Crown Audio CM-311AE Dépliant

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CM-311A
CM-311AE
DIFFEROID HEAD-WORN
CONDENSER MICROPHONE
D
esigned for touring and live-sound applica-
    tions,  the  Crown
®
 CM-311A is a rugged 
    head-worn  microphone  with  unequalled 
performance. It sounds like the best handheld micro-
phones—full, clear, and distortion-free, even with the 
loudest singers.
The CM-311A is the latest version of the Crown’s 
proprietary Differoid
®
 technology. Its cardioid pickup 
pattern rejects sounds from the rear, such as fl oor 
monitors. Its noise-canceling ability rejects sounds at 
a distance, such as instruments on stage and crowd 
noise. This results in the CM-311A having outstand-
ing gain-before-feedback and isolation.
Lightweight and comfortable, the mic’s headband and 
boom adjust to fi t any singer. An included pop fi lter 
greatly reduces breath noise and pops. Because of 
the boom’s unique behind-the-ear design, it does not 
cover up the singer’s face.
Two models are available: CM-311A and CM-311AE. 
The CM-311A is powered by a 9V battery or phantom 
power. It has a battery belt pack with an on/off switch, 
a programmable mic on/off switch, and a “Mic On” 
LED. The CM-311AE is a pig-tail version allowing you 
to connect it to most wireless transmitters.
NOTE:  Putting an XLR connector on the CM-311AE 
and connecting to a mic input with phantom power 
WILL damage the mic element. For wired applica-
tions, use the CM-311A.
How to adjust for best fi t and to prevent boom 
bounce
Note:  To get the maximum performance out of this 
microphone, take the time to adjust it to fi t correctly.
For best results, the CM-311A MUST be custom fi tted 
to a single user’s head. This simple procedure takes 
only a few minutes. Please refer to Fig. 5 and locate 
the parts described.
1. If the microphone is for yourself, we suggest that 
you use a mirror to double check the fi t as you make 
adjustments.
2. Loosen (just a little) the thumbscrew located on 
the outside of the foam block, part way back on the 
boom. This allows the boom to slide in and out, and 
to rotate left and right.
3. Now bend the headband wire to fi t your head. Put 
the foam-block wire behind your ear. Then you can 
bend the earpieces to fi t snugly around your ears. 
The back of the headband should fi t fi rmly against the 
back of your neck.
Specifi cations
Transducer type: Electret condenser.
Frequency response (typical): 50 Hz to 17,000 Hz 
(see Fig. 1).
Polar pattern: Cardioid (see Fig. 2).
Impedance: CM-311A, 75 ohms balanced. CM-311AE, 
6 kilohms unbalanced. 
Recommended load impedance: CM-311A, 1000 
ohms or greater. CM-311AE, 10 kilohms. 
Open-circuit sensitivity, typical, close-talking: CM-
311A, 4 mV/Pa* (–48 dB re  1V/Pa), CM-311AE, 
1.25 mV/Pa (–58 dB re 1V/Pa).
Power sensitivity, typical, close-talking:   CM-311A: 
–42.5 dB re 1 mW/Pa*, CM-311AE: –71.5 dB re 1 
mW/Pa.
Equivalent noise level (self noise): 26 dB  SPL typi-
cal (0 dB = 0.0002 dyne/cm
2
), A-weighted.
S/N ratio: 68 dB at 94 dB SPL.
Maximum SPL: CM-311A, 148 dB SPL produces 3% 
THD. CM-311AE, 140 dB SPL with 3V DC, 148 dB 
SPL with 9V DC.
Operating voltage: CM-311A, 9V DC internal alkaline 
battery or 18-48V phantom power. CM-311AE, 
3–9V DC from the transmitter’s battery.
Polarity: Positive pressure on diaphragm produces 
positive voltage on CM-311A XLR pin 2 with 
respect to pin 3, and on CM-311AE shield with 
respect to white lead.
Current drain: CM-311A, 6.5 mA nominal.  
CM-311AE, 0.27 mA nominal.
Battery life: CM-311A, 85 hours. CM-311AE, approxi-
mately equal to transmitter battery life.
Operating temperature range:  –10° to +50° C, or 
–14° to +122° F. 
Off-attenuation:  70 dB.
Output connectors: CM-311A, 3-pin pro audio (XLR 
type). CM-311AE, supply your own to match your 
transmitter.
Cables (CM-311A): 2-conductor shielded, unbalanced 
cable, 42-inches (106.68 cm) from headband to 
battery pack. Use 2-conductor shielded mic cable 
(not included) between XLR connector and mixer 
mic input.
Cable (CM-311AE): In-line with this cable is a small 
circuit module that equalizes the microphone 
signal. Cable is 42-inches (106.68 cm) long from 
headband to module, 12-inches (30.48 cm) from 
module to cable end. 2-conductor shielded unbal-
anced cable, unterminated.
Materials: High-impact plastic mic housing, brass 
boom, steel wire headband, high-impact plastic and 
steel battery pack.
Finish: Satin black.
Net weight: Head-worn mic, 2.1 oz (61 g). CM-311A 
belt pack and battery, 6.1 oz (173g).
Dimensions: Headband 5.5-in. (13.97 cm) diameter, 
adjustable. Boom approximately 7 in. (17.78 cm) x 
3 in. (7.62 cm). See Figs. 3 and 4.
Included accessories: Microphone carrying case, 
WS-6 foam pop fi lter, clothing clip.
Frequency in Hz
Frequency Response
Fig. 2
Fig. 1
MIC
Fig. 3
Polar Response
  POLAR 
PATTERN
Features
•  Full, clear, distortion-free sound
•  Outstanding gain-before-feedback and isolation
•  CM-311A has battery/phantom belt pack
•  CM-311AE connects to most wireless transmitters
Optional accessories: PH-1A phantom power 
supply (1 channel, AC-adapter powered). WS-
14 accessory windscreen.
*1 pascal = 10 dynes/cm
2
 = 10 microbars = 94 dB