Don't cheap out on your power wire!

0 Gauge Wire going into a JP23 Amplifier.

You need a big thick power cable (with a fuse near the battery) to get DC power from your battery to your amplifier. But wire, especially high-quality copper wire, can be very expensive.

Here are some examples:

Kicker Dual Amp Kit

KnuKonceptz Dual Amp Kit

4 Gauge Power Wire for a JL Audio Amplifier

To help you figure out what you need, without wasting your hard earned cash, just plug some info into this calculator and you will be all set! The calculator is designed to let you pick the wire size and it will tell you how much voltage drop you will get due to the resistance of the power wire. That voltage drop will either be green (good to go) or red (you need a bigger power wire)

A few things first

There are two types of wire Oxygen Free Copper and Copper Clad Aluminum (CCA). CCA is cheaper, but has 50% more internal resistance and is significantly more prone to corrosion. Thus CCA is never recommended. But, you can spend your money any way you like. So both are included in the calculator.
Some amplifier manufacturers lie about their power ratings or list bogus "peak" or "max" ratings. Use only RMS wattage. Watch a few amp dyno videos to figure out which brands lie about power ratings and which brands provide reliable numbers. If you are running multiple amplifiers then input your total system power in watts RMS.
Cars run on 12v DC, but they don't. Your voltage in your car, assuming it has not been modified, will be between 12 with the engine off and 14.4 with the engine running. 13.8 is a good middle ground, but you can input a wide range into the voltage field. Be realistic.
Amplifier efficiency varies widely. Class AB amps are less efficient than class D. I usually assume 60% for class AB and and 80% for class D. If you are running cheap amplifiers pick a lower number, quality amplifiers (like this one) will be much more efficient. But no amp is 100% efficient.
For the wire length this is your main power wire that runs from your battery to your amplifier. If you have multiple amplifiers then you will need a fused distribution block when you split your wire down into smaller wires for individual amplifiers. For this calculator just assume that you are running a power wire directly from the battery to the amplifier.
Choose your wire size, the ones listed are the ones commonly available from car audio retailers.
Hit calculate and you will get your voltage drop, green means go and red means you need a bigger wire.

DC Power Wire Voltage Drop Calculator

Wire Type:

Amplifier RMS Power (Watts):

System Voltage (Volts):

Amplifier Efficiency (%): (Enter 50-90)

Wire Length (Feet):

Wire Size:

Results:

Enter all values and click "Calculate" to see the voltage drop.

Suggested Wire

Not all amplifer kits are made the same, some do not include RCA wires and distribution blocks. If you need those here are some recomendations.

To learn more about power wire check out this helpful video

What is a dual voice coil subwoofer and how do you wire it?

All you really need to know is that a dual voice coil has two sets of terminals, this gives you added flexibility when connecting a subwoofer to an amplifier. Speaker resistance is much more complex, more on that below. But for now the goal is to match the nominal impedance of your subwoofer (or subwoofers) to your amplifier. Here is a schematic to show the difference between single and dual voice coil subwoofers.

Here is a picture of a pair of dual voice coil subwoofers, the terminal pairs are circled in red. There are two pairs on each subwoofer. In this case the voice coils are wired in series. For more on this scroll to the bottom of the page for some sample wire diagrams.

Here are some schematics showing the two ways that you can wire up a dual voice coil subwoofer.

Here is an example of a single voice coil subwoofer. It has just one set of terminals.

Here are some schematics demonstrating series vs parallel for a single voice coil subwoofer.

Subwoofer Ohms (Series-Parallel) Calculator

With the above information you should know enough to use this calculator, additional wire diagrams are included below. One caveat, this calculator will not let you mix impedances or numbers of voice coils. It assumes that you are working with matching subwoofers.

Subwoofer Resistance Calculator

Select Voice Coil Resistance (Ohms):

Select Number of Voice Coils:

Select Coil Configuration:

Number of Subwoofers:

Select Subwoofer Configuration:

Now I am going to break your brain!

In this picture I am measuring a 4 Ohm voice coil and it is not 4 ohms!

That is because subwoofer impedance is actually a lot more complex. I explain some of that in this video:

As you can imagine there is a near infinite number of possible wire configurations. Here are some examples to help you get started wiring up your own system.