Wire size – Zapco AG Reference-series User Manual
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Wire Size
Most people understand the importance of a clean signal source for
good sound reproduction. But, what about your 12 volt power source? It’s
often surprising how many people (even professional car audio people) will
obsess about signal wire but routinely provide the amplifier only a fraction of
the current it needs to do its job. The most common wire gauge used in car
audio is 10-gauge. The most common location for amplifiers is in the trunk.
Take a look at the chart below. If you want to have any respectable
amount of power for your amp, you need an 8-gauge wire to the trunk as a
bare minimum. If you want enough power to drive woofers, you’re going to
need at least a 4-gauge wire to the rear.
Length of Run
0-
4 -
7 -
10 - 13 - 16 -
19 -
22 -
Current Demand 4 Ft 7 Ft 10 Ft 13 Ft 16 Ft 19 Ft 22 Ft 28 Ft
0 - 20 amps
14
12
12
10
10
8
8
8
20 - 35 amps
12
10
8
8
6
6
6
4
35 - 50 amps
10
8
8
6
6
4
4
4
50 - 60 amps
8
8
6
4
4
4
4
2
65 - 85 amps
6
6
4
4
2
2
2
0
85 - 105 amps
6
6
4
2
2
2
2
0
105 - 125 amps
4
4
4
2
2
0
0
0
125 - 150 amps
2
2
2
2
0
0
0
0
Lets look at a fairly small system. If you use a Reference 200.2 (25
amps) for the highs and a Reference 350.2 (40 amps) for the woofers, you
need at least a 4-gauge wire to provide 65 amps at the trunk. Anything less
and your car won’t go boom. It’ll just go Blap!
It takes lots of current to make lots of power!
And remember! An electrical circuit is just that…a circuit. For current
to travel, you must complete the circuit from the positive terminal to the
negative terminal. Whatever you use for power (B+) you must also use for
Ground (B-). 4-gauge power wire…4-gauge ground wire!
So! Use this supplied 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. Very important, 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 attach to a clean solid surface.