There are several ways to wire subwoofers and speakers to an amplifier. The most ideal way is to wire your subwoofer to match the impedance and RMS power output that will give you the best performance from your system. In this post, I will explain subwoofer characteristics such as voice con configuration, and how to properly wire your subwoofers or speakers. I will also provide some basic wiring diagrams to help get you pointed in the right direction when you finally start to wire up your subwoofer(s).
Before we get into the wiring aspect, let’s take a look at the two voice coil (VC) configurations that most subwoofers have. This will help you better understand what type of subwoofer configuration you may have and will ultimately help you when choosing which wiring configuration is most ideal for you.
Voice Coil Configuration
Single Voice Coil (SVC)
The single voice coil (SVC) subwoofer is the most simplistic. This means that the subwoofer has one voice coil. You can tell the subwoofer is a single voice coil because it will only have one set of speaker terminals. One labeled positive (+) and one labeled negative (-). Sometimes, the terminals will also be color-coded. Red for positive and Black for negative.
Dual Voice Coil (DVC)
The dual voice coil (DVC) subwoofer is the most common in-car audio. A dual voice coil subwoofer has two voice coils. You can identify a DVC subwoofer by the two sets of speaker terminals. The speaker terminal is labeled just as the SVC subwoofer. So why a DVC? Well, simply put, a single DVC subwoofer will give you more wiring options over a single SVC subwoofer. This means a single DVC subwoofer can actually be wired to create two different impedances, whereas a single SVC subwoofer can only remain at its labeled impedance.
NOTE: There are also subwoofers produced that contain more than two voice coils. These are the less common quad voice coils subwoofers. In this post, we will not be discussing this type of voice coil configuration because it can make things a little too complicated for a car audio newcomer.
Other Related Terms
Impedance is the amount of electrical “load,” or resistance a subwoofer puts on an amplifier’s outputs. Impedance is measured in what is called Ohms. Subwoofer voice coils typically will come in 2-ohm, 4-ohm, and 8-ohm configurations. The subwoofer’s impedance is usually listed on the subwoofer itself or printed on the packaging or user’s manual. If you are unsure of the impedance of your voice coil(s), you can measure their impedance by using a multimeter set to the Ohms setting.
NOTE: If you are checking the subwoofer’s impedance with a multimeter, please be aware that the reading may not always be spot on. For example, a 2-ohm voice coil may read 2.3 ohms on the meter. This is within range of what is considered to be a 2-ohm voice coil.
Amplifier Power Output (RMS) Ratings
An amplifier’s output rating is measured in watts. More specifically, watts RMS. The RMS (Root Mean Square) rating is the power the amplifier can produce on a continuous basis. It is also the rating of power your subwoofer or speakers can handle continuously without being damaged, considering your amplifier has been set up properly, but that’s another topic. An amplifier’s RMS power output can change depending on the load it “sees” from the subwoofer. Many amplifiers will have power output ratings listed for 4-ohm, 2-ohm, and some amplifiers will list ratings for ohm loads of 1-ohm and below. Refer to your amplifier’s manual for its specific RMS ratings and what impedance those ratings are listed for.
Okay, now that we got that out of the way, let’s finally look at the two wiring configurations for subwoofers and speakers.
When a subwoofer, or subwoofers, are wired in series, you are in essence, creating one single circuit for electricity to flow, raising the resistance on the amplifier’s output. This, in turn, yields less power from the amplifier. In order to wire in series, you are connecting positive to negative. Connecting a subwoofer, or subwoofers, in the series configuration, you are creating a higher impedance or load for the amplifier. For example, if you have two 4-ohm SVC subwoofers and you wire them in series, your final impedance would be 8 ohms.
When wiring in the parallel configuration, you are creating two paths for electricity to flow through the subwoofer(s). This “dual circuit” lowers the resistance in the amplifier’s output, allowing it to produce more RMS power. In order to wire in parallel, you are basically connecting the positive to positive and negative to negative. Connecting a subwoofer, or subwoofers, in parallel, lower the impedance or load on the amplifier. For example, if you have two 4-ohm SVC subwoofers and you wire them in parallel, your final impedance would be 2 ohms.
In some instances, you need to wire your DVC subwoofers in what is known as series/parallel. This configuration, by its name, is a combination of the two different wiring configurations. This type of wiring configuration can get a little confusing, but this basic diagram (shown to the right) will help you better visualize it.
I know that speaker wiring can be quite confusing at times, but with the basic knowledge provided in this post, it should be a little easier to grasp. I hope this post has given you some basic knowledge to get you pointed in the right wiring direction.