Crown Audio PZM-10LL Microphone User Manual


 
PRESSURE ZONE
MICROPHONES
T
he Crown
®
PZM
®
-10 and PZM-10LL,
part of the Pressure Zone Microphone
®
line, are designed for security, surveil-
lance, and conference-table use. Since they
do not look like microphones, they are incon-
spicuous. Each mic’s tubular housing mounts
in a 25/32-inch diameter hole in a ceiling
panel, wall or table.
The PZM-10 has a mic-level output and a
3-pin XLR-type connector for easy plug-in
installation. The mic requires 12 to 48V
phantom power.
The PZM-10LL has a line-level output from
its unterminated cable. It requires 12 to 24V
DC.
Like other Pressure Zone Microphones, the
PZM-10 and PZM-10LL use a miniature mic
capsule mounted very near a sound-refl ect-
ing plate or boundary, in the Pressure Zone.
In this zone, direct sound from the sound
source combines in phase at all frequencies
with refl ected sound off the boundary. The
benefi ts are many: 6 dB more sensitivity,
6 dB less noise, a wide smooth frequency
response free of phase interference, excellent
clarity and “reach,” and consistent pickup
anywhere around the mic.
Frequencies below the voice range are rolled
off to reduce pickup of air conditioning rum-
ble. The high-frequency response is boosted
slightly to help articulation. Because of their
tailored response and PZM construction, the
PZM-10 and PZM-10LL will pick up conver-
sations or other desired sounds with extra
clarity and defi nition.
The output is balanced, low impedance,
which allows long cable runs without hum
pickup or high-frequency loss.
The mic’s humbucking transformer and steel
case prevent hum pickup, even near fl uores-
cent lights.
Mic Placement
To pick up speech from a small conference
table (about 6 feet square), mount the PZM-
10 or PZM-10LL in the middle of the table.
For longer tables, use one PZM in the middle
of every 4 to 6 people. No person should be
more than 3 feet from the nearest micro-
phone.
(continued on back)
Specifi cations
Transducer type: Electret condenser.
Frequency response (typical):
PZM-10: 80 Hz to 20,000 Hz. See Fig. 1. PZM-
10LL: 100 Hz to 20,000 Hz. See Fig. 2.
Polar pattern: Hemispherical.
Impedance:
PZM-10: 240 ohms, balanced.
PZM-10LL: 75 ohms, balanced. Recommended
minimum load impedance 1000 ohms.
Open circuit sensitivity:
PZM-10: 2.5 mV/Pa* (–52 dBV/Pa).
PZM-10LL: 1.4V/Pa* (+3 dBV/Pa).
See Table 1.
Power sensitivity:
PZM-10: –52 dBm/Pa*.
PZM-10LL: +8 dBm/Pa*.
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.
Operating voltage:
PZM-10: 12 to 48V phantom power, positive
voltage on pins 2 and 3 with respect to pin 1.
PZM-10LL: 12 to 24V DC, positive voltage on
red lead with respect to shield.
Polarity:
PZM-10: Positive pressure on the diaphragm
produces a positive voltage on pin 2 with
respect to pin 3 of output connector.
PZM-10LL: Positive pressure on the diaphragm
produces a positive voltage on white lead with
respect to black lead.
Operating Temperature Range: –10° to +60° C
(+14° to +140° F).
PZM
®
-10
PZM-10LL
POLAR
PATTERN
Current drain:
PZM-10: 400 microamperes.
PZM-10LL: 2.8 mA at 12V DC, 4.22 mA at 24V
DC. See Table 1.
Output connectors:
PZM-10: Male XLR type (3-pin pro audio). PZM-
10LL: None.
Cable:
PZM-10: None supplied. Use 2-conductor
shielded mic cable.
PZM-10LL: 12-in., permanently attached 3-con-
ductor shielded cable. Red: B+, White: audio+,
Black: audio–, Shield: ground.
Materials: Steel plate and housing.
Finish: Off-white. May be painted any color; take
care to fi rst seal the opening between the
capsule and boundary plate.
Net weight: PZM-10: 2.6 oz. (73.6 g).
PZM-10LL: 3.3 oz. (93.9 g).
Dimensions: See Fig. 3.
*1 pascal = 10 dynes/cm
2
= 10 microbars = 94 dB SPL.
Features:
• Pressure Zone Microphones for security
and surveillance
• Clear, intelligible pickup of speech
• Choice of mic level output (PZM-10) or
line-level output (PZM-10LL)
• Inconspicous, resembles a light switch
• PZM-10 powered by 12-48V phantom
power
• PZM-10LL powered by 12-24V DC
B+ SENSITIVITY DRAIN
24V 1.4 V/Pa 4.22 mA
20V 1.4 V/Pa 3.00 mA
15V 1.0 V/Pa 2.75 mA
12V 0.9 V/Pa 2.50 mA
Effect of power-supply voltage on
PZM-10LL sensitivity and current drain
Table 1