How to Connect a Subwoofer to Car Stereo Without Amp

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Long drives can be very dull, especially if you don’t have company. Listening to your favorite music while driving kills the monotony and makes your trip memorable. Connecting a subwoofer to your car stereo without an amplifier can be challenging, but it’s not impossible.

What are Car Amplifiers?

A car amplifier is a device that helps boost small audio signals to big signals. Amplifiers are very efficient in improving sound quality. Most subwoofers require amplifiers for optimal performance, but some work even without amplifiers.

One advantage of using a car amplifier with your subwoofer is that it improves music quality, ensuring you experience high-quality sound. Amplifiers also maintain music quality even after you turn up the volume. They improve bass by making it louder, giving you a better sound experience.

The main disadvantage of using a car amplifier is that it consumes a lot of power. On average, amplifiers consume 100 to 200 watts of electricity per hour.

What is a Subwoofer?

Subwoofers are bass speaker systems that are designed to have lower frequencies. A subwoofer makes it possible for you to hear all the different ranges and notes of music.

They help improve the bass in music and produce music of high quality.

There are two different kinds of subwoofers:

  • Active subwoofers
  • Passive subwoofers

Active Subwoofers

An active subwoofer, also known as a powered subwoofer, is designed to produce low-pitched audio or bass. It houses the speaker and amplifier in the same subwoofer box, which depend on each other for optimal performance.

If your subwoofer is active, then your work becomes very easy. All you need to do is to plug the subwoofer’s jack wire with the stereo, and you are all set. You can now jam to your favorite music.

Passive Subwoofers

Unlike active subwoofers, passive subwoofers cannot function on their own. They require powering by an external amplifier or AV receiver to function. A passive subwoofer needs a lot of power to sustain the bass effect without draining the amplifier’s power.

So Why Use a Car Subwoofer?

Several advantages come with car subwoofers that you would ideally not get with regular speakers. The main benefits of using a car subwoofer include:

Deep Bass

A car subwoofer provides you with a deep bass that is not exaggerated. Deep bass means better quality music. You will find yourself swaying your head to the tunes as you drive. What better way to start your day than in a jolly mood?

Low-frequency sounds

With a subwoofer, you are guaranteed depth to your music, making it feel real. The low frequency helps ensure that your music is of sound quality. You enjoy the music more if the bass sound is well regulated.

Reduce Distortion

Playing music at a high volume may lead to the distortion of the woofers as they may not synchronize with the mid drivers and tweeters.

Takes the Load off Small speakers

Subwoofers enable the frequency to be well distributed. The small speakers now produce sound in a normal range, thus improving their performance. The sound that is produced as a result is of high quality.

They are easy to set up

Installing subwoofers in your car is not a challenging process. It is relatively easy, and you can do it yourself if you follow the instructions below.

Technician installing the car speaker

Which Subwoofer Can You Connect If You Don’t Have an Amp?

An active subwoofer is the best subwoofer to use without an amplifier. You are guaranteed deep bass and clear sound with an active sub, even without an amplifier.

Subwoofers come in different forms, sizes, and shapes, including under-seat, bass tubes, and spare wheel subwoofers. You can do your research to get one that suits your specific needs.

Under-seat Subwoofers

Under-seat subwoofers are the preferred subwoofers for cars with limited space in the trunk. An example of under-seat subwoofers is the one used in sports cars. This subwoofer is slim and is therefore ideal for small cars.

Bass Tubes

They are called bass tube subwoofers as they come enclosed in a tube. They provide you with great bass and take up very little space. Bass tube subwoofers are suitable for you if you prefer a softer sound.

Spare Wheel Subwoofers

As their name suggests, these subwoofers are installed inside the spare wheel compartment. The great advantage of using these speakers is that they use very little space. You can place them in your trunk and still experience quality sound.

How to Connect a Subwoofer to a Car Stereo

Here is a step-by-step guideline on installing a subwoofer to your car stereo if you don’t have an amplifier.

  • Find a good place in your car to mount the powered subwoofer – The subwoofer should be placed where it is easily accessible. In addition, the area should have adequate ventilation. This is because amplifiers may generate heat if placed in a spot that is not poorly ventilated.
  • Disconnect the Negative wire Terminal – This helps protect you and your gear from any accidents during installation.
  • Run the powered cable from the battery to the powered subwoofer
  • Cut a short piece of the cable – The cable should be enough to cover the distance from the battery to the fuse holder.
  • Strip off both ends of the cable – Keep the fuse close to the battery. This is because the subwoofer terminal between the lead and the fuse is unprotected. Pass the power cable through the firewall separating the engine compartment from the main cabin through the entry point. Place the powered cable under the carpet and ensure you reach the powered subwoofer.
  • Run the turn-on wire and signal cables – Ensure that the turn-on wire and RCA signal cables should are connected to your stereo. The turn-on wire connects to a blue remote turn-on wire on the stereo. Plug the RCA cables to their right RCA outputs.
  • Run the power wire and the RCA cable down the side of the car opposite the power wire to prevent electrical noise from disrupting your music.
  • Connect the speaker wire to the amplifier and reconnect the negative terminal of your battery

There you have it. Making these connections requires at least some basic understanding of wires, terminals, and tools such as a wiring kit. If you are unsure how to go about the whole process, we recommend calling in a professional.


It is important to note that the subwoofer performance depends on how well it is connected. A poorly connected subwoofer might produce harsh sounds instead of the expected louder and distortion-free sound.

In summary, connecting a subwoofer to your car helps increase the music’s bass and makes music enjoyable while driving. Subwoofer performance and sound quality depend on how well you connect the sub to your car’s stereo.

The process of connecting a subwoofer to your car is not complicated. You can do it yourself or call a professional to help you if you find the process challenging. One should research the best subwoofer type for excellent results before buying one.