How To Install A Subwoofer In A Car Without An Amp - Tips & Tricks

The sound system in your car is one of the essential components. You can make or break your driving experience with it, and it’s also a great way to show off to your friends.

But if you want high-quality audio without breaking the bank, there are a few simple things you can do. This article will go over how to install a subwoofers in a car without an amp and other topics related to sound systems in cars!

How Can I Connect a Subwoofer to My Car Stereo Without an Amplifier

If you want a full-fledged sound system in your car but don’t want to break the bank, you can follow these steps on how to connect a subwoofer to a car stereo without an amp.

Your first step is to purchase a subwoofer. Believe it or not, this is the most difficult part of the process because there are many factors to consider. To learn more about choosing a subwoofer, check out this article on how to choose a subwoofer.

A subwoofer is not sufficient without a crossover network. The crossover determines how frequencies are split between your woofers and your tweeter.

As for wiring and cables, we would recommend using oxygen-free copper speaker wire because it is affordable and easy to work with. Also, make sure that your cables are long enough! You will need at least 15 feet of cable for a decent installation.

If you want to install your subwoofer in the trunk, make sure that it is securely fastened and will not slide around or rattle against other objects. You can use industrial velcro, wood screws with rubber washers, or even magnets if they are strong enough! It all depends on what kind of space you have in your trunk.

How To Install A Subwoofers In A Car Without An Amp Types

The subwoofer can be connected in two ways to the car audio system, depending on the subwoofer type

Passive Subwoofer

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

You will need to connect the speaker level inputs into your car stereo. If you are using a factory radio, this is fairly straightforward because they usually have preamp outputs for all channels except the subwoofer (LFE).

If you are installing an aftermarket head unit or amplifier in addition to your factory one, make sure that it has either speaker level or line-level inputs.

Active Subwoofers

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

You will need to run a set of RCA cables from your head unit into the subwoofer crossover, then connect the subwoofer’s speaker-level outputs to each woofer individually.

This can be tricky if you are installing this type of sub in an older vehicle where it may be difficult to find the factory speaker wires. Most active woofers come with all the necessary wires, so let’s get started.

  1. Disconnect the ground wire from the battery. Battery Safety Ensure that the negative battery cable is disconnected from the negative terminal of the battery. 
  2. To access the outlets on the rear panel of the stereo, remove the stereo from the stereo mounting dock. Disconnects the stereo wiring from the unit.
  3. Attach RCA cables to the head unit’s AUX input if you are using an aftermarket one, then connect it with speaker wire to the subwoofer crossover and plug in the power cable of an amplifier or 12V wire from the battery if there is no external amp.
  4. Then install new car speakers with the help of screws, bolts and wire clips.
  5. Place the subwoofer in a proper place, then connect it with speakers using speaker wires. Ensure your connections are clean and secure by tucking them into the vehicle’s stereo mounting dock interior panels or behind trim pieces.
  6. The last step is to adjust the bass level of the subwoofer until you get desired sound quality considering other sounds in your car.

Remember that many car subwoofers need an external amplifier, as you know. Active subwoofers are the most popular subwoofers that can be directly connected to your stereo system. The built-in amp in a powered subwoofer saves you time and space.  

Which Subwoofer Type Can I Connect a subwoofer in a car without an amp? Under Seat Subwoofers

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

You can install those under the seat because they are cheap and easy to wire, especially in situations where the trunk is small or cannot be connected to the passenger cabin. Make sure you put the subwoofer enclosure box in the trunk of your car.  

In sports cars with a centrally located engine, for instance, putting an enclosure in the trunk is impractical. 

Bass Tubes

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

Bass Tubes are great for adding bass speakers to the low end of any vehicle because they come in different lengths and they have built-in mounting brackets.

Satellite Speakers

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

You can connect satellite car speakers with or without an amplifier, but it is recommended that if your car stereo has preamp outputs and there is space in your trunk, you should put a subwoofer box.

Let’s start:

  • Disconnect the negative terminal of the battery to prevent shorting and causing injury or vehicle damage.
  • Remove the factory radio from your car – it is easy if there are only two bolts holding it into place. 
  • Install new speakers with the help of screws, bolts and wire clips.
  • Place the subwoofer in a proper place, then connect it with speakers using speaker wires. Ensure that your connections are clean and secure by tucking them into the vehicle’s interior panels or behind trim pieces.
  • Let’s adjust the deep thumping bass level of the subwoofer until you get desired sound quality considering other sounds in your car.

Spare Wheel Subwoofers

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

Installing a subwoofer in the trunk will allow you to utilize this space. If you do not have a spare wheel, you can place a subwoofer inside the spare wheel.

How Does A Car Subwoofer Work

How To Install A Subwoofer In A Car Without An Amp by speakerjournal.com

The subwoofer in your car will produce low-frequency audio that you can feel but not hear. This is because the human ear has a difficult time hearing sounds less than 20Hz (20 cycles per second).

To put this into perspective, 20Hz would be equivalent to 0.02 miles per hour! Without getting too technical, let’s take a look at how car subwoofers work.

A speaker cone in your car, whether it is for the midrange or bass frequencies, consists of two types of things: magnets and wire coils. The magnet creates a magnetic field that interacts with the electric current passing through wires to create loud sound waves.

Therefore, if you have low-frequency speakers, you will need a heavier magnet to get the job done. Additionally, since there is not enough room in your car for an enormous speaker cone that can produce low-frequency audio without distorting it beyond recognition or causing injury from high volume levels, most cars do not have subwoofers installed.

Conclusion

As you can see, there are different solutions for every type of subwoofer. If your car has preamp outputs and enough space in the trunk or under the seat, go with a box enclosure.

Otherwise, choose the option that best meets your needs!

FAQ's

How to connect a subwoofer?

You can do this with RCA cables. Connect the head unit’s AUX input if it has one and connects it to the subwoofer crossover.

If your head unit does not have an AUX input, you can wire in a new one and connect it to the subwoofer crossover.

How do you wire a sub into an existing factory radio and amp?

It is recommended to use the factory amp. If it is not possible, you can purchase an amplifier and connect the subwoofer crossover to that.

How do you wire a subwoofer without an amplifier?

If the head unit has preamp outputs, just connect them to it. If it does not, you can install a new head unit with preamp outputs and connect the subwoofer crossover to it.

How do I attach a subwoofer to my car?

Usually, there is a box in the trunk where you can install it. If that isn’t possible, you can put it under a seat.