Crown PZM-11 User Manual

Specifications

Type: 

 Pressure Zone Microphone.

Element:  

Electret condenser.

Frequency response (typical): 

 80 Hz to 20,000 Hz.

See Fig. 1.

Polar pattern:

  Hemispherical.

Impedance:

  225 ohms, balanced. Recommended

minimum load impedance 1000 ohms.

Open circuit sensitivity:

  5 mV/Pa* (–46 dBV/Pa).

Power sensitivity: 

 –45.5 dBm/Pa*, EIA rating

–139 dBm.

Equivalent noise level (self-noise): 

 26 dB SPL

typical (0 dB = .0002 dyne/cm

2

), A-weighted.

S/N Ratio:

  68 dB at 94 dB SPL.

Maximum SPL:

  120 dB SPL produces 3% THD.

Output connector: 

 Three screw terminals.

1 = ground, 2 = audio (hot), 3 = audio (return).

Polarity:  

Positive pressure on the diaphragm

produces a positive voltage on screw terminal 2
with respect to screw terminal 3

.

Operating voltage:  

Standard phantom power, 12 to

48 volts DC on screw terminals 2 and 3 with
respect to screw terminal 1.

Current drain:  

400 microamperes.

Materials:  

Steel plate and high-impact plastic

capsule holder.

Finish:

  Off-white.

Net weight: 

 2.5 oz. (71 g).

Dimensions:

  See Fig.2.

Optional accessories: 

  Crown PH-1A phantom

power supply (1 channel, battery or AC adapter
powered), Crown PH-4B phantom power supply
(4 channels, AC powered).

PRESSURE ZONE
MICROPHONE

®

Fig. 1

Fig. 2

T

he Crown PZM

®

-11 is a Pressure Zone

Microphone

®

 designed for security, sur-

veillance, and conference-room applica-

tions. It can be mounted in the ceiling or wall
in a standard electrical outlet box. Providing
excellent intelligibility, the PZM-11 is designed
to look like something other than a micro-
phone so as not to draw attention.

Like other Pressure Zone Microphones, the
PZM-11 utilizes the Pressure Recording Pro-
cess

™  

in which a miniature condenser

microphone capsule is mounted very close to
a sound-reflecting 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 com-
bines in-phase with sound reflected off the
boundary. The benefits are a wide, smooth
frequency response free of phase interference,
excellent clarity and “reach,” and consistent
pickup anywhere around the microphone.

In the PZM-11, 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. Powering is via 12 to 48 volts
phantom power.

Installation

1. Please refer to Fig. 3 and locate all the parts
shown.

2. Run a 2-conductor shielded microphone
cable to the ceiling or wall hole where you
intend to install the microphone. Install a
standard electrical outlet box in the hole.

3. Run the mic cable through the hole in the
electrical box and through the hole in the
chassis.

4. Service the end of the mic cable.

5. Attach the leads to the screw terminals.
Connect the cable shield to 1, light-colored
lead to 2, and darker lead to 3.

6. Place the chassis over the two long screws.
Using the nuts provided, secure the chassis to
the faceplate.

7. Using the two screws provided, secure the
faceplate to the electrical box.

*1 pascal = 10 dynes/cm

2

 = 10 microbars = 94 dB SPL.

–20

–25

–30

–35

20

100

1K

+15

+10

+5

dB 0

–5

–10

–15

10K

Frequency Response

Frequency in Hz

PZM-11

®