4 Ohm Sub Wiring Diagram – A Complete Guide

When it comes to installing and wiring a subwoofer in your car, it’s essential to understand the basics. This article will provide you with all the information you need to wire a 4 ohm subwoofer properly. We’ll discuss everything from the basic terminology to the detailed wiring diagrams, and common mistakes to avoid. Let’s dive in!

What is a subwoofer?

First things first, what is a subwoofer? A subwoofer is a speaker that is specifically designed to produce low-frequency sound waves or bass. This type of speaker is used to enhance the sound quality of music, movies, and other audio content. Subwoofers come in different sizes, shapes, and designs, but they all function on the same basic principles.

A subwoofer typically consists of a cone-shaped diaphragm, a voice coil, a magnet, and a suspension system. The voice coil is connected to the cone-shaped diaphragm, which moves back and forth to create sound waves. The magnet provides a magnetic field that interacts with the voice coil, causing it to move. And the suspension system helps to keep the diaphragm centered, allowing it to move freely.

What is impedance, and why is it important?

Impedance is the measure of the opposition that a circuit presents to the flow of alternating current (AC). In simpler terms, it’s a measure of how much resistance a speaker has to the flow of electrical current. The unit of impedance is ohms (Ω).

Impedance is an essential consideration when wiring a subwoofer. The impedance rating of a subwoofer affects how much power it can handle and how it should be wired to the amplifier. Most subwoofers have an impedance rating of either 2 ohms, 4 ohms, or 8 ohms, with 4 ohms being the most common.

Wiring a 4 ohm subwoofer – Basic Terminology

Before we get into the details of wiring a 4 ohm subwoofer, let’s take a look at some of the basic terminology that you’ll need to know.

Speaker Level Input

The speaker level input is a way to connect a subwoofer to the amplifier using speaker wires instead of RCA cables. This method is commonly used in older vehicles or in situations where the amplifier doesn’t have RCA inputs.

Line Level Input

The line level input is the most common way to connect a subwoofer to an amplifier. This method uses RCA cables to transmit the audio signal from the head unit to the amplifier.

Impedance

As we mentioned earlier, impedance is the measure of the opposition that a circuit presents to the flow of alternating current (AC). It’s measured in ohms (Ω) and is an essential consideration when wiring a subwoofer.

Wiring a 4 ohm subwoofer – Step by Step Guide

Now that you understand the basic terminology let’s discuss the step-by-step guide on wiring a 4 ohm subwoofer.

Step 1: Determine the amplifier’s minimum impedance rating

Before you start wiring your subwoofer, you need to make sure that your amplifier can handle the impedance of your subwoofer. Most amplifiers have a minimum impedance rating, and if you wire your subwoofer below this rating, you’re likely to damage your amplifier.

To determine the minimum impedance rating of your amplifier, check the owner’s manual or the manufacturer’s website. Most amplifiers have a minimum impedance rating of 2 ohms, 4 ohms, or 8 ohms.

Step 2: Check the subwoofer’s impedance rating

The next step is to check the impedance rating of your subwoofer. The impedance rating is usually printed on the back of the subwoofer or in the owner’s manual. Most subwoofers have an impedance rating of 2 ohms, 4 ohms, or 8 ohms.

Step 3: Decide on series or parallel wiring

Once you know the impedance rating of your amplifier and your subwoofer, you need to decide on the wiring configuration. You can wire your subwoofer in series or parallel.

Series Wiring

In series wiring, you connect the positive terminal of one subwoofer to the negative terminal of the other subwoofer. Then, you connect the remaining positive and negative terminals to the amplifier. The impedance of the subwoofers is added together, resulting in a higher overall impedance.

Parallel Wiring

In parallel wiring, you connect the positive terminals of both subwoofers to the positive terminal of the amplifier, and the negative terminals of both subwoofers to the negative terminal of the amplifier. The impedance of the subwoofers is divided by two, resulting in a lower overall impedance.

Step 4: Follow the wiring diagram

Once you’ve decided on the wiring configuration, it’s time to follow the wiring diagram. The wiring diagram will show you how to connect the subwoofer to the amplifier using either series or parallel wiring.

Common Mistakes to Avoid

Wiring a subwoofer can be complicated, and it’s easy to make mistakes. Here are some common mistakes to avoid:

Mistake 1: Wiring the subwoofer at the wrong impedance

Wiring your subwoofer at the wrong impedance can damage your amplifier or subwoofer. Make sure you check the impedance rating of both your amplifier and your subwoofer and wire them accordingly.

Mistake 2: Overloading your amplifier

Overloading your amplifier can cause it to overheat or shut down. Make sure you know the power rating of your amplifier and don’t exceed it when wiring your subwoofer.

Mistake 3: Forgetting to ground your amplifier

Grounding your amplifier is essential to prevent electrical interference and noise. Make sure you ground your amplifier correctly to avoid any issues.

FAQs

Q: Can I wire a 4 ohm subwoofer to a 2 ohm amplifier?

A: No, wiring a 4 ohm subwoofer to a 2 ohm amplifier can damage your amplifier. Make sure you wire your subwoofer at the right impedance.

Q: Can I wire two 4 ohm subwoofers to a 4 ohm amplifier?

A: Yes, you can wire two 4 ohm subwoofers to a 4 ohm amplifier using series wiring. This will result in an overall impedance of 8 ohms.

Q: What happens if I wire my subwoofer at a lower impedance than my amplifier?

A: Wiring your subwoofer at a lower impedance than your amplifier can cause it to overheat or shut down. Make sure you wire your subwoofer at the right impedance to avoid any issues.

Conclusion

Wiring a 4 ohm subwoofer can be challenging, but with the right information, you can do it correctly. Remember to check the impedance rating of your amplifier and your subwoofer and wire them accordingly. Avoid common mistakes such as overloading your amplifier or forgetting to ground it. If you follow the step-by-step guide and the tips we’ve provided in this article, you’ll be enjoying high-quality bass in no time!