Crown Audio CM-311A Architects’ and Engineers’ Specifications, Microphone Warranty, Service

Fig. 4

Fig. 5

Note: For users with petite heads, extra headband material may have to be cut off to get the headband to fit properly.

4.Next, adjust the foam pad snug against your head or neck. To do this, bend the wire that goes into the foam block. CAUTION! Do not bend the boom itself

— just the foam-block wire. A snug fit of the foam pad prevents boom bounce when you move around.

5.Be sure that the thumbscrew is still loosened a little. Move the boom in or out, and left or right, to center the mic directly in front of your lips. The foam pop filter should press firmly against the lips. This is necessary because the mic cancels sounds that are not close to it. Also, it keeps the boom from bouncing. Tighten the thumbscrew and you’re done.

Once you’ve adjusted the headset, it should remain in that position -- no further adjustments are needed. You can still swing the mic up or down, away from your lips, if you don’t want to be heard on the P.A.

—or use the mic on/off switch programmed for “press off” operation.

After several hours of use, the foam pop filter can be- come clogged with moisture, giving a muffled sound. Periodically wash it in mild detergent and water. The foam pop filter is held in place by a removable ring.

Additional WS-6 pop filters can be ordered from Crown’s Parts Department.

How to insert a battery in the CM-311A belt pack

1.Access the battery by sliding open the battery cover.

2.Insert a fresh 9V alkaline battery (Mallory Duracell MN1604 or equivalent) into the battery tray. The bat- tery cover shows the correct polarity.

3.Replace the battery cover. To prolong battery life, turn off the battery switch when not in use.

If you’re using phantom power, and the battery switch is on, the battery will take over automatically if phan- tom power fails.

After 85 hours of use, or if the sound is distorted, it’s time to replace the battery.

How to program the mic on/off switch

The mic on/off switch can be programmed to work in three ways:

*Push-on/push-off.

*Momentary on.

*Momentary off (as supplied).

To change the switch operation, open the belt-pack case by removing the three screws. Set the switch as shown below:

The LED lights when the mic is on.

How to connect the CM-311AE to a wireless trans- mitter

1.Solder on a connector that mates with your trans- mitter. Technical Bulletin #3 (included) shows the correct wiring for various transmitters. A wireless transmitter must have separate leads for ground, audio and bias (3-9 volts).

2.Plug in the cable. Adjust the trim pot on the trans- mitter input to prevent distortion.

Note: Crown has certain models available for wireless transmitters from Shure, AKG, Audio-Technica and Telex. Contact Technical Support for more information at 800-342-6939.

Architects’ and Engineers’ Specifications

The microphone shall be the Crown Model CM-311A or CM-311AE or equivalent. The microphone shall be a head-worn, noise-cancelling, cardioid type of elec- tret-condenser design. The microphone shall exhibit excellent off-axis response and gain-before-feedback. The microphone shall have an adjustable headband, adjustable boom with locking thumbscrew, and foam pop filter.

Model CM-311A shall include a battery belt pack. Model CM-311AE shall be the head-worn micro-

CM-311A CM-311AE

phone alone. In the CM-311A, a 42-inch, permanently attached, two-conductor shielded cable shall con- nect the microphone to the belt pack. The belt pack shall include a 3-pin pro audio (XLR type) connector. In the CM-311AE, a 42-inch, permanently attached, two-conductor shielded cable can be connected to a transmitter.

Model CM-311A shall be powered by a 9V battery in the belt pack, or by 18 to 48V phantom power. The belt pack shall have a battery on/off switch, a pro- grammable mic on/off switch, and a “Mic On” LED. Model CM-311AE shall be powered by 3–9V DC from a transmitter.

Nominal open-circuit sensitivity shall be 4 or 1.25 mV/Pa. Maximum SPL shall be 148 dB SPL for 3% THD. Equivalent noise shall be 27 dBA nominal. Frequency response shall be 50 Hz to 17,000 Hz with a uniform off-axis response, over 20 dB down at the rear null. The Crown models CM-311A and CM-311AE are specified.

Microphone Warranty

Crown professional microphones are guaranteed against malfunction for a period of three years from date of original purchase. See enclosed warranty sheet for additional information.

Service

If the microphone does not function properly, check that it is aimed correctly and is connected as described in this datasheet. If the microphone is defective, return it in the original packaging to: Crown

Factory Service, 1718 West Mishawaka Road, Elkhart, IN 46517-9439.

A Service Return Authorization (SRA) is required for product being sent to the factory for service. An SRA can be completed on line at www.crownaudio. com/support/factserv.htm. For further assistance or technical support call 800-342-6939.

Crown International, Inc. 1718 W. Mishawaka Rd. Elkhart, IN 46517-9439 TEL: 574-294-8000 FAX: 574-294-8FAX www.crownaudio.com

© 2008 Crown Audio®, Inc. Specifications subject to change without prior notice. Latest information avalable at www.crownaudio.com. Crown, Crown Audio and Differoid are registered trademarks of Crown International.

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