Crown Audio CM-312AE specifications Specifications, How to adjust for best fit

POLAR

PATTERN

CM-312AE

The Crown® CM-312AE is a rugged, lightweight headworn microphone designed for aerobics, live entertainment, and sports broadcasting. It is

intended for wireless-mic applications that require a light, inconspicuous mic.

The CM-312AE has no connector; you solder on a connector that mates with a wireless transmitter of your choice. Technical Bulletin #3 (included) shows the correct wiring for various transmitters.

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

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

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 the user’s face.

How to adjust for best fit

For best results, the CM-312AE MUST be custom fit- ted to one wearer’s head. This simple procedure takes only a few minutes. Please refer to Fig. 3 and locate the parts described.

1.If the microphone is for yourself, we suggest that you use a mirror to double check the fit as you make adjustments.

2.Loosen (just a little) the thumbscrew located on the outside of the foam block, part way back on the boom. This allows the boom to slide in and out, and to rotate left and right.

3.Now adjust the headband to fit your head. Put the foam block wire behind your ear.

Start bending the headband wire from the boom side, moving around to the other ear. The back of the headband should fit firmly against the back of the neck. If you can slide a finger between the headband and the back of your neck, then the headband is not fitted correctly. For users with smaller or petite heads, you may have to re-bend the earpiece around the ear, and cut off extra headband material.

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.

HYPERCARDIOID HEADWORN CONDENSER MICROPHONE

Specifications

Transducer type: Electret condenser.

Frequency response (typical): 50 Hz to 17,000 Hz (see Fig. 1).

Polar pattern: Hypercardioid (see Fig. 2).

Impedance: 6 kilohms unbalanced.

Recommended load impedance: 10 kilohms.

Open-circuit sensitivity, typical, close-talking:

2.9 mV/Pa* (–51 dB re 1V/Pa*).

Power sensitivity, typical, close-talking:

–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: 3–9V DC from the transmitter’s battery.

Polarity: Positive pressure on diaphragm produces posi- tive voltage on white lead with respect to shield.

Current drain: 0.27 mA nominal.

Battery life: Approximately equal to transmitter battery life.

Operating temperature range: –18° to +57° C, or 0° to +135° F.

Off-attenuation: 70 dB @ 1kHz.

Output connectors: Supply your own to match your transmitter.

Cable: 45-inches long (1.14-m), 2-conductor shielded unbalanced cable, unterminated. In-line with this cable is a small circuit module that equalizes the microphone signal. White lead is audio, red lead is DC bias, and shield is ground.

Materials: High-impact plastic and PVC mic housing, brass boom, steel wire headband.

Finish: Satin black.

Net weight: 1.5 oz (43 g).

Dimensions: Headband 5.5 in. (13.97 cm) diameter, adjustable. Boom approximately 5.75 in. (14.61 cm). See Fig. 6.

Included accessories: Microphone carrying case, WS-7 foam pop filter and clothing clip for aerobics.

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

Fig. 1

Frequency Response

+15
+10	0°, 1.375 in.
+5
dB 0
-5
-10
-15	0°, 2 ft.
-20
-25	120°, 2 ft.
-30
-35
20	100	1K	10K	20K

Frequency in Hz

Fig. 2

Polar Response

	330°	0°		30°
		FRONT
300°		-0		60°
		-5
		-10
		-15
		-20
270°				90°
240°				120°
				1000 Hz
				300 Hz
				6000 Hz
		REAR
	210°	180°		150°
Fig. 3	Parts
EARPIECE
HEADBAND
WIRE
FOAM BLOCK
WIRE
			BOOM	MIC

FOAM BLOCK

THUMBSCREW

DETAIL

TO MOVE MIC

UP OR DOWN

TO MOVE MIC

IN OR OUT

TO MOVE MIC

LEFT OR RIGHT