
Industrial/Institutional Surface
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Surface- mount speaker system built to sur vive 
harsh treatment of industrial/institutional use.
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Sturdy spin-formed steel housing is protected 
by a non- glare white baked powder coat finish.
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Rugged integral compression driver for noise 
penetration and speech intelligibility.
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16 watts continuous duty, 500 Hz to 7000 Hz 
frequency range.
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25/70 volt line Model IS4T16 has taps at 
16, 8, 4 & 2 watts.
Mount Speaker System
for Voice Communications
IS4 Series
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45 ohm Model IS445 has excellent sensitivity 
as a microphone in talk-back systems.
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Versatile mounting allows surface conduit or 
in-wall electrical box wiring.
MODEL RATED WT.
NO. INPUT WATTS IMPEDANCE (lbs.)
IS445 45 ohms 16 45 ohms
IS4T16 25 V line 39,78,156,312
16,8,4,2 5.5
70 V line 312,625,1250,2500
POLAR PLOT
INPUT TAPS
5
RESPONSE CURVE
- -
 

Industrial/Institutional Surface Mount Speaker System     IS4 Series
TECHNICAL SPECIFICATIONS
Power Handling: 16 watts continuous duty. 
Frequency Range: 700-6500 Hz (±3 dB)
(On Axis) 500-7000 Hz (±6 dB)
Sound Pressure: (1 octave at 2 kHz; at 1 M)
105 dB at 1 watt; 117 dB at 16 watts. 
Talk-Back Sensitivity: (Model IS445) 
Ref 94 dB (1.0 Pa) SPL 700-2000 Hz; 
28.6 ± 1 mv or –17.4 dBm (0 dBm = 1 mw).
PHYSICAL SPECIFICATIONS
Materials: Enclosure and base; 18 gauge 
steel spin-formed to shape. Speaker; high 
impact ABS horn and high stability polycarbonate 
driver components.
Finish: White textured urethane powder coat full 
coverage for maximum corrosion protection and 
long lasting appearance.
Speaker: Enclosure unit has built in compression driver type horn speaker. Replaceable 
phenolic diaphragm is driven by a rugged high 
power 1-1/2⬙ voice coil. Magnet structure steel 
parts are plated per Mil. Spec. QQ-Z-325, 
type I, class 2, passes 96 hour salt spray test.
Mounting Provisions: Base may be anchored 
directly to wall with screws as large as 1/4⬙, or 
to recessed standard 4 ⬙ square or octagon 
electrical box.
Wiring: Access through back for outlet box or 
hidden cable, or through side via one of four 
standard K.O.s for surface mounted conduit or 
cable. Turn enclosure on base to expose desired 
side K.O. entry. Wire directly to speaker or to 
transformer leads.
Fasteners: Enclosure assembly secured to base 
with four #10 stainless steel hex button head 
machine screws. Use standard 1/8⬙ hex driver.
ARCHITECT’S & ENGINEER’S SPECIFICATIONS
The Industrial/Institutional surface mount speaker 
system shall consist of a round enclosure and base 
unit with integral compression driver horn speaker for 
voice communications. Enclosure and base shall be 
18 gauge steel spin-formed and protected overall by 
a baked on powder coat urethane finish. The base 
shall have provisions for attachment to a common 4⬙ 
recessed outlet box or to be fastened directly to a 
wall by screws as large as 1Ⲑ4⬙. Wiring shall enter 
through back for hidden cable or via one of four side 
entry K.O.s for surface cable or 1Ⲑ2⬙ conduit. The 
enclosure shall attach to the base with (4) #10 stainless steel hex drive screws. Color shall be UV stable 
White with a textured finish.
Frequency response shall be 500 to 7000 Hz, on 
axis. SPL at 16 watt input at 1 meter shall be 117 
dB. Power handling capability shall be 16 watts 
continuous duty.
The speaker system in compliance with this specification is Model IS445 (45 ohm impedance) or 
Model IS4T16 (25 or 70 volt audio line).