
SpeakerS
SI 3CT LP
FULL-RANGE CEILING SPEAKERS WITH
4" LOW PROFILE BACK CAN AND TRANSFORMER
n 3" (7.6 cm) full-range driver with a
tuned port
n 4" (10.2 cm) deep low profile metal
back can for plenum environments
n Wide 170˚ conical dispersion
n 8 ohm direct, 70 volt, and
100 volt operation
n 6 position, behind-the-grille
power selector
n 16 watts continuous pink noise,
32 watts continuous program
n Locking arms for quick ceiling
installation
n UL plenum rated
n Includes C-ring & V-rail kit
n 5 year parts and labor warranty
The Extron SI 3CT LP is a full-range ceiling speaker featuring a low profile back
can and transformer. A full-range driver, coupled to an exclusive conical baffle
delivers very wide room coverage as well as wide frequency response for accurate
voice and music reproduction. This System Integrator® Series speaker is ideally
suited for small to medium classrooms with lower ceilings and low to medium
power requirements.
www.extron.com

DESCRIPTION SPECIFICATIONS
Front View
Side View
Rear View
Isometric View
9.88"
(25.1 cm)
8.39"
(21.3 cm)
8.77"
(22.3 cm)
4.00"
(10.2 cm)
0.57"
(1.44 cm)
The Extron SI 3CT LP is a full-range ceiling speaker featuring a 4" (10.2 cm)
LP - Low Profile metal back can for use in plenum ceilings. The low profile
speaker is an excellent choice for ceiling installations with tight above-theceiling tile space issues, such as air handling units installed close to the
ceiling. The 3" (7.6 cm) full-range driver features an incredibly wide frequency
response of 75 Hz to 17 kHz, 16 watts continuous pink noise or 32 watts
continuous program capacity, and an extremely wide conical dispersion of
170°. The SI 3CT LP is ideal for small to medium classrooms with lower ceilings
and low to medium power requirements.
The SI 3CT LP features an exclusive conical baffle that provides a wider room
coverage pattern, which is important for rooms with low ceilings. This design
reduces “beaming” of mid and high frequencies directly under the speaker.
Voice intelligibility is critical for classrooms and many other applications, and
the SI 3CT LP provides excellent voice clarity without compromising music
reproduction.
The SI 3CT LP offers both direct 8 ohm or 70/100 volt operation with a
behind-the-grille, six position power selector switch. In the 8 ohm direct
position, this speaker is designed for use with our MPA 122 Integrated Mini
Power Amplifier in small to medium low ceiling classrooms requiring two to
four wide dispersion speakers for maximum room coverage.
Many system designers desire 70/100 volt operation for multiple speakers
and long speaker wire runs when the amplifier is remotely located. For small
to medium classrooms, the SI 3CT LP is designed for use with the MPA 181T
70 volt Integrated Mini Power Amplifier. For room balancing with 70/100 volt
systems, the behind-the-grille power selector switch allows for 16, 8 ,4, 2, and
1 watt settings in 70 volt operation and 16, 8, 4, and 2 watt settings for
100 volt operation.
Four locking arms allow for a fast, secure hard ceiling installation. The
SI 3CT LP includes mounting hardware to facilitate installation in a suspended
T-bar ceiling. It features a white grille and bezel that can be painted to match
the architectural elements of the environment.
FEATURES
n 4" (10.2 cm) deep low profile metal back can for plenum environments
n 3" (7.6 cm) full-range driver with a tuned port
n 8 ohm direct or 70/100 volt operation on a 6 position,
behind-the-grille selector:
- 8 ohm direct
- 70 volt: 16, 8, 4, 2, and 1 watt selectable
- 100 volt: 16, 8, 4, and 2 watt selectable
n Frequency response: 75 Hz to 17 kHz
n 16 watts continuous pink noise, 32 watts continuous program
n 170° conical dispersion
n Locking arms for quick ceiling installation
n UL plenum rated
n Includes C-ring & V-rail kit
n Grille and bezel are available in white only and may be painted
to match environment
n 5 year parts and labor warranty
Audio/Acoustic And electricAl
Speaker type ................................... Low profile ceiling speaker with metal
back can
Frequency response ........................ 75 Hz to 17 kHz, -10 dB, half space
Power capacity ................................ 16 W continuous pink noise
32 W continuous program
Nominal sensitivity .......................... 83 dB SPL, 1 W, 1 m, 16 W tap, half space
Nominal coverage angle ................. 170° conical coverage
Nominal impedance ....................... 8 ohms
Rotary switch taps ........................... 70V: 16 W, 8 W, 4 W, 2 W, 1 W
100 V: null, 16 W, 8 W, 4 W, 2 W
Driver .............................................. 3" (76 mm) paper cone
Input connector ............................. (1) 5 mm captive screw connector, 4 pole
for 1 input and 1 loop-through
GenerAl
Package .......................................... 2 speakers (1 pair)
Temperature/humidity .................... Storage: -40 to +158 °F (-40 to +70 °C) /
10% to 90%, noncondensing
Operating: +32 to +122 °F (0 to +50 °C) /
10% to 90%, noncondensing
Mounting ........................................ Ceiling mountable with included hardware:
V-rails for 2' x 4' (600 mm x 1200 mm)
ceiling tiles, and C-rings
Enclosure type ................................ Metal back can; high-impact, fire-resistant
(UL94V-0) plastic baffle/rim
Enclosure outer dimensions ............ 4.0" H x 9.9" diameter
(102 mm x 251 mm diameter)
Cutout dimensions .......................... 8.937" diameter (227 mm diameter)
Product weight ............................... 6 lbs (2.7 kg) each
Shipping weight ............................. 22 lbs (10 kg) per pair with mounting kit
package
Listings ............................................ UL 2043, UL1480
Compliances ................................... CE, NFPA90, NFPA70A
Warranty ........................................ 5 years parts and labor
NOTE: All nominal levels are at ±10%.
Model Version Description Part Number
SI 3CT LP Ceiling Speakers - 4" Back Can, Pair ................ 42-103-03
DIMENSIONAL DRAWINGS

Ceiling Deck
Suspended Ceiling
SI 3CT LP
Full-Ra nge Ceiling
Speakers with
4" Low Prole Back
Can and Transformer
SI 3CT LP
Full-Ra nge Ceiling
Speakers with
4" Low Prole Back
Can and Transformer
HVAC Ducting
Shallow Plenum Return Air Space
Room Air Flow
Fire Sp rinkler Piping
FEATURES
Conical Baffle
In small to medium-sized classrooms with low
ceilings, midrange and high frequencies are
likely to be confined or "beamed" within an area
directly beneath each ceiling speaker. As a result,
some listeners will hear the audio clearly while
others may not.
To address this issue, the SI 3CT LP has been
designed with a 3" full-range driver that is
acoustically coupled to an Extron exclusive conical
baffle. This baffle serves as a waveguide to help
create a wide dispersion profile of 170°. With this
very broad conical spreading of the mid and high
frequencies, a system of SI 3CT LP speakers will
ensure consistent volume levels for everyone in the
room while delivering increased intelligibility and
accurate music reproduction.
8" Back Can
Back Can
4" Low Profile
SI 26CT
Two-Way Ceiling Speakers with
8" Back Can and Transformer
Full-Range Ceiling Speakers with 4" Low
SI 3CT LP
Profile Back Can and Transformer Can
Low Profile Back Can
The SI 3CT LP features a special 4" low profile back can for installation in plenum ceilings where the presence of HVAC ducting, fire
sprinkler piping, or limited spacing above the suspended ceiling would hamper placement of a ceiling speaker with a more conventional
back can such as the SI 26CT. The specially designed 3" full-range driver of the SI 3CT LP works together with the low profile back
can to deliver wide frequency response as well as wide conical dispersion for optimal sound reproduction in classrooms and other
environments.

20 Hz 50 100 200 500 1K 2K 5K 10K 20
dBSPL
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40
50
60
70
80
90
100
0 Degrees
10 Degrees
20 Degrees
30 Degrees
40 Degrees
20 Hz 50 100 200 500 1K 2K 5K 10K 20
dBSPL
20
30
40
50
60
70
80
90
100
20 Hz 50 100 200 500 1K 2K 5K 10K 20
RESPONSE GRAPHS – FREQUENCY AND IMPEDANCE
SPL VS. FREQUENCY – 1 WATT @ 1 METER RESPONSE, HALF SPACE (2π)
SPL VS. FREQUENCY – HORIZONTAL OFF-AXIS RESPONSE, HALF SPACE (2π)
IMPEDANCE VS. FREQUENCY

Extron Electronics, Europe
Beeldschermweg 6C, 3821 AH Amersfoort
The Netherlands
+800.3987.6673 +31.33.453.4040
FAX +31.33.453.4050
Extron Electronics, Asia
135 Joo Seng Rd. #04-01
PM Industrial Bldg.
Singapore 368363
+65.6383.4400 FAX +65.6383.4664
Extron Electronics, Japan
Kyodo Building, 16 Ichibancho
Chiyoda-ku, Tokyo 102-0082
Japan
+81.3.3511.7655 FAX +81.3.3511.7656
Extron Electronics, USA
1230 South Lewis Street
Anaheim, CA 92805
800.633.9876 714.491.1500
FAX 714.491.1517
SURFACE SPEAKERS
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SI 28
8" (20.3 cm) Woofer
1" (2.5 cm) Tweeter
50 Hz to 20 kHz
180 Watts Cont. Prog.
CEILING SPEAKERS
SI 26CT
6.5" (16.5 cm) Woofer
1" (2.5 cm) Pivoting Tweeter
70 Hz to 20 kHz
150 Watts Cont. Prog.
Plenum Rated 8" Back Can
IN WALL SPEAKERS
SI 26
6.5" (16.5 cm) Woofer
1" (2.5 cm) Tweeter
70 Hz to 20 kHz
150 Watts Cont. Prog.
SI 3CT LP
3" (7.6 cm) Full Range
75 Hz to 17 kHz
32 Watts Cont. Prog.
Plenum Rated 4" Back Can
SI 3
3" (7.6 cm) full range
75 Hz to 17 kHz
32 Watts Cont. Prog.
SI 26X
6.5" (16.5 cm) Woofer
50 Hz to 20 kHz
50 Watts Cont. Prog.
© 2007 Extron Electronics. All rights reserved. All trademarks mentioned are the property of their respective owners.
SI 28W
8" (20.3 cm) Woofer
1" (2.5 cm) Tweeter
30 Hz to 20 kHz
70 Watts Cont. Prog.
SI 26W
6.5" (16.5 cm) Woofer
.75" (1.9 cm) Tweeter
40 Hz to 20 kHz
60 Watts Cont. Prog.
07-05
68-1158-01
REV. C