…for purchasing a JBL Powered Subwoofer.
When used with your current Audio/Home-Theatre system, the JBL subwoofer will deliver all the realism
and excitement present in today’s music and film digital soundtracks.
This subwoofer has been designed to give you many years of trouble-free listening enjoyment. Though easy
to install, we recommend that you read carefully through this instruction manual, and to save your bill
of sale in the unlikely event that your subwoofer requires servicing.
• We recommend that the subwoofer be
unplugged from the wall during lightning
storms, and when not used for an extended
period of time.
• Do not use wherever there is a risk that the
subwoofer may come into contact with water
or excessive moisture such as near pools,
bathtubs and wet basements.
• In the event of a malfunction, do not attempt
to service the product yourself. Please contact
your JBL dealer.
• Before making connections to your receiver or
processor, please make sure the subwoofer is
unplugged from the wall and that your the
audio/video receiver or surround processor is
in off position.
Baie D’Urfé, QC, Canada • H9X 4B7
tel: (514) 457-2555 • fax: (514) 457-0055
© 2003 Jam Industries Ltd.
Low frequency sound is generally non-directional. This allows for great
flexibility in the placing of a subwoofer, as it is difficult for the human
ear to discern where the low frequency sound originates. Ideally,
however, the subwoofer will be placed on the same plane as the main
Bass output varies with position. For more bass output, place the
subwoofer near a wall boundary. Placing the subwoofer closer to
a corner of the room will increase the bass output considerably.
Connecting The Subwoofer
A) Line Level Connection
(also knows as "Low-Level").
Connect the audio/video receiver or processor’s subwoofer output,
to the JBL Subwoofer’s L/R Line Level input. (Optionally, you may
connect your Left/Right speakers as shown below.
Line-Level connection Tip:
Some receivers and processors have a single subwoofer output. In
such cases it is recommended to use a "Y" adapter.
B) Speaker Level Connection
(also knows as "High-Level").
Connect the audio/video receiver’s Left/Right main channel outputs to
the JBL PB8 L/R Speaker Level Inputs. Make sure to connect "+" (Red)
to "+" ( Red), and "-" ( Black) to "-" (Black). (Optionally, you may
connect your Left/Right speakers as shown below.
High-Level connection Tip:
When using small satellite speakers, connecting the JBL subwoofer
with the Speaker Level inputs and then connecting L/R satellites to
the "Speaker out" will automatically limit the low frequency sent to
the small speakers with the high-pass filter built into the JBL
subwoofer. This is helpful to small speakers, in that they will then
not be required to reproduce frequencies that may be beyond their
You may now plug your subwoofer’s power cord to the A/C wall outlet.
You are now ready to use your new JBL subwoofer.
A) On/Off Switch
Your may choose to have your Subwoofer turn
on automatically once it senses an incoming
signal. In that case please select the "Auto"
position on the back of the amplifier. The
amplifier will turn itself off to stand-by mode if it does not sense a
signal after approximately 10 seconds. When listening at very low
levels, the amplifier’s signal may be too low to turn the amplifier on
automatically. In such cases please select the "On" position on the
amplifier. When in the "Off" position the Subwoofer will remain in
stand-by mode and not be triggered by an incoming signal.
The Phase switch allows your subwoofer to
match the output of the bass driver in relation
to the other speakers in the listening room.
The correct position for this switch is
whichever way produces more perceived bass. You may experiment by
switching between 0º and 180º, and determining which position
sounds best. In most cases, however, leaving the switch in the 0º
position will produce the best results.
C) Setting the Volume and Crossover Frequency:
The Crossover Frequency control
determines the frequency below which the
subwoofer will play. This frequency is
manually controlled and is continuously
variable between 60-180Hz. You can
experiment with which position works best
with your main speakers by turning
this control until the sound of the low
frequency coming from the subwoofer is
nicely blended with the sound of your main speakers.
Crossover setting tip:
When using small speakers (speakers with a 6" or less main woofer)
set this control toward the "180" position. When using larger
speakers (speakers with an 8" or more main woofer) set the control
closer to the "60" position.
When setting the volume control at the
subwoofer, begin with your main speakers
playing at a normal listening level and the
volume control at the subwoofer completely
in the off position (counterclockwise
position). Then, begin to turn up the
volume at the subwoofer slowly (clockwise)
until the desired bass response is achieved.
Bass output will then be regulated by your
A/V receiver’s volume control.
Volume setting tip:
Have one person sit at the regular listening position, and a second
person turn up the volume at the subwoofer until the desired bass
output is achieved at the listening position. Remember most natural
sounding bass results when bass reproduction is balanced with the
Do not block the tuned
port: Allow a few inches
of space behind the