PRESSURE ZONE
MICROPHONE®
®
PZM-11
T
he Crown PZM®-11 is a Pressure Zone
Microphone® designed for security, surveillance, and conference-room applications. 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 microphone so as not to draw attention.
Like other Pressure Zone Microphones, the
PZM-11 utilizes the Pressure Recording Process™ 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 combines 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.
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/cm2), 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).
*1 pascal = 10 dynes/cm2 = 10 microbars = 94 dB SPL.
Fig. 1
Frequency Response
+15
+10
+5
dB 0
–5
–10
–15
–20
–25
–30
–35
20
100
1K
Frequency in Hz
Fig. 2
10K
®
PZM-11
Fig. 3
MIC
CABLE
ELECTRICAL
BOX
NUTS
CHASSIS
LONG
SCREWS
FACEPLATE
SCREW
7. Using the two screws provided, secure the
faceplate to the electrical box.
8. If you plan to use a cable connector, solder
the other end of the mic cable to a 3-pin professional audio connector (XLR-type). Solder
the cable shield to pin 1, light-colored lead to
pin 2, and darker lead to pin 3.
9. If you plan to use a cable connector, connect the 3-pin pro audio connector to the input
of a phantom power supply. Crown makes a
PH-4B phantom power supply (4 channels,
AC-powered) and PH-1A phantom power supply (1 channel, battery or AC-adapter powered).
10. Connect the output of the phantom supply to your equipment mic input. Or, if your
mic input has phantom power built in, simply
connect the mic cable to the mic input.
11. If the mic cable is run in metal conduit,
ground loops might occur that can cause
hum. If hum is present after installation, remove the ground-lift jumper (labeled GND
LIFT) on the printed-circuit board.
Architects’ and Engineers’ Specifications
The microphone shall be the Crown Model
PZM-11 or equivalent. The microphone shall
be a Pressure Zone Microphone, electretcondenser type, with built-in electronics interface. The microphone capsule holder shall
be mounted on a standard switch plate. The
microphone shall be powered from 12-48V
phantom power. The output shall be low impedance balanced. Frequency response shall
be from 80 Hz to 20,000 Hz. Low frequencies
below the voice range shall be rolled off.
Open-circuit sensitivity shall be 5 mV/Pa
(–46 dB re 1V/Pa). Maximum SPL capability
shall be 120 dB SPL at 3% THD. Equivalent
noise shall be 26 dBA typical (0 dB = .0002
dyne/cm2). The Crown model PZM-11 microphone is specified.
Service
If the unit fails to work, first replace or repair the
mic cables and check the power supply. Recheck your connections to the microphone
screw terminals. If service is required, return the
microphone and the electronic interface in the
original packaging to Crown Service Department, Plant 2 SW, 1718 West Mishawaka
Road, Elkhart, IN 46517. For further assistance
or technical support call 800-342-6939.
Warranty
Crown professional microphones are guaranteed unconditionally against malfunction
from any cause for a period of three years
from date of original purchase. See enclosed
warranty sheet for additional information.
Crown International, Inc.
P. O. Box 1000
Elkhart, IN 46515-1000
TEL: 219-294-8000
FAX: 219-294-8FAX
PZM-11 Schematic
©2000 Crown International, Inc.
Specifications subject to change without prior notice.
Crown® is a registered trademark of Crown International, Inc. PZM® and Pressure Zone Microphone® are
registered trademarks of Crown International, Inc.
Pressure Recording Process™ is a trademark of E.M.
Long Associates.
02/00
127006-2