Crown Audio MB-1AL specifications MB-1 Features, How to Paint the Microphone

POLAR

PATTERN

MINI-BOUNDARY™

MICROPHONE

MB-1

MB-1AL

he Crown® MB-1 is a miniature bound- Tary microphone for multi-miking applica-

tions such as teleconferencing, distance learning, boardrooms, and courtrooms.

Features
Perfect for multimiking applications in telecon-	Half-supercardioid polar pattern reduces
ferencing, distance learning, boardrooms and	ambient noise and room reverberation
courtrooms	Very small and inconspicuous
Phase Coherent Cardioid® design prevents	Mic plugs into an insert in the table
coloration from surface sound reflections

A low-profile circular microphone, the MB-1 has a bottom-mounted phone plug. Supplied with the mic is a table insert with a phone jack that accepts the mic. The insert flush-mounts in a hole drilled in the table. After meetings, the mic can be removed and the insert covered with the provided disk.

Thanks to its half-supercardioid pickup pattern, the MB-1 greatly reduces ambient noise and pickup of room reverberation. The result is a clearer sound.

The MB-1 must be used with an MB-100 in- terface (not included). The interface performs these functions:

Specifications

All specs apply to each output of the interface with a mic connected.

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).

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

Insert Finish: MB-1: black anodized, MB-1AL: alu-

minum.

Net weight: Microphone: 0.7 ounces (19.8 grams). Table insert: 3.9 ounces (109 grams).

Dimensions: See Figs. 4a and 4b.

Included accessories: Table insert with stereo phone jack. Disk to cover insert when mic is removed.

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

Fig. 1

Frequency Response

•	Powers and equalizes up to four mics
•	Provides programmable switching to turn
	the mic on or off if desired (switches not

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

–125 dBm.

Equivalent noise level (self-noise): 22 dB SPL typical

+15

+10

+5

dB 0

0˚

provided).

(0 dB=0.0002 dyne/cm2), A-weighted.

–5

• Pluggable microphone inputs

• Provides balanced outputs from the interface

MB-1 Features

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 interface output termi- nal 1 with respect to terminal 3, and on terminal 4

–10

–15

–20

–25

–30

–35

130˚

•Painted removable grille assembly

•Miniature mic plugs into jack in table insert

•Clean, clear, natural sound

•Low-Z balanced output prevents hum and high-frequency loss

•Defeatable LED

•Choice of insert finishes:

Black anodized (MB-1).

Paintable aluminum (MB-1AL)

How to Paint the Microphone

1.Using a small screwdriver, pry open one side of the base, 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.

with respect to terminal 6.

Operating voltage (interface): 18-48V phantom power.

Current drain: 5 mA nominal with LED on, 4 mA nomi- nal with LED off.

Operating temperature range: –10° to +50° C, or +14°

to +122° F.

Mic connector: Stereo phone plug. Mates with stereo phone jack in supplied insert.

Cable connectors (supplied with MB-100 interface):

•Two pluggable terminal blocks (PTBs) in line with the microphones. Each input connector handles up to two mics.

•Two PTBs for output connectors to your mixer. Each output connector feeds two mixer mic inputs.

•Two PTBs for remote switch sensing. Each PTB connects to two remote switch sensors.

Cable: None supplied. Use two-conductor shielded mic cable between phone jack and pluggable terminal block. Use two-conductor shielded mic cable be- tween interface output and mixer input. Use twisted- pair cable between each user switch and interface.

20 100 1K 10K

Frequency in Hz

Fig. 2

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˚