Owner's Manual

6
Some words about Power and Ground
The second most common cause of under performing amplifiers is insufficient power
current or a poor power connection. The most common cause of under performing
amplifiers is insufficient ground current or a bad ground connection.
12-volt current: Battery power works only if it travels in a complete circuit from the battery
positive terminal to the battery negative terminal. Main power input, of course, is attached
to the battery positive terminal. Ground current is returned to the battery through the
chassis to the point where the battery is grounded.
The current available for your amplifier to use to produce power will be restricted by the
smallest gauge of wire in the circuit and by the weakest physical connection in the circuit.
Wire Size
It's often surprising how many people will obsess about signal wire but routinely provide
the amplifier with only a fraction of the current it needs to do its job. The most common
wire gauge used in car audio is 10-gauge, and the most common location for amplifiers
is in the trunk.
Wire Sizing Chart
4 ft 7 ft 10 ft 13 ft 16 ft 19 ft 22 ft 28 ft
0-20 amps 14 12 12 10 10 888
20-35 amps 12 10 886664
35-50 amps 10 8866444
50-60 amps 88644442
65-85 amps 66442220
85 -105amps 66422220
105-125 amps 44422000
125-150 amps 22220000
Let's look at a fairly small system. If you use a 50 watt/ch amp (25 amps) for the highs and
a 100 watt/ch amp (40 amps) for the woofers, you need at least a 4-gauge and maybe a
2-Guage wire to provide 65 amps at the trunk. Use the Wire Sizing Chart. Add up the fuse
values on the amplifier(s) then choose the proper size wire based on the distance from
the car battery to the amplifier location. Always use the same gauge wire for the main
ground as you do for the main power. Always make your ground as short as possible and
secure it to a clean solid surface, preferably the vehicle frame.
Length of Run