional microphones are guaran­teed unconditionally against malfunction from
any cause for a period of three years from date
of original purchase. See enclosed warranty
sheet for additional information.

Service

If the microphone does not function properly,
replace or repair mic cables and connectors,
check the power supply.

If you determine the microphone product(s)
is defective, return the complete product
mic and interface) in its original package to:

Crown Factory Service, 1718 W. Mishawaka
Road, Elkhart, IN 46517-9439.

Return Authorization (SRA) is required for
product being sent to the factory for ser­vice. An SRA can be completed on line at
www.crownaudio.com/support/factserv.htm.

For further assistance or technical support call

800-342-6939.

The mic and electronics are a matched pair.
Do not separate them. For service send them
both in.

A Service

Fig. 4b

Fig. 5

Crown International, Inc.
1718 W. Mishawaka Rd.
Elkhart, IN 46517-9439
TEL: [phone]
FAX: [phone]FAX
www.crownaudio.com

©

2005 Crown Audio®, Inc.
Specifi cations subject to change without prior notice.
Crown and Crown Audio are registered trademarks of
Crown International, Inc.

11/05 125114-4