POLAR
PATTERN
™
MINI-BOUNDARY
MICROPHONE
MB-4
MB-4E
he Crown® MB-4 is a miniature boundary
microphone for multi-miking applications
such as teleconferencing, distance learning,
Features
• Half-supercardioid polar pattern reduces
feedback, room acoustics and background
noise
T
• Ideal for teleconferencing, distance
learning, boardrooms and courtrooms
• Has a 15-foot attached cable leading to an
XLR-type output connector with built-in
mic electronics
boardrooms, courtrooms, and TV or theatrical
applications. Double-sided sticky tape is pro-
vided for attaching the unit under shelves, on
walls, etc.
• Clear, natural sound
Thanks to its supercardioid pickup pattern, the
MB-4 greatly reduces ambient noise and pickup
of room reverberation. The result is a clearer
sound.
• 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.
Specifications
MB-4 specifications are at the mic cable connec-
tor. MB-4E specifications are at the interface output
terminals.
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 (MB-4 only): PH-1A phantom
power supply (1 channel, battery or DC-adapter
powered).
Required accessory (MB-4E only): Crown MB-100 or
MB-200 Interface.
The MB-4E is the same, but without the elec-
tronics/connector.
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).
Power sensitivity: –30.5 dB re 1 mW/Pa.* EIA rating
–125 dBm.
The MB-4E must be used with the Crown MB-
100 or MB-200 interface (not included). The
interface provides these functions:
• Powers and equalizes up to four mics.
• Provides programmable switching to turn
the mic on or off if desired (switches not
provided).
• The MB-200 interface also has remote
switch sensing via an optical coupler.
• Pluggable microphone inputs.
• Provides balanced outputs from the inter-
face.
*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.
Fig. 1
Frequency Response
Equivalent noise level (self-noise): 22 dB SPL typical
(0 dB=0.0002 dyne/cm2), A-weighted.
+15
+10
Features
S/N ratio: 72 dB at 94 dB SPL.
Maximum SPL: 120 dB SPL at 3% THD.
+5
• 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.
• LED indicates mic on (MB-4E only).
• LED in MB-4E is defeatable.
• Switches can be internally programmed
for touch-on/touch-off, momentary on, or
momentary off.
• Remote sensing of switch closure (in MB-
200 interface).
• Removable grille assembly can be painted.
0˚
dB 0
–5
Polarity (MB-4): Positive (inward) pressure on the
diaphragm produces positive voltage on pin 2 with
respect to pin 3.
Polarity (MB-4E): Positive (inward) pressure on
diaphragm produces positive voltage on interface
output terminal 1 with respect to terminal 3, and on
terminal 4 with respect to terminal 6.
Operating voltage (MB-4): Phantom power, 12-48
volts DC on pins 2 and 3 with respect to pin 1 of
output connector.
Operating voltage (MB-4E): 18-48V phantom power
at interface output.
Current drain (MB-4): 4 mA nominal.
Current drain (MB-4E): 4 mA nominal with LED off, 5
mA nominal with LED on.
Connector (MB-4): 3-pin pro audio, XLR-type.
–10
130˚
–15
–20
–25
–30
–35
10K
20
100
1K
Frequency in Hz
How to Paint the Microphone
1. Using a small screwdriver, pry open one side
of the grille, then the other side (Fig. 5).
Fig. 2
Vertical-Plane Polar Response
Connector (MB-4E): Pluggable terminal block (one
block per every two microphones).
60˚
90˚
120˚
2. Remove foam liner.
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, or from MB-100 Interface to
mixer.
Materials: High-impact molded plastic and steel mesh
mic grille, steel power module.
Finish: Satin black.
1 kHz
200 Hz
5 kHz
3. Wearing a dust mask, spray-paint the grille
assembly. Be sure grille holes are not clogged.
150˚
30˚
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.
FRONT
REAR
180˚
0˚
+
5
–0 –5 –10 –15 –20
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