A dual subwoofer setup is an amazing solution to bring more bass to your audio system and to make the low frequencies sound larger than life. However, your amplifier might not meet the impedance of your subs. What to do in that case?
It is completely possible to wire a pair of subs in a way that will decrease their impedance. This will be extremely helpful if you have, for example, an amplifier with 2 ohms of impedance that you want to connect your subwoofers to.
In this article, we will guide you through the step-by-step on how to wire two dual 4-ohm subs down to 2 ohms, list the tools you will need, and give you a few tips and tricks to nail the job. Let’s get started!
How to Wire 2 Dual 4 Ohm Subs Down to 2 Ohms? [Best Way]
The best way to wire 2 dual 4-ohm subs down to 2 ohms is to connect them in parallel by wiring the positive and negative terminals of each sub together. Doing this allows you to wire both subs to your amplifier as you normally would.
There are two basic ways to wire your subs: in parallel and in series. We chose parallel wiring as our preferred method for this particular case because it will work with most speakers and amplifiers, and the amp will maintain its power output.
However, in some cases wiring your system in series will be preferred, as we will explain below in the article.
Tools and Materials
Before we present you our step-by-step guide, let’s look at some of the tools and materials you will need to complete the job.
Speaker Wires
Speaker wires are specially designed for car audio systems, but there is a particular specification you must take into account when shopping for them: the wire gauge.
The wire gauge of a speaker wire will determine how much power output it can handle. To find the best number for your particular case, you must consider the RMS power of both of your subwoofers and your amplifier, plus, the wire run length.
Here is a quick chart to help you decide which wire gauge to use:
| Subwoofer RMS Power | Wire Run Length | Wire Gauge |
| Up to 500 Watts | Up to 4 Feet | 12-Gauge Wire |
| Up to 1000 Watts | Up to 7 Feet | 10-Gauge Wire |
| Up to 1500 Watts | Up to 10 Feet | 8-Gauge Wire |
| Up to 2500 Watts | Up to 15 Feet | 6-Gauge Wire |
| Up to 4000 Watts | Up to 20 Feet | 4-Gauge Wire |
Remember that the process of wiring two dual 4-ohm subs together will change the power output of your system. Take that into account when selecting your wire gauge.
As for price, you can get 50ft of cable (that will probably last you a lifetime) for as low as $12 on Amazon, regardless of the gauge of the wire, so it’s a pretty affordable component.
Ring Terminals (Optional)
Ring terminals are small metal connectors featuring a shrinking sleeve that can be attached to a wire. They are not exactly necessary, but they are a great option if you don’t want to deal with soldering your connections.
With a ring terminal, you can simply screw in a wire to your speaker and amplifier’s terminals, securing it in place and making your job much easier.
You can find these metal connectors in any electronics/general store for a few cents, or, you can buy them in hundreds on Amazon. We definitely recommend you buy a few.
Speaker Wiring Kit (Optional)
Instead of buying each material separately, you can opt to buy a speaker wiring kit that will feature a few meters of wire, ring terminals, and all of the components you will need to connect your audio system together.
However, this option is best if you’re building a complete audio system from scratch. If you already have one installed in your car and just need to wire your two subwoofers, buying the wire and the ring terminals separately makes more sense.
How to Wire 2 Dual 4 Ohm Subs Down to 2 Ohms?
Below, we will explain step-by-step how to wire 2 dual 4-ohm subwoofers down to 2 ohms using two different methods.
Methods to Wire Dual 4 Ohm Subs To 2 Ohms [2 Methods]
There are essentially two methods to wire dual 4-ohm subs down to 2 ohms: using parallel or series wiring. The best one will depend on your particular setup and your equipment specifications. We will explain everything in detail below.
Step-By-Step Instructions for Each Method
1. Parallel Wiring
Parallel wiring involves connecting the positive terminals of both subwoofers to the amplifier’s positive terminal and the negative terminals of both subwoofers to the amplifier’s negative terminal. Parallel wiring results in a lower impedance load (typically 2 or 4 ohms), allowing the amplifier to deliver more power to the subwoofers.
This is a great method if you have a pair of subs that require a lot of power to function properly since it will prevent any losses in the low frequencies due to voltage restrictions. Here is the step-by-step:
- Turn off your amplifier completely and remove it from its power source.
- Wire the positive terminals of both subwoofers together.
- Wire the negative terminals of both subwoofers together.
- Test the circuit with a multimeter and make sure it reads 2 ohms.
- Wire the positive terminal of the remaining voice coil on your first subwoofer to the positive terminal of your amplifier.
- Wire the negative terminal of the remaining voice coil on your second subwoofer to the negative terminal of your amplifier.
- Proceed to turn on your system and test its audio quality.
2. Series Wiring
Series wiring connects the positive terminal of one voice coil of the first subwoofer to the amplifier’s positive terminal and the negative terminal of the other voice coil of the second subwoofer to the amplifier’s negative terminal.
The remaining positive and negative terminals of the subwoofers are wired together. Series wiring will result in a higher impedance load and reduce the amount of power the amplifier can deliver to the subwoofers.
Here’s how to wire your subwoofers in series:
- Disconnect your amplifier from the power source and turn it off completely.
- Wire the positive terminal of the first voice coil of subwoofer 1 to the positive terminal of the second voice coil of subwoofer 2.
- Wire the negative terminal of the second voice coil of your subwoofer 1 to the negative terminal of the first voice coil of your subwoofer 2.
- Test the circuit with a multimeter and make sure it reads 2 ohms.
- Wire the positive terminal of the second voice coil of your subwoofer 2 to your amplifier’s positive terminal.
- Wire the negative terminal of the first voice coil of your subwoofer 2 to your amplifier’s negative terminal.
- Proceed to turn on your system and test its audio quality.
Disclaimer: Regardless of which method you choose, we recommend you test your circuit with a multimeter before turning it on, as it will help you avoid any damage to your devices.
Here’s how to do so:
- Disconnect both subwoofers from your amplifier.
- Configure your multimeter to display the resistance (ohms).
- Touch the multimeter probes to the positive and negative terminals of the wires that go from your subwoofers to your amplifier.
- In the context of this article, the multimeter should read 2 ohms. If that’s the case, your wiring is correct and you can connect your speakers to your amplifier.
If the resistance is 0.5 ohms lower or higher than your desired 2 ohms, then there is most likely a problem with your equipment or wiring.
In that case, you can test each voice coil separately by doing the same process: touch the probes of your multimeter to your voice coil’s positive and negative terminals.
If the multimeter reads 4 ohms, the problem is most likely related to your wiring. If the reading is way out of this range, you should contact the manufacturer of your subwoofers to discuss a solution for the problem.
Factors to Consider When Wiring Dual 4-Ohm Subs
Check if your Amplifier is Compatible with a 2-Ohm Load
Not all amplifiers are designed to work with a 2-ohm load. Failing to match the impedance of the speakers to the amp could result in overheating issues and even serious accidents. For that reason, always check the owner’s manual and the specifications of all the equipment present in your audio system.
Consider the Power Output of your System
Wiring two dual 4-ohm subs down to 2 ohms will allow more electrical current to flow through your speakers and therefore increase your amplifier’s power output due to the lower resulting impedance of the circuit.
That said, check the maximum power output your subwoofers can receive to ensure it is within what your amplifier can deliver.
Follow the Safety Guidelines
It doesn’t hurt to say that working with electrical components can be dangerous. Always turn your system off completely before wiring your speakers. We recommend waiting at least 30 minutes after turning your amplifier off to start working on it.
Another thing you can do to make your job safer is to turn off your car battery. Simply find it under the hood and unplug the negative terminal.
Use the Correct Equipment and Materials
Using the right wire gauge and connectors on your circuit will ensure your system has the best possible audio quality and prevent issues from happening. Please refer to our chart under “Tools and Materials” to learn which wire gauge to use for your particular case.
Choose the Best Method for your Particular Case
As we discussed, you can wire your subwoofers in parallel or in series. We recommend parallel wiring for most cases since you won’t have an effect on your power output as parallel wiring does.
Maintaining the power output of your system is important to guarantee the best audio quality on your low frequencies. Series wiring is best if you have a higher-impedance amplifier.
Check our article on ‘Best Surround Sound Amplifiers For 5.1 & 7.1 Systems‘.
Conclusion
That concludes our article on how to wire two dual 4-ohm subs down to 2 ohms. If you have an amplifier with an impedance load of 2 ohms, the process will help you achieve the best sound quality with your audio system, especially on low frequencies.
Remember to follow safety guidelines and choose the best method for your own setup based on your subwoofer and amplifier’s specifications. The owner’s manual should always be consulted before any wiring process.
It is also worth remembering that you should take not only the impedance but also the power output of your circuit into account as well. Make sure to choose the right wire gauge based on the RMS power of your devices and the wire length run.