Electro-Voice RE90B Specifications

Description
The Electro-Voice RE90B and RE90BW are
part of the Architectural Microphone Series.
The RE90B is a full-range condenser mi-
crophone designed to be used for surface
mounted applications such as distance learn-
ing centers, video conferencing systems,
teleconferencing systems, and sound rein-
forcements (see Figure 1). The polar pat-
tern of the RE90B is half-cardioid (half-
space cardioid) to promote good gain-be-
fore-feedback and suppress ambient noise
(see Figure 2).
All boundary type microphones operated on
a flat surface are subject to an increase in
sensitivity of the microphone with increas-
ing frequency; this is called the baffle ef-
fect. To counteract this effect, the RE90B
has been designed with internal equaliza-
tion to give the RE90B a flat sensitivity re-
sponse. The RE90B is designed to be pow-
ered by an external 9-52 V dc phantom
power supply (DIN 45 596).
The RE90B microphone is encased in a
heavy-duty zinc die cast body protected by
a strong, perforated steel screen. The body
of the microphone is designed to provide
two distinctive functions. First, the case is
electronically isolated from the surface that
it is placed on by virtue of the rubber friction
pad and the internal fiber washers when per-
manently mounted. Second, the microphone's
miniature cable can be routed directly from
the rear of the microphone, or the cable may
be directed from the bottom of the micro-
phone though the table top without exposing
the microphone cable. The microphone cable
is connected to the microphone by a pilfer-
resistant internal terminal block. For perma-
nent installation, a drilling template is pro-
vided.
The RE90B's body is designed as a low-pro-
file housing. Both microphones are shock
mounted through a combination of a heavy
diecast case, a rubber nonslip bottom pad, and
internal padding of the microphone and
printed circuit board. This combination of
isolation minimizes the mechanical coupling
of surface vibrations to the microphone.
For the RE90B, a 1.8-m (6 ft.) black minia-
ture shielded two-conductor cable is provided
with a male XLR-type connector. The
RE90BW is provided with a 1.8-m (6 ft.)
white miniature shielded two-conductor cable
with a male XLR-type connector.
Installation and Operation
The RE90B is a boundary style microphone;
therefore the symmetry and area of the mount-
RE90B and
RE90BW
Full-Range Condenser
Desk-Mount Microphone
• Nonreflecting black (RE90B) or
low-gloss white (RE90BW).
• Ultra-low profile
• Half-cardioid polar response promotes
excellent gain-before-feedback
• Full, non-slip shock pad electrically
and mechanically isolates case from
mounting surface
• lnternally equalized for natural
response on large surfaces
• Tamper-resistant terminal block
connections for fixed or temparary
applications
ing surface directly affect the sensitivity and
response of the microphones. To mount the
RE90B on a rectangular surface, the micro-
phone should be centered on the surface and
positioned with the front of the microphone
facing the sound source along the longer di-
mension of the mounting surface. Ideally,
the sources of sound should be situated be-
tween the mounting surface and 60 degrees
above the plane of the mounting surface (see
Figure 3).
The RE90B is supplied with a 1.8-m (6 ft.)
miniature shielded cable with a male XLR-
type connector. The RE90B is provided with
the miniature shielded cable connected to the
microphone for temporary installation. For
permanent installation, the cable can be
routed through the bottom of the micro-
phone. A drilling template is provided. The
cable is disconnected from the microphone
by first removing the cross-recessed screw
on the top of the microphone, removing the
protective grille screen and pop filter, then
loosening the three screws on the terminal
block. When reattaching the miniature cable,
the contacts' functions are printed on the
printed circuit board (see Figure 4).
The RE90B has a balanced low-impedance,
transformerless output. The balanced sig-
nal appears across Pins 2 and 3 while the