The Crown® CM-312A is a rugged, lightweight head-worn microphone designed for aerobics, live entertainment, and sports broadcasting. It is intended for applications that require a light, inconspicuous mic.

Because the microphone is to the side of the mouth, breath pops are eliminated. The sound of the CM-312A can be tailored to taste by moving the microphone closer or farther from the corner of the mouth.

The CM-312A sounds like the best handheld microphones. Its hypercardioid pickup pattern reduces feedback and aids isolation. In difficult situations, the Crown CM-311A headworn mic is recommended because it picks up even less feedback and leakage than the CM-312A.

Designed for comfort, the headband fits behind the head and disappears in use. Both the headband and boom adjust to fit any head. Because of the boom’s unique behind-the-ear design, it does not cover up theuser’s face.

Two models are available: CM-312A and CM-312AE. The CM-312A is powered by a 9V battery or phantom power. It has a battery belt pack with a battery on/off switch, a programmable mic on/off switch, and a “Mic On” LED. The CM-312AE has no connector; you connect it to a wireless transmitter of your choice. Crown has some versions of the CM-312AE pre-wired with connectors for various wireless systems, such as the CM-312AESH for Shure wireless systems. Please ask your local dealer or Crown Technical Support for more information.

Specifications:

• Transducer type: Electret condenser.
• Frequency response (typical): 50 Hz to 17,000 Hz
• Polar pattern: Hypercardioid
• Impedance: CM-312A, 75 ohms balanced. CM-312AE, 6 kilohms unbalanced.
• Recommended load impedance: CM-312A, 1000 ohms or greater. CM-312AE, 10 kilohms.
• Open-circuit sensitivity, typical, close-talking:
  • CM-312A, 3.8 mV/Pa* (–48.5 dB re 1V/Pa).
  • CM-312AE, 2.9 mV/Pa (–51 dB re 1V/Pa).
• Power sensitivity, typical, close-talking:
  • CM-312A: –43 dB re 1 mW/Pa*.
  • CM-312AE: –65 dB re 1 mW/Pa.
• Equivalent noise level (self noise): 31 dB SPL typical (0 dB = 0.0002 dyne/cm2), A-weighted.
• S/N ratio: 63 dB at 94 dB SPL.
• Maximum SPL: 148 dB SPL produces 3% THD.
• Operating voltage: CM-312A, 9V DC internal alkaline battery or 18-48V phantom power. CM-312AE, 3–9V DC from the transmitter’s battery.
• Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3, and onCM-312AE white lead with respect to shield.
• Current drain:
  • CM-312A, 6 mA nominal.
  • CM-312AE, 0.27 mA nominal.
• Battery life:
  • CM-312A, 90 hours.
  • CM-312AE, approximately equal to transmitter battery life.
• Off-attenuation: 70 dB @ 1kHz.
• Output connectors: CM-312A, 3-pin pro audio (XLR type). CM-312AE, supply your own to match your transmitter.
• Cables:
  • CM-312A: 2-conductor shielded, unbalanced cable, 3-feet (0.915-m) from mic capsule to battery pack. Use 2-conductor shielded mic cable (not included) between XLR connector and mixer mic input.
  • CM-312AE: 45-inches long (1.144-m), 2-conductor shielded unbalanced cable, unterminated. In-line with this cable is a small circuit module that equalizes the microphone signal.
• Materials: High-impact plastic and PVC mic housing, brass boom, steel wire headband, high-impact plasticand steel battery pack.
• Finish: Satin black.
• Net weight:
  • Head-worn mic, 1.5 oz (43 g).
  • CM-312A belt pack and battery, 6.1 oz (173 g).
• Dimensions:
  • Headband 5.5 in. (13.97 cm) diameter, adjustable.
  • Boom approximately 5.75 in. (14.61 cm).
• Included accessories: Microphone carrying case, WS-7 foam pop filter and clothing clip for aerobics.
• Optional accessories: PH-1A phantom power supply (1 channel, battery or AC-adapter powered).

* 1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.