The PZM-11LL is the same as the PZM-11, but has a
line-level output. This lets you record directly into a
VCR without a mic preamp. The PZM-11LL can be
powered in two ways: 24V AC or 12-24V DC. In
video security systems, 24V AC is usually available,
and this can be used to power the mic. The output
connector is screw terminals.
The PZM-11LLWR is the same as the PZM-11LL,
but is weather resistant.
MB-3
This is a miniature supercardioid mic with attached
electronics that mounts in a ceiling panel, wall or
table. The mic comes with an XLR-type connector
and requires 12-48V phantom power.
GLM-100
This mini omnidirectional mic is easy to install tem-
porarily. Just tape it to any convenient surface. The
mic has an XLR-type output and runs off phantom
power.
The GLM-100/E is the same, but can be connected
directly to a wireless transmitter. At the end of the
mic cable, you solder on a connector that mates with
your transmitter.
APPLICATIONS
Large rooms (warehouses, parking
garages, offices, etc.)
One way to cover a large room is with PZMs on the
ceiling (Fig. 1).
Figure 1
How far apart should the mics be to get uniform cov-
erage? Use the 2-to-1 rule. The spacing between
mics should be two times the distance from mouth to
ceiling. For example, if the ceiling is 5 feet above the
talkers’ mouths, the mics should be 10 feet apart.
Then the mics will pick up everyone about equally.
In general, use as few mics as possible that will do
the job.
If several mics are on at the same time, the recorded
sound might be reverberant or muddy. It helps to run
all the mics into a gated mixer (automatic mixer),
which turns on only one mic at a time – the one near-
est the person speaking. This keeps the sound clear.
If the ceiling is very high, mount the PZM-11 or
PZM-11LL on support posts and/or walls, about 10
feet off the floor (out of reach).
