The Crown® CM-310A Differoid® is a handheld noise canceling microphone for singers, sporting events or other applications with high ambient sound level. It offers studio-quality sound, yet is rugged enough towithstand 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 canceling, 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 unwanted background noise. It discriminates against distant sound sources such as monitor speakers or instruments. An announcer can sit in the standswith the audience, with the P.A. loudspeakers playing loudly, and not experience feedback.

The CM-310A and CM-310ASW offer a choice of FLAT or RISING frequency response. The FLAT position sounds warm and smooth, while the RISING position sounds clear and crisp. The FLAT position has slightly more gain beforefeedback than the RISING position. Announcers may prefer the RISING position for its extra intelligibility.A DIP switch inside the mic handle sets the frequency response.

The mic’s outstanding performance is complemented 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 carrying pouch, the ASA-2 mic stand adapter, and the WS4 windscreen for outdoor use.

Features:

• 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.

Specifications:

• Transducer type: Electret condenser.
• Frequency response (typical): 80 Hz to 15,000 Hz.
• Polar pattern: Cardioid.
• 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 pin1 of output connector.
• Polarity: Positive pressure on the diaphragm produces a positive voltage on pin 2 with respect topin 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).
• Included accessories: Carrying pouch, ASA-2 microphone 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.

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