Boundary Layer Microphones
Outdoor intercoms
Toll booths
Surveillance and security
Home automation
• Hemispherical polar pattern, excellent indelibility
• Weather-resistant model for outdoor use
• Line-level output connects directly to video recorders
• Inconspicuous, Mounts a standard wall plate
• Screw terminals for easy installation
The PZM®-11LLWR is a weather resistant Pressure Zone Microphone® with a balanced, line-level output.
A plastic membrane inside the microphone protects the mic capsule from water damage. The mic mounts in a standard electrical outlet box.
Applications include fast-food restaurants, outdoor intercoms, toll booths, bridges, theme park security, home automation, and so on.
The microphone can be plugged directly into a VCR line input — no costly mic preamp is needed. Output (via screw terminals) can be balanced or
unbalanced. Powering is by 12-24 V AC or DC.
In the PZM®-11LLWR, frequencies below the voice range are rolled off to reduce traffic rumble. The high-frequency response is boosted to help
articulation. Because of its tailored response and PZM® construction, the PZM®-11LLWR will pick up conversations or other desired sounds with
extra clarity.
The unit is “weather resistant”, which means:
• The microphone will work during and after rainfall.
• The mic’s frequency response will change temporarily if the membrane gets wet, but will return to normal when dry.
• If water freezes on the membrane, the mic’s frequency response will change, but will return to normal when the ice melts and the membrane dries.
Boundary Layer Microphones
1. Please locate all the parts shown. The electrical outlet box and cables are not included.
2. Run a 2-conductor shielded cable to the surface where you intend to install the
microphone. Install a standard electrical outlet box there (2-inch minimum depth).
3. The PZM® -11LLWR can be powered by 12-24 V AC or DC. From your power source, run
a twisted pair power cable to the mic location. Run the power cable through the hole in the
electrical box. Service the end of the power cable.
4. Run the mic cable through the hole in the electrical box. Service the end of the mic cable.
5. Connect the mic cable’s audio hot lead to the terminal labelled AUDIO +. Connect the audio
cold lead to the terminal labeled AUDIO –. Connect the cable shield to the terminal labelled
GROUND. If you plan to use an RCA or phone connector: Solder the cable shield to the long
lug, and solder the AUDIO + lead to the tip or pin. Do not connect the AUDIO – lead because
this may reduce the output level in an unbalanced configuration.
6. Attach the power leads to the screw terminals marked “~”. You can use 12-24 V AC or DC.
Polarity does not matter in either case.
7. Using the two shorter screws provided, attach the mic to the electrical box. Then use the
other two screws to secure the louvered wall plate to the microphone. Do not remove or
damage the plastic membrane.
8. If the mic cable is run in metal conduit, ground loops can occur that can cause hum. If hum
is present after installation, return the unit to Crown’s service dept. for ground-lift modification.
Architects’ and Engineers’ Specifications
The microphone shall be the Crown model PZM® -11LLWR or equivalent.
It shall be a Pressure Zone Microphone, mountable in a wall or ceiling, and designed not to look
like a microphone. It shall have a line-level output (1.4 V/Pa unloaded) and be powered by 1224V AC or DC, or phantom power.
The frequency response shall be from 80 Hz to 10,000 Hz with a low-frequency roll-off to reduce
rumble and high-frequency boost for articulation.
The audio connector and power connector shall be screw terminals. Output shall be balanced,
low impedance.
The electret condenser transducer shall have a hemispherical polar pattern when the microphone
is mounted in a wall or ceiling.
The PZM® -11LLWR microphone is specified.
Polar pattern:
Frequency response:
Equivalent noise level:
Maximum SPL:
Net weight:
80 to 10,000 Hz
75 ohms
26 dB-A
100 dB
Silver, may be painted any color.
71 g (2.5 oz)
Item number:
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