English
For more than 60 years, JBL has been providing audio equipment to
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-titani-
um compression tweeters, Elliptical Oblate Spheroidal
™
(EOS) wave-
guides and PolyPlas
™
transducer reinforcement are available to you.
Enjoy!
UNPACKING THE SUBWOOFER
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
relationship 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 sound-
tracks.
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 sta-
bility. 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.
JBL® LS120P POWERED SUBWOOFER
3
0012CSK - JBL LS120P OM UK v2.qxp:v 14/01/08 17:12 Side 3
