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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. 

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 MR 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).

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.

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 MR Series speakers.

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 MR Center, determine 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

(2 ft. or less)

(2 ft. or less)

Fig. 2

MR Series OM  7/28/98 10:32 AM  Page 3

part of the outer insulation; or a print-
ed “+” marking on one of the insula-
tors. 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.

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.

When connecting the MR Center or
other MR 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
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.

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 

simultane-

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
MR Series loudspeakers, check the
following:

Your amplifier’s 

impedance.

The 

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 MR 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. . .

POWER:
A)100 watts RMS into 8 ohms, both chan-
nels driven, 20-20kHz with less than
0.02%THD

B) 160 watts RMS into 4 ohms, both
channels driven, 20-20kHz with less than
0.02% THD.

Part B indicates that the amplifier can
handle 4-ohm combined impedances
created by two sets of speakers. 

Left 
Speaker

Amplifier/Receiver

Right
Speaker

Red Blk.

(+)

+

+

(–)

Red

R

L

Blk.

(+) (–)

Fig. 3

MR Series OM  7/28/98 10:32 AM  Page 4

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.

Thanks to their high efficiency, the
JBL MR Series Loudspeakers will
produce reasonable volume levels in
a room of moderate size with very lit-
tle 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.

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.

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.

Wrong speaker switch, “A” or  “B”

speaker output.

. Sound source (CD,cassette deck,

turntable) not turned on, not activat-
ed, not hooked up or not selected on
amp/receiver front panel.

No sound from one speaker
1. 

Balance control turned all the way

left or right.

Speaker wire has become discon-

nected.

. One of the connections between

sound source and amp/receiver is
faulty or has  become disconnected.

Both speakers play at low volumes 
but shut off as volume is in-
creased OR sound turns on and 
off intermittently

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
seems to come from each speaker
separately, without creating a 
stable stereo image between the
speakers.

The polarity (+ & –) of one speaker

has been reversed relative to the
other. Double check connections.

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.

Additional Areas to Check When
Using an AV Receiver:
No sound at all or very faint sound
from the center channel or other
speakers

Speaker wire has become discon-

nected.

MR Series OM  7/28/98 10:32 AM  Page 5

. One of the connections between

sound source and AV receiver/amp is
faulty or has  become disconnected.

. AV receiver/amp center channel

mode not selected.  Please select a
mode that activates the center
channel.

Rear/surround information may not

be recorded in some scenes and
passages.

AV receiver/amp “audio direct”

switch is activated.  This switch
should be off to activate the 5 
speaker surround mode.

. 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.

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. 

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.

Should your loudspeaker ever need
service, return it to the JBL dealer
from whom it was purchased. 

If purchased outside the United
States, contact your local distributor
to make arrangements for repair 
service.

MR Series OM  7/28/98 10:32 AM  Page 6