Crown Audio MB-4 specifications Features, Specifications, How to Paint the Microphone

POLAR

PATTERN

MB-4

he Crown® MB-4 is a miniature boundary Tmicrophone for multi-miking applications

such as teleconferencing, distance learning, boardrooms, courtrooms, and TV or theatrical applications. Double-sided sticky tape is pro- vided for attaching the unit under shelves, on walls, etc.

Thanks to its supercardioid pickup pattern, the MB-4 greatly reduces ambient noise and pickup of room reverberation. The result is a clearer sound.

MINI-BOUNDARY™

MICROPHONE

Features		• Half-supercardioid polar pattern reduces
•	Ideal for teleconferencing, distance	feedback, room acoustics and background
	learning, boardrooms and courtrooms	noise
•	Has a 15-foot attached cable leading to an	• Clear, natural sound
	XLR-type output connector with built-in
	mic electronics	• Small and inconspicuous

The MB-4 has a 15-foot attached cable leading to an XLR-type output connector with built-in mic electronics. It is powered by 12-48V phan- tom power, and is low-impedance balanced.

Features

• Tiny, inconspicuous.

• Can be used without putting holes in the

table.

• Clean, clear, natural sound.

• Low-Z balanced output prevents hum and

high-frequency loss.

• Removable grille assembly can be painted.

Specifications

Type: Phase Coherent Cardioid.

Element: Electret condenser.

Frequency response (typical): 50 Hz to 15,000 Hz at 30 degrees incidence to surface (see Fig. 1).

Polar pattern: Half-supercardioid (supercardioid in the hemisphere above the primary boundary). See Figs. 2 and 3.

Impedance: 150 ohms, balanced (recommended load impedance 1000 ohms or greater).

Open-circuit sensitivity (typical): 22 mV/Pa* (–33

dB re 1 volt/Pa).

Fig. 1

Frequency Response

+15
+10
+5		0°
dB 0
–5
–10		130°
–15
–20
–25
–30
–35	100	1K	10K
20

How to Paint the Microphone

1.Using a small screwdriver, pry open one side of the grille, then the other side (Fig. 5).

2.Remove foam liner.

3.Wearing a dust mask, spray-paint the grille assembly. Be sure grille holes are not clogged.

4.Allow paint to completely dry.

5.Make sure the LED is properly aligned.

6.Carefully place the grille assembly over the LED, and snap in place.

Installation

1.Typical placement for each mic is at arm’s

length from the user. Install one microphone in front of each person, or one between every two people.

If the microphone will be used on a lectern, install it on an open surface. Do not install it in a cavity or recessed area as the frequency response and polar pattern will be degraded.

2.Orient the mic so the word “Crown” is read- able by the user (right-side-up).

3.Plug a mic cable with a female XLR-type con- nector into the power module. Connect the other end of the cable to a phantom power supply. Or if your mixer has phantom power, connect the mic cable directly to a mic input and turn on phantom power.

.

Power sensitivity: –30.5 dB re 1 mW/Pa.* EIA rating –125 dBm.

Equivalent noise level (self-noise): 22 dB SPL typical (0 dB=0.0002 dyne/cm2), A-weighted.

S/N ratio: 72 dB at 94 dB SPL.

Maximum SPL: 120 dB SPL at 3% THD.

Polarity: Positive (inward) pressure on the diaphragm produces positive voltage on pin 2 with respect to pin 3.

Operating voltage: Phantom power, 12-48 volts DC on pins 2 and 3 with respect to pin 1 of output connector.

Current drain: 4 mA nominal. .

Connector: 3-pin pro audio, XLR-type.

Cable: Permanently attached, black, 15-foot (4.572- m), 2-conductor shielded cable from mic to power module or interface. No other cable supplied. Use two-conductor shielded mic cable from power module to mixer.

Materials: High-impact molded plastic and steel mesh mic grille, steel power module.

Finish: Satin black.

Operating temperature range: –10° to +50° C, or

+14° to +122° F.

Net weight: Microphone: 0.7 ounces (19.8 grams). Power module: 2.8 ounces (78.6 grams).

Dimensions: See Fig. 4.

Included accessories: Double-sided tape for fastening under shelves, etc., for theatrical applications.

Optional accessories: PH-1A phantom power supply (1 channel, battery or DC-adapter powered).

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

Frequency in Hz

Fig. 2

Vertical-Plane Polar Response

60°		90°	120°
			1 kHz
			200 Hz
			5 kHz
30°			150°
FRONT			REAR
0°	–5	–10 –15 –20	180°
+5 –0

Fig. 3

Horizontal-Plane Polar Response

330°	0°	30°
	FRONT
	–0
300°	–5	60°
	–10
	–15
	–20
270°		90°
240°		120°
		1 kHz
		200 Hz
	REAR	5 kHz
210°	180°	150°