Crown CM-311A
Differoid® Head-Worn
Condenser Microphone


By Mark Farmer
If there was ever one thing Garth Brooks was noted for was his headset microphone coming out from the brim of his cowboy hat. Garth is one of the fore fathers to bring country into the 90’s. He took all the elements of what makes country great, took it one step further by turning it into a stadium size event and began wearing a headset microphone. This used in conjunction with a wireless unit, takes Garth and the likes of Janet Jackson everywhere they want to go during their concerts.
FEATURES
One of the benefits of this headset design is it allows the performer to be seen not standing behind a microphone stand. Performers who stand behind a mic are typically only seen from the nose up. The Crown CM-311A is a cardioid pattern which uses Crown’s Differoid® technology to reject sounds from the rear of the microphone. This innovation allows high volume levels in on-stage monitor mixes or crowd noise to be rejected for a high gain before feedback. singing drummer’s, sports announcers, juggler’s, musicians and other various entertainers would all benefit from purchasing this mic. With a headset weight of only 2.1 oz, one can barley notice it is being worn. The headset is hard wired into a belt pack to prevent a mic jack from popping loose or connection related problems The belt pack with battery installed has a insignificant weight of only 6.1 oz. If interested in adding this same headset and element to your favorite wireless belt pack, Crown has the CM-311A/E available, which terminates to bare wire. The Crown CM-311 belt pack can be powered by a 9 volt battery or by phantom power. Accessible on the top of the belt pack is a programmable mic on/off switch. This switch can be set up to work in three different ways, push on or push off, momentary on, or as it is supplied from Crown, momentary off. Removing three screws to the belt pack case allows access to a miniature switch to change the switch settings. The flexibility of these switches would allow a performer or announcer to turn the mic off completely or just press and hold the button in the instance of coughing or clearing ones throat. Next to the switch is a small red LED, which lights after the unit power switch has been turned on. A large metal belt-clip is permanently attached to the belt pack for hands free use. For ease of hook up, a male XLR connector is recessed within the bottom of the high-impact plastic belt pack.
The headset headband is made of bendable steel wire. The mic boom is constructed from durable non-flexible brass tubing. The 2-conductor shielded cable is 42 inches in length from headset to belt pack. A small clip is fastened to the cable for attaching to one’s clothing. The microphone element is housed within a small rounded silver grill, which is attached to the fully adjustable brass mic boom. A large user friendly knob or thumbscrew allows for complete adjustment of the boom, in or out and down or up. Attached to the underside of this knob is a large padded foam block. This block sits just below the right ear and becomes the stabilizer for the mic boom and element. To prevent the mic boom from bouncing, Crown suggests bending the headband wire, both side ear pieces and the wire assembly which holds the padded block for the best fit possible. Included with the mic is a foam pop filter which snaps down over the metal windscreen. The transducer on the head set is called an electret condenser.The element reproduces frequencies from 50 Hz to 17 kHz and has a cardioid pattern. This element can take up to a maximum SPL of 148 dB with only 3% THD according to Crown’s manual. The manual also states, up to 110 hours of battery usage can be achieved.
IN USE
The summer, for many mid-western sound companies, is fair and festival season. That was the case, as I had of the Ohio State Fair with seventeen days of various acts to try out the microphone for me. With a separate monitor system and a front of house board we were able to test out the mic in the monitors as well as the house system. Knowing my own voice, I choose to listen to the head set through the house system first, after plugging in directly into the FOH console. My headphones, Sony MDR-V600, also became a source to listen to the CM-311A from. I was impressed from the beginning with the Crown’s ability to reproduce my voice with such accuracy. I managed to get a drummer from one band and a lead singer from another to wear and try out the head set for me.

Mark Farmer is a sound engineer with Live Technologies in Columbus, Ohio He is a regular contributer to PAR, and can be reached on the internet via: mixthat@columbus.rr.com

Product Points

Crown CM-311A Head Mic

PLUS
+High gain before feedback
+Natural vocal reproduction
+Lightweight

MINUS
-None

THE SCORE
Splendid