AKG MB4 User Manual

T

Fig. 1. Frequency Response

Fig. 2. Horizontal-Plane Polar Response

Fig. 3. Vertical-Plane Polar Response

MINI-BOUNDARY
MICROPHONE

™

MB4

he AKG/Crown® MB4 is a miniature
boundary microphone for multi-miking

applications such as teleconferencing,
distance learning, boardrooms,
courtrooms, and security applications.
Double-sided sticky tape is provided for
attaching the unit under shelves, on walls,
etc.
Thanks to its supercardioid pickup pattern,
the MB4 greatly reduces ambient noise
and pickup of room reverberation. The
result is a clearer sound.
The MB4 has a 15-foot attached cable
leading to an XLR-type output connector
with built-in mic electronics. It is powered
by 12-48V phantom power, and is low­impedance balanced.

Features

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the table.

•

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hum and high-frequency loss.

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How to Paint the Microphone

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

2. Remove the foam liner.

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

4. Allow to completely dry.

5. Make sure the LED is properly aligned.

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

Installation

1.

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

2.

the user (right-side-up).

3.

connector 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.

Tiny, inconspicuous.
Can be used without putting holes in

Clean, clear, natural sound.
Low-Z balanced mic-level output prevents

Removable grille assembly can be painted.

In a table, typical placement for each mic is

Orient the mic so the readable lable faces

Plug a mic cable with a female XLR-type

lectern,

Specifications

Type:

Phase Coherent Cardioid.

Element:
Frequency response (typical):

30 degrees incidence to surface (see Fig. 1).

Polar pattern:

the hemisphere above the primary boundary).
See Figs. 2 and 3.

Impedance:

load impedance 1000 ohms or greater).

Open-circuit sensitivity (typical):

(–33 dB re 1 volt/Pa).

Power sensitivity:

EIA rating

Equivalent noise level (self-noise):

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

S/N ratio:
Maximum SPL:
Polarity:

diaphragm produces positive voltage on pin 2
with respect to pin 3.

Operating voltage:

on pins 2 and 3 with respect to pin 1 of output
connector.

Current drain:
Connector:
Cable:

(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:

mesh mic grille, steel power module.

Finish:
Net weight:
Operating temperature range:

to +122°F.

Net weight:

Power module:

Dimensions:
Included accessories: Double-sided tape for

fastening under shelves, etc., for theatrical
applications.

Optional accessories:

supply (1 channel, battery or DC-adapter
powered). PH4A phantom power supply (4
channels, AC powered).

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

Electret condenser.

Half-supercardioid (supercardioid in

150 ohms, balanced (recommended

–30.5 dB re 1 mW/Pa*.

–125 dBm.

72 dB at 94 dB SPL.

Positive (inward) pressure on the

3-pin pro audio, XLR-M type.

Permanently attached, black, 15-foot

High-impact molded plastic and steel

Satin black.

2.7 ounces (78 grams).

Microphone: 0.7 ounces (19.8 grams)

120 dB SPL at 3% THD.

Phantom power, 12-48 volts DC

4 mA nominal.

2.8 ounces (78.6 grams)

See Fig. 4.

PH1A phantom power

50 Hz to 15,000 Hz at

22 mV/Pa*

22 dB SPL

-10° to +50°C, or +14°

MB4

Fig.4

Architects’ and Engineers’ Specifications

The microphone shall be the AKG/Crown
model MB4 or equivalent. The microphone
shall be a
condenser type. The microphone shall use

the principle of phase co
mounting a small-diameter element very near a
boundary. This eliminates comb filtering in the
audible spectrum.

The microphone will exhibit excellent off-axis
response and gain-before-feedback. The MB4
shall have a permanently attached 15-foot
(4.572 m) cable connected to an XLR-type con­nector with built-in mic electronics. Powering
shall be by 12-48V phantom power.

At the output connector, nominal sensitivity shall
be 22 mV/Pa. Maximum SPL shall be 120 dB
SPL for 3% THD. Equivalent noise shall be 22
dBA nominal. Frequency response shall be 50
Hz to 15 kHz with a uniform off-axis response,
about 20 dB down at the rear nulls.

The AKG/Crown model MB4 is specified.

© 2015 HARMAN International Industries, Incorporated. All rights reserved. AKG is a trademark of AKG Acoustics GmbH, registered in the United
States and/or other countries.
Features, specifications and appearance are subject to change without notice.

www.akg.com

half-supercardioid electret

herency achieved by

AKG ACOUSTICS GMBH LAXENBURGER STRASSE 254, 1230 VIENNA/AUSTRIA
AKG ACOUSTICS, U.S. SERVICE 24950 GROVE VIEW ROAD, MORENO VALLEY, CA 92551, U.S.A

Warranty

AKG/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 data
sheet. If there is hum or no signal, first
repair or replace the cable.

determine that the microphone
product is defective, return the
complete product in its original
packaging to one of the addresses
below . For further assistance or
technical support call the international
helpdesk at [phone].

If you