Features | |
• Ideal for security, surveillance and conferrence rooms | • Low-impedance screw-terminal output |
| • Inconspicuous |
• Clear, articulate sound | • PZM-11 is mic level; PZM-11LL is line level |
T
he Crown® PZM®-11 or PZM-11LL is aPressure Zone Microphone® designed for
conference-room, security and surveillance
applications. Each can be mounted in the ceiling or
wall in a standard electrical outlet box. Providing
excellent intelligibility, the PZM-11 and
PZM-11LL are designed to look like a light switch
so as not to draw attention.
The
PZM-11 has a mic-level output and is poweredby 12-48V phantom power.
The
PZM-11LL has a line-level output and can bepowered by 24V AC, 12-24V DC, or 12-48V phantom
power. Since the PZM-11LL has a high output,
it can be plugged directly into a VCR line input—no
costly mic preamp is needed.
To phantom power the PZM-11LL, a modifi cation
will have to be made to the electronics module (see
Installation Step 3 for details).
Like other Pressure Zone Microphones, the
PZM-11and PZM-11LL utilize the Pressure Recording
Process™ in which a miniature condenser
microphone capsule is mounted very close to a
sound-refl ecting plate or boundary. The capsule
is mounted in the “Pressure Zone” just above the
boundary, a region where sound coming directly
from the sound source combines in-phase with
sound refl ected off the boundary. The benefi ts are
a wide, smooth frequency response free of phase
interference, excellent clarity and “reach,” and consistent
pickup anywhere around the microphone.
In the PZM-11and PZM-11LL, low frequencies
below the voice range are rolled off to reduce
pickup of air-conditioning rumble. The high-frequency
response is boosted slightly to aid clarity
and articulation.
The microphone connector is a row of screw terminals
for easy installation. The output is balanced,
low impedance, which allows long cable runs
without hum pickup or high-frequency loss.
Specifi cations
Type:
Pressure Zone Microphone.Element:
Electret condenser.Frequency response (typical):
80 Hz to 20,000 Hz.See Fig. 1.
Polar pattern:
Hemispherical.Impedance:
PZM-11: 225 ohms, balanced.
PZM-11LL: 75 ohms, balanced.
Recommended minimum load impedance 1000
ohms.
Open circuit sensitivity:
PZM-11: 5 mV/Pa* (–46 dBV/Pa).
PZM-11LL: 1.4V/Pa* (+3 dB re 1V/Pa).
Power sensitivity:
PZM-11: –45.5 dBm/Pa*
PZM-11LL: +8 dBm/Pa*.
Equivalent noise level (self-noise):
26 dB SPL typical(0 dB = .0002 dyne/cm2), A-weighted.
S/N Ratio:
68 dB at 94 dB SPL.Maximum SPL:
PZM-11: 120 dB SPL produces 3% THD.
PZM-11LL: 100 dB SPL produces 3% THD.
Output connector:
Three screw terminals.1 = ground, 2 = audio hot (in polarity),
3 = audio cold (opposite polarity).
Polarity:
Positive pressure on the diaphragm producesa positive voltage on screw terminal 2 with
respect to screw terminal 3
.Operating voltage:
PZM-11: Standard phantom power, 12 to 48V DC
on screw terminals 2 and 3 with respect to screw
terminal 1.
PZM-11LL: 24V AC, 12-24V DC, or phantom
power as the PZM-11LLS2.
Current drain:
PZM-11: 400 microamperes.
PZM-11LL: 4 milliamperes.
Materials:
Steel plate and high-impact plasticcapsule holder.
Finish:
Off-white. May be painted any color; takecare to fi rst seal the opening between the mic
capsule and boundary plate.
Operating Temperature Range:
–10° to +60° C(+14° to +140° F).
Net weight:
2.5 oz. (71 g).Dimensions:
See Fig. 2.Optional accessories:
Crown PH-1A phantom powersupply (1 channel, AC-adapter powered).
*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.
