We are reader supported. When you purchase products through links on this page, we may earn an affiliate commission. Learn More.

How To Connect A Subwoofer To A Car Stereo Without An Amp

Installing a subwoofer on your stereo can increase the audio bass, minimize distortion, and increase volume for the best hearing experience. An amplifier supplies the necessary power for a subwoofer. But, can a subwoofer work without an amp? If yes, how to connect a subwoofer to a car stereo without an amp?

Yes, active subwoofers can be directly connected to your stereo without any extra amplifier. You can connect both active and passive subwoofers with your automobile battery. Or, the device can be powered by attaching it to your car stereo's existing wiring.

Another way of connecting a subwoofer is to use line output converters. However, without an amplifier, the sound quality won't be up to the mark. Let's dive deeper and find out more about installing subwoofers without an amplifier.

First things first, you need to understand why you need a subwoofer and amplifier and how they work. As you might know, low-frequency sounds are also popularly known as bass.

If you want to enjoy deep vocals and music with clarity, your audio system must produce deep thumping bass. Unfortunately, your basic car stereo can't produce good bass and that's where you need a subwoofer.

understanding car amplifier and subwoofer

This device reproduces frequencies as low as 20 Hz to 200 Hz. You can compare it to the human hearing range (20 Hz to 20,000 Hz) to understand how low the frequency is.

This low-frequency sound ensures that you hear authentic and dynamic audio without any distortion.

A subwoofer uses magnets and coils to achieve immersive and deep bass. And to power those magnets, you'll need an amplifier.

As the name suggests, amplifiers use the weak signal coming from your stereo and amplify it so that your subwoofer can use stronger signals. Also, it enhances the stereo power and makes it useful for the subwoofer.

Without an amplifier, your subwoofer might not work at all. Or, it will produce distorted sounds with lower volume.

Connecting Subwoofer without An Amp - Is It Possible?

Yes, you can connect a subwoofer to your car stereo without an amplifier. However, this will decrease the sound quality and increase audio distortion. Sometimes, the subwoofer might not work at all as it won't get the necessary power to work.

Here, the best solution is to purchase an active subwoofer featuring a built-in amplifier. This type of subwoofer doesn't require any external amplifier to improve the sound quality, thanks to its integrated amplifier.

Another type of subwoofer is the passive sub that doesn't have any subwoofer integrated into the device. So, you should get an additional amplifier to provide the necessary power.

However, if the subwoofer is smaller and requires very low power to function, you can directly connect it to your vehicle battery or stereo. In this case, you can use a passive subwoofer without an external amplifier.

Some Basics of Connecting Subwoofer To Car Stereo Without Amp

Lucky for you, we have not only one, but multiple ways of connecting a subwoofer without an amp. You can choose any of the methods depending on the type of your subwoofer. Before anything else, let's start with some basics that will ease up your work.

Basic One: Active, Passive, Or Vehicle Specific - Which Subwoofer to Choose?

Typically, subwoofers fall into 3 main categories: active, passive, and vehicle specific. You must decide on which one you want before you proceed with the installation process. Of course, active subwoofers are the best option for installation without amplifiers.

If you have a smaller car or special requirements, you can go for custom-made vehicle-specific subwoofers with integrated amplifiers. Finally, you can choose the right passive subwoofer based on your vehicle's battery power.

Basic Two: Decide Where the Subwoofer Fits

To match diverse needs, subwoofers come in many different sizes and power requirements. Not all subwoofers will fit your vehicle. So, you must choose the right subwoofer size that can be placed inside your car.

While choosing a mounting spot, make sure it's not too far from your vehicle's head unit. Also, there shouldn't be any obstacles that might block the signal. We recommend placing the subwoofer under your car seat for the best results.

Some also place the device behind the car's spare wheel or inside the trunk. Whichever spot you choose, you should be able to connect the subwoofer wires to the head unit or speakers.

Basic Three: Is There Enough Power for the Sub? - Check Out First

Some subwoofers require a generous amount of power for their cones and magnets to work. If you're connecting the sub directly to the car stereo or battery, you must not exceed their maximum capacity.

Otherwise, the subwoofer won't function at all. So, check out how much power your car can deliver without an amp before you purchase a sub. You can also install an adapter to ensure there's sufficient power for your subwoofer.

Basic Four: Keep the Required Tools Close

This will help you a ton during the installation process. No matter which strategy you choose, you'll need some common tools including a tester, screwdriver, wire stripper, wiring kit, additional wires, etc.

Collect all these tools and proceed to the next phase. Let’s learn the installation process of a subwoofer without an amp-

The Easiest Way - Use Your Car Stereo Wires to Attach the Subwoofer

This super easy process will work for all types of subwoofers.

All you need to do is find the right wires and connect them to the subwoofer. Here's how you can proceed-

If you don't have any basic knowledge of your car's stereo wiring, go through your owner's manual first. Disconnect the ground power cable of your car battery to avoid getting unwanted shocks. Now, check your stereo speakers for a spare power wire.

Connecting Subwoofer to Car Stereo Without An Amp

The stereo's power wire is thick and red or yellow in color. Don't worry if you can't find an additional power wire. You can drive one directly from the head unit instead.

Once you have a connection wire in hand, take a wire stripper and strip off about one or half inches from the wire cover. To confirm that it's a stereo power wire, check if the open end of this wire is hot with a wire tester.

After the confirmation, you need to take off the screw that connects the wire to your car speaker. A regular screwdriver will be enough for this job. Once done, take the exposed wires from the speaker and the subwoofer and wrap them together.

Finally, replace the connected wires and screw them to the speaker. Play some music on your stereo and check if the subwoofer is working properly. And your job is done!

The Best Way - Lower the Frequency with LOC

A line output converter or LOC is a small device that receives the high-level signal from your stereo and transfers it to a low-level signal for the subwoofer. You need to connect the LOC to your front and rear speaker. For this, follow the process given below.

  • To install the LOC, you must have a clear understanding of the speaker wires and LOC connection wires. Each four of your car speakers will have positive and negative wiring. Or, you'll find only two colored wires.
  • The LOC will also have 4 different wires for easy connection with the car speakers. If your vehicle has only two wires for the speakers, you can attach the two positive LOC wires and do the same for the negative ones.
  • After that, all you have to do is connect the positive wires of the LOC with the positive ones of your car speaker. And same will be applied to the negative ones. When you're done, check the connections properly and test the audio quality.

A Convenient Trick - Power the Subwoofer Using Your Car Battery

If you want to power the subwoofer independently from your stereo, this trick is for you. But first, you need to check your battery capacity and how much power is needed for the subwoofer you'll be using.

Of course, you can't apply this method if the sub needs too much power exceeding the battery capacity. Here's how it works-

  • Start with disconnecting your car battery and removing related delicate wires and other components. Now, find the negative and positive terminals of your car battery. Refer to the owner's manual for easy identification or use a wire tester.
  • Select the wires on the subwoofer to connect them with the battery. Strip off a small portion of the insulation cover from all the wires you're working with.
  • You can use a wire cutter if the cables are too large. Next, you'll need a wire connection kit to put together the wires of your battery and the subwoofer. When you're done, test the connection and turn on the stereo to check the sound quality.

Wrapping Up!

Now you know how to connect a subwoofer without an amp to your car. Of course, we recommend installing an amplifier with your sub for the best sound quality, deeper bass, and increased feel.

However, you can get away without adding any external amplifier if you got an active subwoofer in hand. For the best results, follow the methods we provided for an easy and quick subwoofer installation without an amp.

Related Guide You May Read:

Leave a Comment

12 − 6 =