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

Norvan Martin
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Subwoofers put your sound on a higher scale with their extra bass and the premium sound quality they add to your regular car stereo. However, can you use and enjoy a subwoofer in your car without using an amp? The short answer to this is yes!

An amplifier is a part of a speaker that helps you amplify the sound received by the speaker. Therefore, if you think your stereo is loud enough, and you just need extra bass then you don’t need an amp.

This article will show you the different ways you can use your subwoofer without an amp and strategic places to place them in your car.

Hooking Up a Subwoofer Without an Amplifier (Step By Step)

Your subwoofer needs an important power source to amplify the sound it receives efficiently. This is the importance of an amplifier. However, some subwoofers do not require an extra power source. They are referred to as active subwoofers.

To use an active subwoofer, simply connect it to your stereo and you’re good to go. Although an active subwoofer works directly, there are two types of active subs you can use with your car stereo.

Check out below for more details:

Passive subwoofers

It is very direct and easy to install in your car because they do not have a built-in amp. The connection is as direct as connecting an ordinary speaker to the stereo set.

To connect the subwoofer to the stereo, simply run a wire to connect the speaker end of the subwoofer to the speaker connection joint of the stereo and that’s all.

Powered subwoofers

This speaker has parts that make its connection almost the same as connecting a standard amp.

However, connecting the powered amp is also very direct since it requires no extra connection. To connect the powered amp as a non-professional, simply follow the following easy steps to guide you;

  • Separate the batteries from the ground wires to ease the process.
  • The next step is to drive your subwoofer wire to the power cable point of your battery. This connection has to be carefully arranged to prevent damage while in use.
  • Now that you’ve connected your subwoofer to the power cable of your battery, the next step is to connect the car stereo RCA wire to the subwoofer terminal. An important point to note while doing this is that the power wire and the RCA wire have to be connected separately to avoid sound distortion.
  • After you have successfully connected these basic cables, you can now connect the ground wires you have disconnected from the battery back to its port

If this process is followed to book, your powered subwoofer should work very perfectly. If it doesn’t, go through the steps again to fix any error you might have made.

How To Connect Car Subwoofer To Home Stereo Without An Amp

Connecting a sub with a home stereo if done wrongly could damage your car stereo and at the same time works very fine, it all depends on how you do it.

The first thing to note when thinking about connecting a home stereo to a car subwoofer is the difference in ohms.

Most car subs come with a 4-ohms capacity, however, most home stereos have an 8-ohms requirement. Therefore, without a good amp, the car subs may be exposed to instant damage at first use with the home stereo.

Here is how to use the car subwoofer with the home stereo safely without an amplifier;

  • Ensure it meets the resistance requirements of the home stereo
  • Use two 4-ohms speakers in series to meet up an 8-ohms requirement
  • Use a low pass crossover to block out high current coming in from the home stereo

Where To Place A Subwoofer In The Car

For maximum satisfaction, you should consider using your car stereo very close to you where you can listen to those low-frequency sound delivery.  

However, where you place your car subwoofer is determined by two factors; the size of your car and the type of the subwoofer.

The temporary space where you can place most subwoofer types is under the seat; between the driver’s seat and the passengers; in the trunk. Examples of these subwoofers are;

Subwoofers for under the seat

These subwoofers are specifically designed for small cars with limited space. It is flat and with an upper-section speaker that makes it ideal for placing under the seat.

Bass tube subwoofers

Some cars are much smaller with limited space in the car. Bass tubes are very ideal for cars with limited space because they can be placed anywhere in the car. They are very mobile and adaptable to anywhere you can get space to place them.

Subwoofers for Car Trunk

A trunk is also an excellent place you can use for your subwoofer to get quality delivery. Spare-wheel subwoofers are ideal for the trunk to adapt to the space and produce that jumping bass effect for your car.


Are Subwoofers Important In The Car?

Whether or not subwoofers are important in a car is a question that needs to be answered personally.

However, it is a consensus that sounds without bass are pretty much flat. Subwoofers have the special ability to pick up those low-frequency sounds and rhythms that a  regular stereo won’t deliver. Another merit of the subwoofer is the bass production that adds beauty to the sound production.

Thus the simple answer will be “yes! It is important, and you might want to add one to your car.

Are Subs With Built-in Amps Good?

The bigger the amp power, the better its amplification power. Since amps are important for boosting sound production, obviously a sub with an already built-in amp is a good choice.

They are an excellent choice of active subs and are often referred to as powered subwoofers. They save you the extra work during connection by simplifying the stereo-amp connection process.


On a final note, subwoofers can very much be powered by the possibility of an amp. However, when using an active sub, it is important to know whether they are passive subwoofers or powered subwoofers. Active subs are simple to connect to the car stereo but it must be done in a step-by-step order to get the best result.

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Norvan Martin is the founder of He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin