Setting Crossover; Setting Input Sensitivity; Troubleshooting; Controls And Setup - JBL MA6004 Owner's Manual

CONTROLS AND SETUP

SETTING THE
CROSSOVER(S)
Determine your system plans and set
the crossover mode switch accordingly.
If your system design does not include
a subwoofer with the MA6004, set the
crossover mode to FLAT; if you are using
speakers that are 5 inches in diameter or
larger, skip to "Setting Input Sensitivity. "
Initially set the crossover frequency
control midway. While listening to music,
adjust the crossover for the least
perceived distortion from the speakers,
allowing them to reproduce as much
bass as possible.
For systems using a separate subwoofer,
set the crossover mode to HP (high pass)
for your full-range speakers. Adjust the
crossover frequency to limit bass and
provide increased system volume with
less distortion.
For subwoofers, choose the highest
frequency that removes vocal information
from the sound of the subwoofer.
If using the MA6004 or MA6002 to drive a
subwoofer(s), set the crossover mode to
LP (low pass).
SETTING INPUT
SENSITIVITY
1. Initially turn the INPUT LEVEL control(s)
to minimum (counter clockwise).
2. Reconnect the (–) negative lead to the
boat's battery. Apply power to the audio
system and play a dynamic music track.
3. On the source unit, increase the volume
control to 3/4 volume. Slowly increase
the INPUT LEVEL control(s) toward
"three o'clock" until you hear slight
distortion in the music. Then reduce
the INPUT LEVEL slightly until distortion
is no longer heard.
NOTE: After the source unit is on,
blue LEDs (on the top panel) will light,
indicating the amplifier is on. If not,
check the wiring, especially the remote
connection from the source unit. Also
refer to the "Troubleshooting" guide.

TROUBLESHOOTING

SYMPTOM LIKELY CAUSE
No audio No voltage at BATT+
(POWER LEDs or REM terminals,
are off) or bad or no ground
connection
No audio Amplifier is
(POWER overheated
LEDs are on)
Voltage more than 16V
or less than 8.5V on
BATT+ connection
No audio Voltage less than 9V on
(POWER BATT+ connection
LEDs flash)
DC voltage on
amplifier output
Distorted audio Input sensitivity is
not set properly, or
amplifier or source
unit is defective
Distorted audio Short circuit in
and POWER speaker or wire
LEDs flash
Music lacks Speakers are not
"punch" connected properly
SOLUTION
Check voltages at
amplifier terminals
with VOM
Make sure amplifier
cooling is not blocked
at mounting location;
verify speaker-system
impedance is within
specified limits
Check boat's battery
charging system
Check boat's
charging system
Amplifier may need
service; see enclosed
warranty card for
service information
Check INPUT
LEVEL setting; or
check speaker wires
for shorts or grounds
Remove speaker leads
one at a time to locate
shorted speaker or
wire, then repair
Check speaker
connections for
proper polarity