MX391
Surface Mount
Microphones
Shure Microflex
MX391 Series microphones
®
are small, surface-mounted electret condenser
microphones designed for mounting on confer-
ence tables, stage floors, and lecterns. Their
high sensitivity and wide frequency range make
them especially suitable for picking up speech
and vocals in sound reinforcement and recording
applications.
Features
• Flat frequency response across the vocal range
for uncolored sound
• Interchangeable cartridges that provide a
choice of polar pattern for each application
• Sleek, low-profile design for unobtrusive
appearance
• RF filtering
Model Variations
Microflex MX391 microphones are available in
black or white.
The polar pattern of the included cartridge is indi-
cated by a model number suffix:
/C Cardioid
/S Supercardioid
/O Omnidirectional
2
Interchangeable Cartridges
Microflex microphones
use interchangeable car-
tridges that allow you to
choose the polar pattern
for different installations.
R183 Omnidirectional
R184 Supercardioid
R185 Cardioid
Microphone Placement
For best low-frequency response and rejection
of background noise, place the microphone on
a large, flat surface, such as a floor, table, or
lectern.
To reduce reverberance, avoid reflective surfaces
above or to the side of the microphone, such as
beveled sides of pulpits or overhanging shelves.
Permanent Installation
1. Remove grille.
2. Place housing in position and mark location of
screw holes and bottom cable exit hole.
3. Drill starter hole for each screw and a 1/2 in.
bottom exit hole for the mic cable.
4. Insert 4-pin mini-connector and cable through
cable hole.
5. Replace grille with screw. Do not overtighten.
Do not attempt to detach the cable from the mi-
crophone, as damage may result.
PREAMP
Preamp Gain
If necessary, the preamplifier gain can be reduced
by 12 dB. Contact an authorized Shure service
center for information.
RFI Filtering
Important: Microphones must be used with the
RK100PK preamp to optimize RF immunity.