What Impedance Should I Wire My Subwoofer?

When you are all set and ready to add a subwoofer with killer bass to your vehicle, there are plenty of options to choose from. After getting past all the basic questions about size and number of subwoofers you want in your car, the hardest part is yet to come. You could have all the right components in all the right places, but it’s all in vain if you get the specifications wrong. This confusion about amps, watts, and ohms has been around ever since the inception of the first sound system.

Section Description
1. How Impedance Works Defined as the resisting property of the voice coil and is measured in ohms. The lower the impedance the easier it is for the amplifier to supply power to the subwoofer.
2. Wiring Options For Subwoofer Two options include parallel and series wiring. When you connect (+) to (+) terminals and (-) to (-) terminals this is known as parallel wiring, reducing the ohm output. When the amp sends an audio signal that travels through all the (+) outputs and continues through the (-) outputs until the cycle is complete; this is series wiring and increases ohms.
3. Examples Of Arrangements Depending on how many coils your subwoofer has will affect the type of arrangement you will want to go with.

Power and impedance are set up and entangled through a series of math formulas in such a way that they are intimately linked. If one of them undergoes even the slightest change in value, so does the other. One of the most common questions that we usually get revolves around what impedance should I wire my subwoofer? If you’ve been asking yourself this question, here’s all you need to know about impedance and wiring.

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1How Impedance Works

At the very heart of every subwoofer and speaker is a voice coil. This is the components responsible for putting out electrical resistance and performing all the work in your sub. The resisting property of a voice coil is what is referred to as impedance and is measured in ohms. The lower the sub’s impedance, the easier it is for an amplifier to supply power to it. However, problems tend to come in since most amplifiers are not designed to handle such low levels of resistance. This leads to the amplifier trying to put out more power than it was designed to handle. This leads to overheating and finally, total shutdown of your amplifier. As such, the specifications of the amplifier needs to be considered before wiring your subwoofers to a particular impedance.

2Wiring Options for Subwoofer

For those of you that were not aware of this fact; total impedance of your subwoofers will depend on how the subwoofer and voice coils are wired. The number of subs and the arrangement should also be considered before wiring your subs to any particular impedance. Two types of wiring include:

Parallel Wiring

This simply means that the connection ends of each device are connected to the same thing; positive to positive terminals, and negative to negative terminals. If your subwoofers or speaker voice coils are wired in parallel, then the impedance value should be divided by the number of units you have connected. For example, installing four 4 Ohm subwoofers with parallel wiring will you give you a total impedance of 1 Ohm. Ultimately this has the opposite effect of series wiring because the impedance is lowered, in addition the more speakers wired the lower the impedance. This is due to the fact that the amplifier output is increased, because more power is required for the additional units.

parallel wiring two subs and impedance

Series Wiring

Series wiring simply means that all your subwoofers, speakers and voice coils are wired together one after another. In this case, the positive terminals are in contact with subsequent negative terminals and so on and so forth. To find the impedance of subwoofers wired together in a series, all you have to do is add their impedance together to find the total. For example, two 4 ohm subwoofers wired in a series will have a total impedance of 8 ohms. You add the impedance of all the units together because you need to take the combined resistance of the units to determine the total impedance.

series wiring 2 subs with impedance

With this in mind, you should now select an amplifier that can handle the impedance produced as a result of wiring. Here are some specific examples that should help you get the right idea on wiring subwoofer impedance.

3Examples of Arrangements

Since every car owner installs their sound system differently, we will look at all the different arrangements, types of subwoofers as well as how to wire the impedance of each get up to get the most out of your system:

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4 Ohm Single Voice Coil Subwoofer

A single subwoofer is very easy to hook up and offers simplicity and is very compact. If this is your preferred arrangement, the ideal power source to use is a 2 channel amplifier. This is perfect for most amplifiers which can comfortably handle 4 ohms. Avoid using mono amps here since they work best at a lower impedance.

4 Ohm Dual Voice Coil Subwoofer

Having two different coils gives you more wiring options to work with. In this case, use a mono amp since they can provide adequate power at lower impedances. Wire your subwoofers in parallel to present them with a 2 Ohm impedance that a mono amp can comfortably handle.

Born in a subwoofer box, music has always been my passion. At the proud age of 9 I began driving. The two eventually met and led to my career at Sonic Electronix.

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