J SERIES
LOUDSPEAKERS
OWNER’S
MANUAL
J 50
J 520M
J 620M
J 820M
J 830M
J 900MII
J 1000MII
J Center
J
S E R I E S
J SERIES LOUDSPEAKERS
them, at the listening position, is
between 40 and 60 degrees. For
example, if your listening position is
8 to 12 feet (2.5m to 4m) from each
speaker, the two systems should be
about 8 feet (2.5m) apart.
CONNECTIONS
To connect the loudspeaker systems
to the receiver or amplifier, use two-
conductor insulated wire. Your JBL
dealer can recommend suitable
cables, or you can buy wire at most
hardware or electronic stores. We
recommend #16 AWG wire as a mini-
mum size. If your speaker is more
than 30 feet (10m) from your receiver
or amplifier, use larger diameter
lower gauge wire. Connections are
made at the terminals located on the
back of the J Series speakers.
Center Channel Model: As the
center channel contains the dialog
and other central action sounds, the
speaker should be located very close
to the Monitor/TV and centered with
the Monitor/TV’s center line. Place
the J Center directly on top of or
directly below the Monitor/TV with the
front edge of the speaker grille flush
with the edge of the Monitor/TV. You
should have your Left and Right
speakers within a 2 ft or less height
range of your Center Channel for
proper sonic performance (see Fig. 2).
Preparing the Hookup Wire
Carefully plan your w ire lengths
before cutting any speaker w ire.
Be sure to allow plenty of extra
w ire to help hide paths in corners,
along baseboards, etc.
In Case Color Interference Occurs:
The speaker is shielded to work with
video applications, however some
color interference may be observed
on the TV screen depending on the
type of your TV set. If color interfer-
ence is observed, turn your TV off for
15 minutes and move the speaker
back about 1" from the front edge of
the TV. Turn on TV and recheck. If
this is not far enough, move back fur-
ther and experiment until the interfer-
ence disappears. You may have to
turn the TV off for a few minutes and
turn it on again to clear the screen.
1. For Left and Right Speakers, first
determine the wire length needed
between the most distant speaker
and the receiver or amplifier.
2. Now make the hookup wires for
both speakers this length, even if one
loudspeaker is much closer to your
amplifier than the other. This will
help maintain proper signal balance.
(For the J Center, determ ine the
length needed from AV receiver’s
center channel output to speaker).
3. Strip off 3⁄8" of insulation from both
ends of each conductor.
4. Twist each set of thin wires into a
tightly-bunched spiral.
5. At this point you need to identify a
visual difference between the two
conductors of each molded pair of
speaker wire. Differentiating marks
can be a different color wire (copper
or “silver”); a strand of yarn in one
conductor; thin, raised ribs on one
Fig. 2
3
part of the outer insulation; or a
printed “+” marking on one of the
insulators. It does not make any
difference which of the two strands of
wire go to (+) and (–) on the speakers
and amplifier, as long as all speakers
used in your system are connected
identically. Push down on the button
below the terminal and insert the wire
through the hole.
from each speaker. The use of the
“test tone” and the controls on your
AV receiver will enable you to cor-
rectly balance the level (volume) of
sound coming from each speaker in
your Dolby Pro-Logic application.
Hooking Up Multiple Sets
of Speakers
If your receiver has two complete
sets of speaker terminals (“A” and
“B”), it’s possible to hook up an addi-
tional pair of speakers for sim ultane-
ous sound in another room. However,
some speakers may not be usable as
a second pair if you want to play two
sets at once. Before hooking up
another set of speakers besides your
J Series loudspeakers, check the
following:
For each channel, the red terminal on
all loudspeakers should be connected
to the red or (+) speaker connection
terminal on the receiver or amplifier,
and the black to black or (–) speaker
connection terminal (see Fig. 3).
Connecting the loudspeakers in this
manner ensures that they will be in
phase; that is, work together rather
than in opposition. This is very
important when connecting sev-
eral speakers together in a Dolby
Pro-Logic AV application. Connecting
the loudspeakers out of phase will
not damage them, but will result in
less bass and poor imaging.
1 . Your amplifier’s m inim um load
impedance.
2 . The nom inal im pedance of the
second set of speakers. Both of
these specifications are expressed in
ohms and both can be found in the
owner’s manuals which came with
your speakers and amp/receiver. The
receiver’s minimum load impedance
is determined by whether or not
power ratings are given for 4 ohms.
This is because two sets of 8 ohm
speakers will present a 4 ohm load to
the receiver. The J speaker, when
combined with an 8 ohm speaker,
produces an impedance sufficiently
close to 4 ohms. For example, the
following entry in an amplifier owner’s
manual...
Left
Right
Speaker
Speaker
Red Blk.
(+) (–)
Red Blk.
(+) (–)
Fig. 3
+
+
L
R
Am plifier/Receiver
POWER:
A)100 watts RMS into 8 ohms, both chan-
nels driven, 20-20kHz with less than
0.02%THD
When connecting the J Center or
other J Series speakers to a Dolby
Pro-Logic AV receiver, refer to the
instructions accompanying your AV
component for use of the “test tone”
to properly balance the sound output
B) 160 watts RMS into 4 ohms, both
channels driven, 20-20kHz with less than
0.02% THD.
4
J SERIES LOUDSPEAKERS
Part B indicates that the amplifier can
handle 4-ohm combined impedances
created by two sets of speakers.
If only an 8-ohm rating is given, the
amp/receiver may or may not be
designed to handle 4-ohm combined
ratings. Consult the owner’s manual
of the amp/receiver for clarification.
No sound at all or very faint sound
from both speakers
1. Amp/receiver tape monitor button
pushed in while using CD, FM or
phono inputs.
2. Wrong speaker switch, “A” or “B”
speaker output.
3. Sound source (CD, cassette deck,
turntable) not turned on, not activated,
not hooked up or not selected on
amp/receiver front panel.
POWER HANDLING
Thanks to their high efficiency, the
JBL J Series Loudspeakers will pro-
duce reasonable volume levels in a
room of moderate size with very little
amplifier power. However, using a
small amplifier to obtain the desired
volume listening levels may lead to
overdriving the amplifier. This will
generate high distortion levels and
may cause damage to your loud-
speaker. For the best performance,
an amplifier should be selected with
an output rating that is greater than
the maximum power that will be
used. This margin of reserve power
will ensure that the amplifier will not
attempt to deliver more power than
its design allows. However, the
amplifier’s power rating per channel
must not exceed the maximum rec-
ommended amplifier power for that
specific loudspeaker model. Please
see the specification section for
details. Following these guidelines
will provide virtually distortion-free
sound reproduction and long loud-
speaker life.
No sound from one speaker
1. Balance control turned all the way
left or right.
2. Speaker wire has become discon-
nected.
3. One of the connections between
sound source and amp/receiver is
faulty or has become disconnected.
Both speakers play at low volum es
but shut off as volum e is in-
creased OR sound turns on and
off interm ittently
A few strands of speaker wire may
be shorting out. Recheck the con-
nections. Recheck the impedance of
the amp.
Bass is very weak AND/OR sound
seem s to com e from each speaker
separately, without creating a
stable stereo im age between the
speakers.
1. The polarity (+ & –) of one speaker
has been reversed relative to the
other. Double check connections.
TROUBLESHOOTING
The vast majority of new speaker
“malfunctions” end up being traced to
connections or switch settings. To
avoid packing up correctly functioning
speakers and sending them off, only
to find that they’re not really at fault,
check the following tips first, before
requesting service.
2. Speakers are too far away from
back and side walls or too far apart.
Experiment again with the speaker
placement. If you are still encounter-
ing problems, consult your JBL
dealer.
5
Additional Areas to Check When
Using an AV Receiver:
No sound at all or very faint sound
from the center channel or other
speakers
The loudspeaker cabinet may be
cleaned with a slightly damp cloth. To
remove dust from the grille cloth, use
a vacuum with a brush attachment.
Spots may be removed with a com-
mercial spot remover. Do not use any
cleaners or solvents on the speaker
drivers themselves.
1. Speaker wire has become discon-
nected.
2. One of the connections between
sound source and AV receiver/amp is
faulty or has become disconnected.
SERVICE
Should your loudspeaker ever need
service, return it to the JBL dealer
from whom it was purchased. If pur-
chased outside the United States,
contact your local distributor to make
arrangements for repair service. Do
not return products to the J BL fac-
tory w ithout prior authorization.
3. AV receiver/amp center channel
mode not selected. Please select a
mode that activates the center
channel.
4. Rear/surround information may not
be recorded in some scenes and
passages.
5. AV receiver/amp “audio direct”
switch is activated. This switch
should be off to activate the 5
speaker surround mode.
6. Sound source (VDP, VCR, CD,
cassette deck, turntable) not turned
on, not activated, not hooked up or
not selected on AV receiver/amp
front panel.
GENERAL CARE
The grille is held in place by pins
near the edges. To remove the grille,
grasp it by both top and bottom
edges and pull gently. To replace
grille, re-position it carefully and
press gently at the corners. Do not
push on the center area of the grille.
NOTE: The J 50 grille is non-
rem ovable. Do not attem pt to pry
the grille from the cabinet as this
w ill void your w arranty. The rear
panels are rem ovable to allow ser-
vice personnel access to the driver
com ponents if needed.
6
J SERIES LOUDSPEAKERS
Specifications
J Center
J50
J520M
J620M
Application
Center
Bookshelf
Bookshelf
Bookshelf
Channel
High Frequency
Dome Transducer
10mm Ti
Composite
2" Paper
(Cone)
10mm Ti
Composite
10mm Ti
Composite
Midrange Transducer
n/a
n/a
n/a
n/a
(Nitrile Polymer Fibre Cone)
Low Frequency Transducer
(Nitrile Polymer Fibre Cone)
2 x 3.5"
(Neo Magnet)
5"
5"
61⁄2
"
Crossover Frequency
4.5kHz
2.2kHz
4.5kHz
4.5kHz
Frequency
Response (– 6 dB)
80 Hz to
20 kHz
75 Hz to
20 kHz
70 Hz to
20 kHz
55 Hz to
20 kHz
Sensitivity (1 Watt/1 Meter)
Nominal Impedance
87 dB
86 dB
87 dB
88 dB
8 ohms
8 ohms
8 ohms
8 ohms
Recommended
Amplifier Power*
10 to 80
Watts
10 to 50
Watts
10 to 75
Watts
10 to 100
Watts
External Dimensions
Height
Width
53⁄16"
11"
12"
15"
141⁄4
"
61⁄2
"
71⁄2
"
81⁄2
"
Depth
65⁄8
"
71⁄4
"
81⁄2
"
10"
External Dimensions
Height
Width
132 mm
362 mm
168 mm
280 mm
165 mm
184 mm
305 mm
190 mm
216 mm
381 mm
216 mm
254 mm
Depth
Weight (each)
7 lbs
3.2 kg
7 lbs
3.2 kg
8 lbs
3.6 kg
12 lbs
5.5 kg
Shipping Weight
10 lbs
4.5 kg
18 lbs
8.2 kg
20 lbs
9.1 kg
28 lbs
12.7 kg
*The maximum recommended amplifier power rating will insure proper system headroom to allow
for occasional program peaks. We do not recommend sustained operation at these maximum
power Levels.
7
J SERIES LOUDSPEAKERS
Specifications
J820M
J830M
J900MII
J1000MII
Application
Bookshelf
Bookshelf
Tower
Tower
High Frequency 14mm" Ti
Dome Transducer
14mm Ti
Composite
14mm Ti
Composite
14mm Ti
Composite
14mm Ti
Composite
Midrange Transducer
n/a
61⁄2
"
61⁄2
"
61⁄2
"
(Nitrile Polymer Fibre Cone)
Low Frequency Transducer
(Nitrile Polymer Fibre Cone)
8"
8"
8"
10"
Crossover Frequency
3.5kHz
3.5kHz
3.5kHz
3.5kHz
Frequency
Response (– 6 dB)
50 Hz to
20 kHz
45 Hz to
20 kHz
42 Hz to
20 kHz
40 Hz to
20 kHz
Sensitivity (1 Watt/1 Meter)
Nominal Impedance
90 dB
92 dB
92 dB
92 dB
8 ohms
8 ohms
8 ohms
8 ohms
Recommended
Amplifier Power*
10 to 125
Watts
10 to 150
Watts
10 to 150
Watts
10 to 175
Watts
External Dimensions
Height
Width
191⁄4
10"
10"
"
24"
10"
12"
323⁄16"
10"
12"
36"
113⁄4
"
Depth
12"
External Dimensions
Height
Width
489 mm
254 mm
254 mm
610 mm
254 mm
305 mm
818mm
254 mm
305 mm
915 mm
298 mm
305 mm
Depth
Weight (each)
18 lbs
8.2 kg
25 lbs
11.3 kg
28 lbs
12.7 kg
32 lbs
14.5 kg
Shipping Weight
40 lbs
18.2 kg
29 lbs
13.2 kg
32 lbs
14.5 kg
36 lbs
16.4 kg
*The maximum recommended amplifier power rating will insure proper system headroom
to allow for occasional program peaks. We do not recommend sustained operation at
these maximum power Levels.
JBL continually strives to improve its products. New materials, production methods and design refinements are
introduced into existing models without notice as a routine expression of our design philosophy. For this reason,
JBL J Series Loudspeakers may differ in some respect from their published specifications and descriptions, but
will always equal or exceed the original specifications unless otherwise stated.
250 Crossways Park Drive, Woodbury, NY 11797
8500 Balboa Blvd., Northridge, CA 91329
Part No. 332373-001
A Harman International Company
Printed in Taiwan
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