The CM-311A offers Differoid performance in a comfortable headworn package. The CM-311A is designed to meet the most demanding touring sound applications, with its electret condenser capsule providing full, clear, and distortion-free sound. Gain-before-feedback and isolation are exceptional. Lightweight, rugged, and comfortable, the headband and mic boom are adjustable to any vocalist. CM-311A includes battery/phantom powered belt pack.
For Wired Applications
Designed for touring and live-sound applications, the Crown(R) CM-311A is a rugged head-worn microphone with unequaled performance. It sounds like the best handheld microphones -- full, clear, and distortion-free, even with the loudest singers.
The CM-311A is the latest version of the Crown's proprietary Differoid(R) technology. Its cardioid pickup pattern rejects sounds from the rear, such as floor 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 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.
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.
To get the maximum performance out of this microphone, take the time to adjust it to fit correctly. For best results, the CM-311A MUST be custom fitted to a single user's head.
Technical Info
This is NOT a wireless system. It is a headworn microphone with belt pack. The belt pack connects to an XLR cable from your mixer, preamp, etc.
Transducer Type: Electret condenser.
Frequency Response (typical): 50 Hz to 17,000 Hz
Polar Pattern: Cardioid
Impedance: 75 ohms balanced
Recommended Load Impedance: 1000 ohms or greater
Open-Circuit Sensitivity, typical, close-talking: 4 mV/Pa* (+48 dB re 1V/Pa)
Power Sensitivity, typical, close-talking: +42.5 dB re 1 mW/Pa*
*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL
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: 148 dB SPL produces 3% THD
Operating Voltage: 9V DC internal alkaline battery or 18-48V phantom power
Polarity: Positive pressure on diaphragm produces positive voltage on CM-311A XLR pin 2 with respect to pin 3
Current Drain: 6.5 mA nominal
Battery Life: 85 hours
Off-Attenuation: 70 dB
Output Connectors: 3-pin pro audio (XLR type)
Cables: 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.
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)
Included Accessories: Microphone carrying case, WS-6 foam pop filter, clothing clip
Optional Accessories: PH-4B phantom power supply (4 channels, AC powered). PH-1A phantom power supply (1 channel, battery or Acadapter powered). WS-14 accessory windscreen
***Note: Users with petite heads may have to cut off extra headband material to get the headband to fit properly.
Personal use items that are used at your mouth or in your ear cannot be returned once opened due to health laws. This includes all microphones, guitar talk boxes, ear plugs, and in-ear earphones. 
