CM311 A CM311 AESH CM311 L
Designed for touring and live-sound applications, the AKG/Crown CM311 is a rugged head-worn microphone
with unequalled performance. It sounds like the best handheld microphones - full,
clear, and distortion-free, even with the loudest singers.
The CM311 is the latest version of the
AKG/Crown’s proprietary Differoid® technology. Its cardioid pickup pattern rejects sounds from the rear, such as floor monitors. Its noise-cancelling ability rejects sounds at a distance, such as instruments on stage and crowd noise. This results in the CM311 having outstanding gain-before- feedback and isolation.
Lightweight and comfortable, the mic’s headband and boom adjust to fit any singer. An included pop filter 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.
Three models are available: CM311 A, CM311 AESH and CM311 L. The CM311 A is powered by a 9 V 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 CM311 AESH has a T4AF connector, allowing you to connect with Shure® wireless systems. The L version offers a 3-pin mini XLR output, which fits all AKG wireless body-pack transmitters.
How to adjust for best fit and to prevent boom bounce
Note: To get the maximum performance out of this microphone, take the time to adjust it to fit correctly.
For best results, the CM311 A MUST be custom fitted 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 fit 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.
DIFFEROID® HEAD-WORN
CONDENSER MICROPHONE
Specifications
Transducer type: Electret condenser.
Frequency response (typical): 50 Hz to 17,000 Hz (see Fig. 1).
Polar pattern: Cardioid (see Fig. 2).
Impedance: CM311 A, 75 ohms balanced. CM311 AESH and CM311 L, 6 kilohms unbalanced.
Recommended load impedance: CM311 A, 1000 ohms or greater. CM311 AESH and CM311 L, 10 kilohms.
Open-circuit sensitivity, typical, close-talking:
CM311 A, 4 mV/Pa* (–48 dB re 1V/Pa), CM311 AESH and CM311 L, 1.25 mV/Pa
(–58 dB re 1V/Pa).
Power sensitivity, typical, close-talking:
CM311 A: – 42.5 dB re 1 mW/Pa*, CM311 AESH and CM311 L: –71.5 dB re 1 mW/Pa.
Equivalent noise level (self noise): 26 dB SPL typical (0 dB = 0.0002 dyne/cm2),
A-weighted.
S/N ratio: 68 dB at 94 dB SPL.
Maximum SPL: CM311 A, 148 dB SPL produces 3% THD. CM311 AESH and CM311 L, 140 dB SPL with 3V DC, 148 dB SPL with 9V DC.
Operating voltage: CM311 A, 9 V DC internal alkaline battery or 18-48 V phantom power. CM311 AESH and CM311 L, 3-9 V DC from the transmitter’s battery.
Polarity: Positive pressure on diaphragm produces positive voltage on CM311 A XLR pin 2 with respect to pin 3, and on CM 311 AESH and CM311 L shield with respect to white lead.
Current drain: CM311 A, 6.5 mA nominal. CM311 AESH and CM311 L, 0.27 mA nominal.
Off-attenuation: 70 dB.
Out put connectors: CM311 A, 3-pin pro audio (XLR type). CM311 AESH, TA4F for Shure® w ireless systems. CM311 L, 3-pin mini XLR.
Mat erials: High-impact plastic mic housing, b rass boom, steel wire headband, high- i mpact plastic and steel battery pack.
Finish: Satin black.
Net weight: Head-worn mic, 2.1 oz (61 g).
C M311 A belt pack and battery, 6.1 oz (173g).
Dim ensions: |
Headband |
5.5-inch |
(13.97 cm) |
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d iameter, adjustable. Boom approximately |
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7 -inch (17.78 cm) x 3-inch (7.62 cm). |
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S ee Figs. 3 and 4. |
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Included |
accessories: |
Microphone |
carrying |
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c ase, WS-6 foam pop filter, clothing clip. |
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Optional |
accessories: |
PH-4B phantom power |
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s upply |
(4 channels, |
AC powered). PH-1A |
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p hantom power supply (1 channel, battery or |
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A C-adapter |
powered). |
WS-14 |
accessory |
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w indscreen. |
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*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.
Battery life: CM311 A, 85 hours. CM311 AESH and CM311 L, approximately equal to transmitter battery life.
Fig. 1
Frequency Response
+15 |
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+10 |
0˚, 1.375" |
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+5 |
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dB 0 |
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-5 |
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-10 |
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-15 |
0˚ 2' |
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-20 |
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-25 |
120˚, 2' |
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-30 |
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-35 |
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20 |
100 |
1K |
10K |
20K |
Frequency in Hz
Fig. 2
Polar Response
330˚ |
0˚ |
30˚ |
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FRONT |
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300˚ |
-0 |
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-5 |
60˚ |
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-10 |
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-15 |
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-20 |
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270˚ |
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90˚ |
240˚ |
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120˚ |
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1000 Hz |
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300 Hz |
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6000 Hz |
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REAR |
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210˚ |
180˚ |
150˚ |
Fig. 3 |
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Fig. 4 |
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MIC
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