Harman JBL CX Series User manual

CX SERIES
CX1200
car audio subwoofer
owner’s manual

2
CHOOSING AN ENCLOSURE
THANK YOU for purchasing a
JBL® CX Series subwoofer.
Subwoofer installation requires
woodworking skills and some
experience in disassembling and
reassembling automotive interiors.
If you lack the tools or necessary
skills, have your subwoofer installed
by an authorized JBL dealer.
WARNING: Playing loud music
in an automobile can permanently
damage your hearing as well as
hinder your ability to hear traffic.
Listening at low levels while driving
is recommended. JBL, Inc., accepts
no liability for hearing loss, bodily
injury or property damage resulting
from use or misuse of this product.
CXSeries subwoofers are optimized
to perform best in small, sealed,
vented and prefabricated band-pass
enclosures. While infinite-baffle
mounting of CXSeries subs is possi-
ble, power handling will be greatly
compromised because there’s no
enclosed volume of air to prevent
the speaker’s cone from moving
past its limit. For this reason, infinite-
baffle mounting is not recommended
for CXSeries subwoofers.
You should choose the enclosure
you will use based on the type of
music you listen to, how much
amplifier power you will use for the
subwoofer and how much space
inside the vehicle you can devote
to a subwoofer enclosure.
Because a sealed enclosure
provides the most control over
the woofer’s movement, a woofer
mounted in a sealed enclosure will
handle more power than a woofer
mounted in another enclosure type.
Sealed enclosures provide more-
accurate sonic reproduction than
other enclosure types when
mounted inside a vehicle, so they
are well suited to all types of music.
Sealed-enclosure construction is
straightforward, and there are many
prefabricated sealed enclosures
available. An optimum sealed
enclosure is always smaller than
other types of enclosures optimized
for a particular speaker, so they
require the smallest amount of
space inside the vehicle.
Vented enclosures provide better
efficiency in the 40Hz – 50Hz range,
but this efficiency comes at the
expense of sound in the lowest
octave (below 40Hz) and at the
expense of some control and power
handling at the lowest frequencies.
If you are using a small amplifier,
avented box will provide more
perceived bass output from less
power. Vented enclosures are also
well suited to a variety of music
types. Because vented enclosures
require the volume of the enclosure
and the size of the port to have
a specific relationship with the
characteristics of the woofer, the
enclosure must be built exactly to
the specifications provided. While
there are some prefabricated
vented boxes available, matching
aprefabricated box to a particular
woofer is difficult. If you wish to
use a vented enclosure, it is strongly
recommended that you have your
authorized JBL dealer build it or
verify that your design is correct
if you wish to build it yourself. An
optimum vented enclosure is always
larger than the optimum sealed box
for the same woofer and will require
more space inside the vehicle.
Band-pass enclosures often provide
the most output available from any
amplifier and subwoofer combination,
at the expense of sonic accuracy.
If sheer SPL (sound-pressure level)
is what you desire most, choose a
band-pass enclosure. Band-pass
enclosure design is very tricky, and
the aid of a computer and enclosure
design software is necessary. If you
are an experienced installer or have
some woodworking experience,
you may wish to build the band-pass
enclosure described in the enclosure
design sheet included with this
woofer. Fortunately, there are many
prefabricated band-pass boxes
available, and they are all optimized
to extract the most output possible
from any woofer. Band-pass
enclosures can be quite large and
may require a lot of space inside
your vehicle.

3
Your CXSeries subwoofer has a
single 4-ohm voice coil. Be sure to
consider your amplifier’s optimum
load when designing a subwoofer
system. Many bridgeable 2-channel
amplifiers are optimized to drive a
single 4-ohm woofer in bridged
mode. If you will use multiple
woofers, be sure to configure them
to extract all the power available
from your amplifier. When designing
a subwoofer system, consider the
following rules:
1. Do not mix different subwoofers
or enclosure types in the same
system. Subwoofers being used in
the same enclosure or powered
by the same amplifier should
be identical models. Mismatched
woofers and enclosures can
result in poor system performance.
2. Most amplifiers deliver exactly
the same amount of power
bridged into a 4-ohm load
as they do driving a 2-ohm
stereo load.
3. If you are designing a multiple-
woofer system, be sure to configure
the woofers so that they each
receive the same amount of
power from the amplifier. Never
connect two identical woofers in
series and then connect that pair
to another woofer in parallel. If
your system will include an odd
number of woofers, be sure to
connect all the woofers in either
series or parallel, according to
the rules that follow, in order to
maximize the power available
from your amplifier:
a. The total system impedance
of voice coils (or woofers) in
series can be calculated using
the formula:
Impedance = w1+ w2+ w3...
b. The total system impedance
of woofers in parallel can be
calculated using the formula:
Impedance = 1
1+1+1...
w1w2w3
where w is the nominal
impedance of the woofer.
The diagrams at right show series
and parallel speaker connections.
Figure 1. Connecting two woofers
in series to the amplifier (8 ohms)
Figure 2. Connecting two woofers in
parallel to the amplifier (2 ohms)
CONNECTING YOUR SUBWOOFER TO YOUR AMPLIFIER
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
Series connection of two woofers (8 ohms)
Parallel Connection of two woofers (2 ohms)
Connection of single woofer (4 ohms)
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
Red
Positive
Black
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
To Amp
Positive
To Amp
Negative
Series connection of two woofers (8 ohms)
Parallel Connection of two woofers (2 ohms)
C g

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SPECIFICATIONS
Power Handling, RMS
Power Handling, Peak
Sensitivity (2.83V/1m)
Frequency Response
Impedance
Mounting Depth
Cutout Diameter
Overall Diameter
GENERAL CARE
The loudspeaker grille may be cleaned with a damp cloth. Do not use any cleaners or solvents on the grille or the speaker cone.
A valid serial number is required for warranty coverage.
Features, specifications and appearance are subject to change without notice.
This product is designed for mobile applications and is not intended for connection to the mains.
Designed and engineered in the USA.
HARMAN International Industries, Inc.
8500 Balboa Boulevard, Northridge, CA 91329 USA
www.jbl.com
© 2014 Harman International Industries, Incorporated. All rights reserved.
JBL is a trademark of Harman International Industries, Incorporated,
registered in the United States and/or other countries.
CX1200
12" (300mm) Subwoofer
250W
1000W
90dB
35Hz – 200Hz
4 Ohms
6-1/16" (153mm)
11" (279mm)
12-1/4" (311mm)