MB QUART ONX4.80 Car Amplifier User Manual


 
General Instructions
INSTALLATION INSTRUCTIONS
2
General:
Run the wiring so that RCA cables are at least 18“ away from power and speaker cables. Keep RCA cables away from electrical devices in the vehicle
that can cause electrical noise, such as electric fuel pumps, emission control modules and other on-board electronic modules.
Power and ground connections:(See table below)
Use a sufficient gauge power cable and ground cable using the chart below as reference to what size wire you require. Onyx series amplifiers require
at least 4 gauge power wire. In a multi amplifier system, add the total value of the manufacture recommended fusing to get your total system
amperage. Some applications may require multiple runs of power wire to meet the system requirements. In multi amplifier systems it is advisable to
mount a large enough fuse right at the battery, and run one or multiple +12 volt power cables to a fused distribution block near the amplifiers. It is then
a simple matter to connect the +12 volt terminal of each amplifier to the distribution block. During this process, please ensure that the main power fuse
is removed to avoid shorting the electrical system. The main fuse must be within 12” of the vehicles battery.
Ground each amplifier with as short a ground lead as possible directly to the vehicle chassis using at least 4 gauge wire or equivalent to the size of the
amplifiers’ power wire. Use a ground distribution block, if you wish, but it is extremely important to keep the main ground lead from this distribution
block to the chassis as short as possible , not more than 12“. The ground connection integrity to the chassis is very important, and the best way to
achieve a good, solid electrical and mechanical contact is to use a large round crimp lug, crimped and soldered to the ground cable. The next step is to
scrape the paint off the vehicle chassis , slightly larger than the ground lug, at the connection point. Drill a clearance hole in the chassis, the same size
as the lug hole, and use a bolt, spring washer and nut to securely fasten the ground lug. Use petroleum jelly to coat the bolt/lug connection, to prevent
oxidization with time.
TIP: Use the same approach when installing head units, equalizers or any audio equipment for that matter - run short individual grounds from each
piece directly to the vehicle chassis, to minimize ground loops and system noise. All power, ground and speaker connections should be crimped and
soldered for reliability. Make sure that none of the cable insulation can chafe against exposed metal in the vehicle, causing short circuits to the
chassis.
Safe connection sequence:
After all cables are run, connect speaker wires to the speakers and amplifiers, then run and plug in RCA cables. Next, connect all power, ground, and
remote turn on leads. Now connect all +12 volt cables to the amplifier/s and distribution blocks and fuse holders. Finally, connect the main +12 volt
cable to the battery, with the main fuse removed, and we are almost ready to power up the system.
Power up the system:
The following procedure may seem like overkill, but there is nothing more frustrating when turning on a system for the first time, and it does not work
properly immediately.
First, make sure the head unit is off, and turn all level controls to minimum (counterclockwise), including the head unit volume control. Set all equalizers
to 0 dB (no boost), and all crossover frequency controls at approximate frequencies, as recommended by the loudspeaker manufacturer. Set all input
selector and crossover switches as required for the application. Remove all amplifier fuses, and insert the main fuse at the battery. If the fuse does not
blow, you can insert the fuse in one of the amplifiers, and we are ready to turn on the system. Turn the head unit on, insert a CD, or select a radio
station, and increase the head unit volume control. If the system sounds fine, turn off the head unit, and install fuses in the remaining amplifiers, one by
one, till the complete system is powered up and functioning properly.
7-10 ft. 10-13 ft. 13-16 ft.
16-19 ft. 19-22 ft. 22-28 ft.
SYSTEM
AMPERAGE
35-50
50-65
68-85
85-105
105-125
125-150
8
6
4
4
4
2
6
4
4
2
2
0
4
4
2
2
0
0
4
4
2
2
0
0
4
4
2
2
0
0
4
2
0
0
0
0
WIRE LENGTH
WIRE GAUGE