POLAR
PATTERN
MINIATURE SUPERCARDIOID
CONDENSER MICROPHONE
CM-30
CM-30W
he Crown® CM-30 is a professional-
quality, supercardioid condenser micro-
phone designed for inconspicuous miking
T
of a choir, orchestra or stage. The mic cable
connects to the electronics/faceplate which fits
a standard electrical outlet box. The CM-30 can
also hang over conference tables or discussion
groups for inconspicuous isolated miking.
Features
• Small and inconspicuous
• Hanger allows position adjustment
• Electronics mount in a standard electrical
outlet box
• Ideal for picking up choirs
• Supercardioid polar pattern aids gain-before-
feedback and rejects background noise
Because of its supercardioid pickup pattern, the
CM-30 rejects background noise and room re-
verberation, and improves gain-before-feedback
more than a cardioid microphone.
Specifications
Type: Unidirectional condenser.
Transducer: Electret condenser.
Frequency Response (typical): 40 Hz to 20,000 Hz.
See Fig. 1.
The CM-30 has a smooth, wide-range
Frequency Response
Fig. 1
frequency response for natural reproduction of
the singing voice, organ or other musical instru-
ments. Extreme low frequencies are filtered out
to reduce pickup of room rumble.
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.
The microphone output is balanced, low imped-
ance. It is protected against static and
radio frequency interference. A built-in remov-
able hanger allows easy position adjustment by
bending the lower portion of the hanger. The
CM-30 requires 12-48V phantom power. The
CM-30 is black; the CM-30W is white.
Frequency in Hz
Equivalent Noise Level: 28 dB SPL typical
Operating Instructions
(0 dB = 0.0002 dyne/cm2), A-weighted.
S/N Ratio: 66 dB at 94 dB SPL.
Maximum Sound Pressure Level: 120 dB SPL
produces 3% THD.
Input Connectors: Screw terminals.
Output Connectors: Screw terminals.
Operating Voltage: Phantom power, 12 to 48 volts
DC, positive voltage on pins 2 and 3 with respect
to pin 1 of output terminal.
Current drain: 4.5 milliamperes.
Materials: Brass housing, steel faceplate.
Finish: Black (CM-30) or white (CM-30W) micro-
phone, white faceplate.
Weight (microphone and cable): 4 ounces (113
grams).
Weight (microphone, cable and circuit): 7.5
ounces (212 grams).
Cable: Black (CM-30) or white (CM-30W), 30-ft
(9.15-m) 2-conductor shielded 0.1-in. (0.254-
cm) diameter cable from microphone to electron-
ics; none supplied for electronics output. Use
2-conductor shielded microphone cable.
The CM-30 consists of the microphone, at-
tached 30-ft (9.5-m) cable, and associated elec-
tronics. The electronics PC board is mounted
to the rectangular electrical plate (provided) as
shown in Fig. 4. The mating electrical backbox
should be installed at the mounting location.
Input and output screw terminals eliminate the
need for cable connectors. The provided strain
relief acts as a cable clamp when securely
tightened.
Fig. 2
Polar Response
Recommended microphone placement for
sound reinforcement is shown in Figs. 5a and
5b. 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.
Architects’ and Engineers’ Specifications
The microphone shall be the Crown CM-30. It
shall be a professional-quality supercardioid
condenser microphone designed for incon-
spicuous miking of a choir or other large musi-
cal ensembles. It shall be hung from the ceiling,
where its cable shall connect to electronics
installed in a standard electrical outlet box.
Dimensions: See Fig. 3 on reverse side.
Included Accessories: WS-5 windscreen (black or
white).
Frequency response shall be 40 Hz to 20,000
Hz. Extreme low frequencies shall be filtered out
to reduce pickup of room rumble. Open-circuit
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.
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