JBL MS 8 Service Manual ▷ View online
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POWER
IMPORTANT: Perform the power connections in the following order.
1. Gnd: Connect this terminal to a paint-free location on the vehicle chassis.
IMPORTANT: Use at least 12-gauge wire for this connection.
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CONNeCTiONs
REMOVE
FOR
SOFTWARE
UPDATE
25A
fuse
Mic
connection
Line input
connections
Hi Level input
Remote out
connection
Speaker output
connections
Line output
connections
Aux input
connections
Display
connection
Power
LED
Reset
button
Update
connection
+12V
connection
Remote in
connection
GND
connection
Chassis
ground
(unpainted)
5
CONNECTIONS
MS-8
4
CONNeCTiONs
To turn-on
terminals of
all system
amplifiers
+
-
1 x 25A
25A fuse within
18" of battery
terminal
Cable from MS-8
+12V terminal
Use a grommet
through the
firewall
3.
Rem Out: Connect this terminal to the remote turn-on terminals of all amplifiers in the system. The
output is +12V DC, 1A.
IMPORTANT: The MS-8 MUST control the turn-on signal of all the other amplifiers
that follow the MS-8 in the signal path.
If your system includes a factory-installed outboard amplifier, the turn-on signal
may be available at the amplifier. If your factory amplifier has a turn-on wire, cut it
and connect the head-unit side of the wire to the MS-8’s Rem In terminal and the
amplifier side of the wire to the MS-8’s Rem Out terminal.
This arrangement will allow the factory stereo to turn the MS-8 on whenever the
stereo is turned on and will allow the MS-8 to turn the factory amplifier on and off.
It will also help to eliminate audible clicks and pops when the system turns on and
off.
2. +12V: Connect this terminal to the vehicle battery’s positive (+) terminal. Insert a 25A fuse in series on
the +12V wire no further than 18 inches (46cm) from the battery terminal.
IMPORTANT: Use at least 12-gauge wire for this connection.
6
CONNECTIONS
MS-8
5
eCTiONs
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lis
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Rem In: Connect this terminal to the remote turn-on output of the system’s source unit, if the
source unit has a remote turn-on output. Alternately, you can connect this terminal to the vehicle’s
accessory (ACC) power circuit. Any voltage over +4V DC at this terminal will trigger the MS-8 to
turn on.
NOTE: See Step 3 for more details about connecting the Rem In terminal to a factory-installed
stereo system.
AUDIO INPUTS
Many factory-installed systems include on-board equalization and crossovers that make simple
connection of aftermarket products difficult. The MS-8 includes the signal-summing circuitry, signal-
conditioning EQ and time-correction processing that are necessary to reconstruct a flat, full-range,
two-channel signal when you use the MS-8 with factory-installed equipment.
Aftermarket head units with line outputs provide a flat, full-range, two-channel signal on their front line
outputs, so you need to connect only those channels to the MS-8.
To head unit
remote turn-on
or vehicle
ACC terminal
7
CONNECTIONS
MS-8
6
CONNeCTiONs
Aftermarket head unit
MS-8 main unit
Rear
line out
Front
line out
RCA
audio cables
Subwoofer
line out
DO NOT USE
Line inputs
1 and 2
Connecting an aftermarket head unit
If you’re using the MS-8 with an aftermarket head unit that has RCA-type outputs, connect the head unit’s
front left and front right outputs to the MS-8’s line inputs 1 and 2 only. Do NOT connect any other head-unit
output signals to the MS-8’s line inputs 3 – 8. During the calibration/setup process, the MS-8 will “normalize”
the input signals and derive as many output signals as your speaker system requires.
IMPORTANT: Do not connect the head unit directly to any amplifiers, including a subwoofer amplifier. The
MS-8’s signal processing takes nearly 8ms, so any signals connected directly to a head-unit will be ahead
of the signals leaving the MS-8 by about 8ms. This difference will cause them to be out of sync with the
signals that pass through the MS-8.
The MS-8 must generate all the signals that are sent to all of the
system’s speakers!
8
CONNECTIONS
MS-8
7
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