Crown Mini-Boundary MB-1 Datasheet

MB-1
MB-1AL
T he Crown ® MB-1 is a miniature bound-
ary microphone for multi-miking applica-
tions such as teleconferencing, distance
learning, boardrooms, and courtrooms.
A low-profi le 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 fl ush-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:
• Powers and equalizes up to four mics
• Provides programmable switching to turn
the mic on or off if desired (switches not
provided).
• Pluggable microphone inputs
• Provides balanced outputs from the interface
MB-1 Features
• 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 fi nishes:
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.
POLAR
PATTERN
MINI-BOUNDARY
MICROPHONE
Features
Perfect for multimiking applications in telecon-
ferencing, distance learning, boardrooms and
courtrooms
Phase Coherent Cardioid
coloration from surface sound refl ections
Specifi cations
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).
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/cm
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
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.
™
design prevents
®
*1 pascal = 10 dynes/cm
Fig. 1
dB 0
2 ), A-weighted.
Fig. 2
300˚
270˚
240˚
Half-supercardioid polar pattern reduces
ambient noise and room reverberation
Very small and inconspicuous
Mic plugs into an insert in the table
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.
2 = 10 microbars = 94 dB SPL.
Frequency Response
+15
+10
+5
0˚
–5
–10
130˚
–15
–20
–25
–30
–35
20 100 1K
Frequency in Hz
Horizontal-Plane Polar Response
330˚ 0˚
FRONT
–0
–5
–10
–15
–20
REAR
210˚ 180˚
10K
30˚
60˚
90˚
120˚
1 kHz
200 Hz
5 kHz
150˚