CF-Owner's Manual 7/28/98 9:51 AM Page 3
CF SERIES LOUDSPEAKERS
1.Your receiver or amplifier minimum loadTROUBLESHOOTING
impedance. Impedance is always expressedMost "malfunctions" end up being traced
in ohms and can be found in the owner'sto connections or switch settings. To
manual that came with your unit. For avoid packing up correctly functioning
example, the following are typical entries speakers and sending them off, only to
in receiver/amplifier owner's manuals:find that they're not really at fault, check
A.100 watts RMS into 8 ohms, boththe following tips first, before requesting
channels driven, 20 � 20kHz with less service.
than 0.02%THD
No sound at all or very faint sound
B. 160 watts RMS into 4 ohms, both
from both speakers
channels driven, 20 � 20kHz with less
1. Amp/receiver tape monitor button
than 0.02% THD.
pushed in while using CD, FM or phono
2.The nominal impedanceof the sec-
inputs.
ond set of speakers. A pair of CF Series
2.Wrong speaker switch, "A" or "B"
speakers when combined with another
speaker output.
pair of 8-ohm speakers will present an
3. Sound source (CD, cassette deck,
impedance to the receiver/amplifier that is
turntable) not turned on, not activated,
approximately 4 ohms. This speaker com-
not hooked up or not selected on
bination can be used with the receiver/
amp/receiver front panel.
amplifier cited in B above. If the receiver/
4. CF120: Blown fuse (see Fuse
amplifier has a specification similar to that
Replacement).
shown in A above, or if your second set of
speakers has an impedance other than No sound from one speaker
8 ohms, you must consult the receiver/1. Balance control turned all the way left
amplifier manufacturer for clarification.or right.
2. Speaker wire has become disconnected.
3.One of the connections between sound
POWER HANDLINGsource and amp/receiver is faulty or has
Thanks to their high efficiency, JBL become disconnected.
CF Series loudspeakers will produce
Both speakers play at low volumes
reasonable volume levels in a room of
but shut off as volume is increased OR
moderate size with very little amplifier
sound turns on and off intermittently
power. However, using a small amplifier to1.A few strands of speaker wire may be
obtain the desired volume listening levels
shorting out. Recheck the connections.
may lead to overdriving the amplifier. This2.More than 1 pair of speakers are
will generate high distortion levels and mayconnected to the amp and the total
cause damage to your loudspeaker. Forimpedance is too low. Recheck the
the best performance, an amplifier should
minimum impedance requirements of
be selected with an output rating that isthe amp.
greater than the maximum power that will
Bass is very weak AND/OR sound
be used. This margin of reserve power will
seems to come from each speaker
ensure that the amplifier will not attempt to
separately, without creating a stable
deliver more power than its design allows.
stereo image between the speakers.
However, the power amplifier's power rat-
1. The polarity (+&�) of one speaker has
ing per channel must not exceed the maxi-
been reversed relative to the other.
mum recommended amplifier power for
Double check connections.
that specific loudspeaker model. Please
2. Speakers are too far away from back
see the specifications section for details.
and side walls or too far apart.
Following these guidelines will provide
distortion-free sound reproduction and Experiment again with the speaker
placement. If you are still encountering
long loudspeaker life.
problems, consult your JBL dealer.
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ACEC
JBL
