LS120P (120V)
JBL LS SERIES
OWNER’S GUIDE
®
JBLP2555LS120P-120Vom 4/16/08 1:12 PM Page 1
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a dry cloth.
7. Do not block any ventilation openings. Install in accordance
with the manufacturer’s instructions.
8. Do not install near any heat sources such as radiators, heat
registers, stoves or other apparatus (including amplifiers) that
produce heat.
9. Do not defeat the safety purpose of the polarized or grounding-
type plug. A polarized plug has two blades with one wider than
the other. A grounding-type plug has two blades and a third
grounding prong. The wide blade or the third prong is provided
for your safety. If the provided plug does not fit into your outlet,
consult an electrician for replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles and the point
where they exit from the apparatus.
11. Only use attachments/accessories specified by the
manufacturer.
12. Use only with the cart, stand, tripod, bracket or
table specified by the manufacturer or sold with the
apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid
injury from tip-over.
13. Unplug this apparatus during lightning storms or when unused
for long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way, such
as power supply cord or plug is damaged, liquid has been spilled
or objects have fallen into the apparatus, or the apparatus has
been exposed to rain or moisture, does not operate normally or
has been dropped.
15. Do not expose this apparatus to dripping or splashing and
ensure that no objects filled with liquids, such as vases, are
placed on the apparatus.
16. To completely disconnect this apparatus from the AC Mains,
disconnect the power supply cord plug from the AC receptacle.
17. The mains plug of the power supply cord shall remain readily
operable.
18. Do not expose batteries to excessive heat such as sunshine,
fire or the like.
The lightning flash with arrowhead symbol, within
an equilateral triangle, is intended to alert the
user to the presence of uninsulated “dangerous
voltage” within the product’s enclosure that may
be of sufficient magnitude to constitute a risk of electric shock to
persons.
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and mainte-
nance (servicing) instructions in the literature
accompanying the product.
WARNING: To reduce the risk of fire or electric shock, do not
expose this apparatus to rain or moisture.
IMPORTANT SAFETY INSTRUCTIONS
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For more than 60 years, JBL has been providing audio equipment for concert
halls, recording studios and movie theaters around the world, and has become
the hands-down choice of leading recording artists and sound engineers. With
the JBL LS Series, innovative technologies such as pure-titanium compression
drivers, Elliptical Oblate Spheroidal
™
(EOS) waveguides and PolyPlas
™
transducer
reinforcement are available to you. Enjoy!
UNPACKING THE SPEAKERS
If you suspect damage from transit, report it immediately to your dealer.
Keep the shipping carton and packing materials for future use.
PLACEMENT
Since the installation of a subwoofer can be somewhat more complicated
than installation of full-range speakers, it is essential that you read this section
very carefully prior to connecting the subwoofer to your system. Should you
have questions relating to your installation, it is advisable to call your dealer or
distributor for advice.
The performance of the subwoofer is directly related to its placement in the
listening room and how you align the subwoofer with its satellite speakers.
Setting the volume of the subwoofer in relation to the left and right speakers
is
also of critical importance because it is essential that the subwoofer integrate
smoothly with the entire system. Setting the subwoofer’s volume level too high
will result in overpowering, boomy bass. Setting the volume level too low will
negate the benefits of the subwoofer.
Here are several additional facts on installation that may prove useful. It is
generally believed by most audio authorities that low frequencies (below 125Hz)
are nondirectional and, therefore, placement of a subwoofer within any listening
room is not critical. While in theory it is true that the larger wavelengths of
extremely low frequencies are basically nondirectional, the fact is that, when
installing a subwoofer within the limited confines of a room, reflections, standing
waves and absorptions generated within the room will strongly influence the
performance of any subwoofer system. As a result, specific location of the
subwoofer becomes important, and we strongly recommend that you experiment
with placement before choosing a final location.
Placement will depend upon your room and the amount and quality of bass
required (for example, whether or not your room permits placement of the
subwoofer near either satellite).
Figure 1. This example shows the subwoofer positioned behind
the right-channel satellite speaker to re-create the actual location
of bass instruments in an orchestra and/or add impact to movie
soundtracks.
JBL
®
LS120P POWERED SUBWOOFER
3
INSTALLING SPIKED FEET
Four metal spikes are supplied for use when the speaker is to be placed on a
carpeted surface; using them decouples the speaker from the floor to prevent
unwanted damping. To insert the spikes, gently lay the speaker on its side (not
its front or back) on a soft, nonabrasive surface, and unscrew the rubber-tipped
feet (store in a safe place). Each spike then screws into the threaded insert in
each corner. Make sure all four spikes are screwed in completely for stability.
To protect the surface of uncarpeted floors, set each spike into an included
metal coaster.
NEVER drag the speaker to move it, as this will damage the spikes, the feet, the
wood cabinet itself, and/or the floor. Always lift the speaker and carry it to its new
location.
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4
REAR PANEL
CONTROLS AND CONNECTIONS
LS120P
0
Phase Switch
1
LFE/Normal Selector
2
Subwoofer-Level Control
3
Crossover Adjustment
4
Power Indicator
5
Line-Level/LFE Input
6
Power Switch
0
1
2
5
6
3
4
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SYSTEM CONNECTIONS
If you have a Dolby
®
Digital or DTS
®
receiver/processor
with a low-frequency-effects (LFE) or subwoofer output:
5
If your receiver/processor does not contain a Dolby Digital or DTS
processor, but has subwoofer outputs:
Set LFE/Normal switch to
“Normal.”
NOTE: If your receiver/processor
has only one sub out, you may
use either the L or R input.
LS120P
LS120P
Set LFE/Normal switch to “LFE.”
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POWER ON
Plug your subwoofer’s AC cord into a wall outlet. Do not use the outlets on the
back of the receiver.
Initially set the Subwoofer-Level Control
£
to the “Min” position.
Turn on your sub by pressing the Power Switch
¶
on the rear panel.
Turn on your entire audio system and start a CD or movie soundtrack at
a moderate level.
AUTO ON/STANDBY
With the Power Switch
¶
in the “On” position, the Status LED
∞
on the
back will remain lit in red or green to indicate the On/Standby mode
of the subwoofer.
RED = STANDBY (no signal detected, Amp Off)
GREEN = ON (signal detected, Amp On)
The subwoofer will automatically enter the Standby mode after approximately
10 minutes when no signal is detected from your system. The subwoofer will
then power ON instantly when a signal is detected. During periods of normal
use, the Power Switch
¶
can be left on. You may turn off the Power Switch
¶
for extended periods of nonoperation, e.g., when you are away on vacation.
GETTING STARTED
Turn your Subwoofer-Level Control £ up to the halfway position. If no sound
emanates from the subwoofer, check the AC-line cord and input cables. Are the
connectors on the cables making proper contact? Is the AC plug connected to
a “live” receptacle? Has the Power Switch
6
been pressed to the “On” position?
Once you have confirmed that the subwoofer is active, proceed by playing a
CD, record or cassette. Use a selection that has ample bass information.
ADJUST LEVEL
Set the overall volume control of the preamplifier or stereo to a comfortable
level. Adjust the Subwoofer-Level Control £ until you obtain a pleasing blend
of bass. Bass response should not overpower the room but rather be adjusted
so there is a harmonious blend across the entire musical range. Many users
have a tendency to set the subwoofer volume too loud, adhering to the belief
that a subwoofer is there to produce lots of bass. This is not entirely true.
A subwoofer is there to enhance bass, extending the response of the entire
system so the bass can be felt as well as heard. However, overall balance
must be maintained or the music will not sound natural. An experienced
listener will set the volume of the subwoofer so its impact on bass response
is always there but never obtrusive.
PHASE CONTROL
The Phase Switch ¡ determines whether the subwoofer speaker’s pistonlike
action moves in and out with the main speakers, 0˚, or opposite the main
speakers, 180˚. Proper phase adjustment depends on several variables such
as room size, subwoofer placement and listener position. Adjust the phase
switch to maximize bass output at the listening position.
CROSSOVER ADJUSTMENT
The Crossover Adjustment Control ¢ determines the highest frequency at
which the subwoofer reproduces sounds. If your main speakers can comfortably
reproduce some low-frequency sounds, set this control to a lower frequency
setting, between 50Hz and 100Hz. This will concentrate the subwoofer’s
efforts on the ultradeep bass sounds required by today’s films and music.
If you are using smaller bookshelf speakers that do not extend to the lower
bass frequencies, set the Crossover Adjustment control to a higher setting,
between 120Hz and 150Hz.
NOTE: This control will have no effect if the LFE/Normal Selector ™ is set
to LFE. If you have a Dolby Digital or DTS processor/receiver, the Low-Pass
Frequency is set by the processor/receiver. Consult your owner’s manual
to learn how to view or change this setting.
The enclosure may be cleaned using a soft cloth to remove fingerprints or to
wipe off dust.
The grille may be gently vacuumed. Stains may be removed with an aerosol
cleaner, following its instructions. Do not use any solvents on the grille.
All wiring connections should be inspected and cleaned or remade periodically.
The frequency of maintenance depends on the metals involved in the connections,
atmospheric conditions and other factors, but once per year is the minimum.
In the event that your subwoofer ever needs service, contact your local JBL
dealer, or visit www.jbl.com for a service center near you.
OPERATION
6
MAINTENANCE AND SERVICE
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SPECIFICATIONS
LS120P
Frequency Response 25Hz – 150Hz
Amplifier RMS Power 400 Watts
Amplifier Peak Dynamic Power
†
700 Watts
Crossover Frequency 50Hz – 150Hz;
24dB/octave, continuously adjustable
Driver 12" (300mm) PolyPlas™
Dimensions (H x W x D) 19-7/16" x 14-3/4" x 16-3/4"
(enclosure only) (493mm x 375mm x 425mm)
Dimensions (H x W x D) 20-1/16" x 14-3/4" x 17-1/4"
(with feet, controls, grille, etc.) (510mm x 375mm x 438mm)
Weight 57 lb (25.8kg)
†
The peak dynamic power is measured by recording the highest center-to-peak
voltage measured across the output of a resistive load equal to minimum impedance
of the transducer, using a 50Hz sine wave burst, 3 cycles on, 17 cycles off.
JBLP2555LS120P-120Vom 4/16/08 1:12 PM Page 7
Features, specifications and appearance are subject to change without notice.
JBL is a trademark of Harman International Industries, Incorporated, registered in the
United States and/or other countries. Elliptical Oblate Spheroidal, PolyPlas and Pro Sound
Comes Home are trademarks of Harman International Industries, Incorporated.
Dolby is a registered trademark of Dolby Laboratories.
DTS is a registered trademark of DTS, Inc.
®
PRO SOUND COMES HOME
™
Harman Consumer Group, Inc., 250 Crossways Park Drive, Woodbury, NY 11797 USA
8500 Balboa Boulevard, Northridge, CA 91329 USA
www.jbl.com
© 2008 Harman International Industries, Incorporated. All rights reserved.
Part No.
406-000-05777-E
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