Crown DIFFEROID CM-310A User manual

POLAR
PATTERN
Fig. 2 Frequency Response
(switch set to RISING)
DIFFEROID
(DIFFERENTIAL CARDIOID)
MICROPHONE
Fig. 3 Polar Response
CM-310A
FRONT
REAR
-20
-15
-10
-5
-0
60°
90°
120°
150°180°
210°
240°
270°
300°
0° 30° 330°
500-3500 Hz
250 Hz
10 kHz
20 100 1K 10K
+15
+10
+5
dB 0
-5
-10
-15
-20
-25
-30
-35
0˚, 2 feet
20K
0 ˚, 1/4 inch
*1 pascal = 10 dynes/cm2= 10 microbars = 94 dB SPL.
The Crown®CM-310A Differoid®is a
handheld noise canceling microphone
for singers, sporting events or other ap-
plications with high ambient sound level. It offers
studio-quality sound, yet is rugged enough to
withstand hard use on the road.
The CM-310ASW is the same, but also features a
magnetic reed switch that turns the mic on and off.
The smooth-operating switch operates silently.
Both microphones use Crown’s patented Differoid
technology. Each mic is differential or noise can-
celing, so it rejects sounds that are not close to the
microphone. It also has a cardioid polar pattern, so
it rejects sounds from the rear.
These features give the CM-310A and
CM-310ASW exceptional gain before feedback.
Each mic permits extremely loud monitor levels
before feedback occurs. The mic also rejects un-
wanted background noise. It discriminates against
distant sound sources such as monitor speakers
or instruments. An announcer can sit in the stands
with the audience, with the P.A. loudspeakers play-
ing loudly, and not experience feedback.
The CM-310A and CM-310ASW offer a choice of
FLAT or RISING frequency response. The FLAT po-
sition (Fig. 1) sounds warm and smooth, while the
RISING position (Fig. 2) sounds clear and crisp.
The FLAT position has slightly more gain before
feedback than the RISING position. Announcers
may prefer the RISING position for its extra intelli-
gibility. A DIP switch inside the mic handle sets the
frequency response.
The mic’s outstanding performance is comple-
mented with handsome styling and a comfortable
balance in the hand.
A built-in pop filter suppresses explosive breath
sounds. Handling noise is very low. The unit can
withstand repeated drops and abuse, as well as
extremely loud sound without distortion.
The output of the microphone is balanced, low
impedance, which allows long cable runs without
hum pickup or high-frequency loss. The unit can
be phantom powered from a mixer or other remote
power supply.
Included with the microphone is a convenient car-
rying pouch, the ASA-2 mic stand adapter, and the
WS4 windscreen for outdoor use.
Specifications
Transducer type: Electret condenser.
Frequency response (typical): 80 Hz to 15,000 Hz.
(see Figs. 1 and 2).
Polar pattern: Cardioid. See Fig. 3.
Impedance: 200 ohms balanced. Recommended
minimum load impedance 1000 ohms.
Open circuit sensitivity, typical, close talking: 1.7
mV/Pa* (–55.5 dBV/Pa).
Power sensitivity, typical, close talking: –54.5 dB re
1 mW/Pa*.
Equivalent noise level (self-noise): 21.5 dB SPL
typical (0 dB = 0.0002 dyne/cm2), A-weighted.
S/N Ratio: 72.5 dB at 94 dB SPL.
Maximum SPL for 3% THD: 151 dB SPL with 48V
phantom, 143 dB SPL with 12V phantom.
Operating voltage: Phantom power, 12V to 48V DC,
positive voltage on pins 2 and 3 with respect to pin
1 of output connector.
Polarity: Positive pressure on the diaphragm pro-
duces a positive voltage on pin 2 with respect to
pin 3 of output connector.
Current drain: 1.7 milliamperes.
Cable: None supplied; use 2-conductor shielded
microphone cable.
Connector: 3-pin professional audio connector (XLR
type).
Switches: Internal DIP switch on PC board sets
frequency response to FLAT or RISING. The
CM-310ASW also has a magnetic reed switch in
the handle that turns the mic on and off.
Materials: Rugged aluminum alloy housing, steel
grille.
Finish: Satin black.
Net weight: 7.1 oz. (200 g).
Dimensions: See Fig.4.
Included accessories: Carrying pouch, ASA-2 micro-
phone stand adapter and WS-4 windscreen.
Optional accessories: Crown PH-1A phantom power
supply (1 channel, battery or AC adapter powered).
Replacement parts: Field-replaceable grillescreen is
available from Crown’s Parts Department.
1K 10K 20 100
+15
+10
+5
-5
-10
-15
-20
-25
-30
-35
dB 0
0˚,0 Inches
0˚, 2 Feet
160˚, 2 Feet
Fig. 1 Frequency Response
(switch set to FLAT)
Frequency in Hz
Frequency in Hz
CM-310ASW
• Differoid operation provides extremely high gain
before-feedback and isolation
• Warm, smooth sound
• Low handling noise
• Adjustable frequency response for either music
or announcing applications
• CM-310ASW has a magnetic reed on-off switch
CM-310ASW SWITCH DETAIL
CM-310A
Features

Crown International
1718 W. Mishawaka Rd.
Elkhart, IN 465157-9439
TEL: [phone]
FAX: [phone]FAX
www.crownaudio.com
CM-310ASW
Fig. 4
7.335"
2.020" .840"
Fig. 6
Operating Instructions
Using a 2-conductor shielded microphone cable,
plug the microphone into a mixer mic input with
12 to 48 volts phantom power or use a phantom
power supply. Crown makes a phantom power
supply, model PH-1A (1 channel, battery or AC-
adapter powered). For special applications, you
can make your own phantom supply as shown in
Fig. 5.
Since the microphone cancels sounds that are
not close to the mic, you must talk close to the
microphone with lips touching the grille screen;
talk directly into the front of the microphone (as
in Fig. 6).
To reduce wind noise, place the included foam
windscreen on the microphone. Note: This will
reduce the mic’s noise-canceling ability by about
5 dB.
The switch inside the CM-310A is factory-set to
FLAT for a warm, smooth sound and the most gain
before feedback. You can set the switch to RISING
for a brighter, crisper sound, but this will slightly
reduce the gain before feedback. Announcers may
prefer the RISING position for its extra intelligibil-
ity. The switch inside the CM-310ASW is
factory-set to RISING to enhance articulation.
If you want to change the switch setting, follow
these steps:
You’ll need a small Phillips screwdriver, a needle-
noise pliers and a ball-point pen or pencil.
Fig. 5
2
+
3
1
12
3
18V (TWO 9-V ALKALINE)
MATCH RESISTORS WITHIN 1% (10 OHMS)
TO MIC TO MIXER
MIC INPUT
1:1 XFMR
100mF 25V
1K
CT
TO MIXER
MIC INPUT
TO MIC
18V (TWO 9-V ALKALINE)
1K
+
100mF 25V
+
21
3
1
2
3
+
Fig. 7
RISING FLAT
DIP SWITCH
CM-310ASW
The microphone shall be the Crown model CM-
310ASW Differoid or equivalent. The microphone
shall be a hand-held differential-type condenser
microphone requiring 12 to 48 volts phantom
power. The microphone shall have a 2-position dip
switch for setting the frequency response to flat
or rising high frequencies. The microphone shall
have a magnetic reed switch that turns the micro-
phone on and off.
A smooth frequency response from 80 Hz to 15
kHz shall be obtained, with a uniform off-axis
response. The polar pattern shall be cardioid. The
microphone shall have an open-circuit sensitivity
of 1.7 mV/Pa. The microphone shall accept a 151-
dB SPL input while providing no greater than 3%
THD (open-circuit termination). Equivalent noise
shall be 21.5 dBA typical (0 dB = .0002 dyne/cm2).
The Crown model CM-310ASW microphone is
specified.
Warranty
Crown professional microphones are guaranteed
against malfunction for a period of three years
from date of original purchase. Please refer to the
enclosed full warranty statement for more detail.
Service
If the unit fails to work, first replace or repair the
mic cables and check the power supply. If service
is required, return the microphone in its original
packaging to: Crown Factory Service, 1718 West
Mishawaka Road, Elkhart, Indiana 46517-9439.
A Service Return Authorization (SRA) is required
for product being sent to the factory for service.
An SRA can be completed on line at www.crown-
audio.com/support/factserv.htm. For further assis-
tance or technical support call 800-342-6939.
1. In the handle, unscrew the screw near the con-
nector.
2. Using the pliers, pull on the XLR-connector
pins to pull out the PC board. Caution: Do not
pull so hard that you break the leads going to
the board.
3. Locate the DIP switch shown in Fig. 7. Using
the ball-point pen or pencil, set the switches to
the FLAT or RISING position shown in Fig. 7. FLAT
gives the frequency response shown in Fig. 1.
RISING gives the frequency response shown in
Fig. 2.
Architects’ and Engineers’ Specifications
CM-310A
The microphone shall be the Crown model CM-
310A Differoid or equivalent. The microphone
shall be a hand-held differential-type condenser
microphone requiring 12 to 48 volts phantom
power. The microphone shall have a 2-position dip
switch for setting the frequency response to flat or
rising high frequencies.
A smooth frequency response from 80 Hz to 15
kHz shall be obtained, with a uniform off-axis
response. The polar pattern shall be cardioid. The
microphone shall have an open-circuit sensitivity
of 1.7 mV/Pa. The microphone shall accept a 151-
dB SPL input while providing no greater than 3%
THD (open-circuit termination). Equivalent noise
shall be 21.5 dBA typical (0 dB = .0002 dyne/cm2).
The Crown model CM-310A microphone is speci-
fied.
12/05 136826-2
CM-310A
©2005 Crown Audio®, Inc. Specifications subject to
change without prior notiece. Latest information available
at www.crownaudio.com. Crown, Crown Audio and Dif-
feroid are registered trademarks of Crown International.