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

An active subwoofer is all you need if you want to connect it with the car stereo. Is that kind of unbelievable? Yes, you don’t need an amplifier for this arrangement, and the sound quality will be great, but you must have jack wires and a powered subwoofer. 

Most of the time, the subwoofers come with an amplifier, and all you need to do is connect the system. This also boosts the sound quality and improves your listening experience. But if the subwoofer is active and yet does not come with an inbuilt amplifier, the sound quality will also be great. 

Tools/ equipment needed

Some of the necessary tools you need for the installation are- 

  • An active subwoofer
  • Jack wires
  • Screws to tighten these wires
  • Pliers to connect and disconnect the wires
  • A tester to check the current and sound quality
  • Rubber gloves for safety. 

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

Once you gather all the things, then you can follow the steps given here, and wear the gloves to protect your hands from sharp edges and electric current- 

  1. You do not want to get hurt due to accidents and shocks, so the first step is to disconnect the battery and speakers. 
  2. It is also important to switch off the ignition and battery as a sudden spurt in power may also damage the components of the music system. The entire electrical circuit may be damaged when the subwoofer is connected or tested. 
  3. Most cars have a fuse box that controls the power flow from the supply to the stereo. Remove it safely and keep it away until the wiring is complete. Again, this is important to ensure safety when you connect the subwoofer with the power supply.   
  4. Remove the speakers in such a way so that you can access the wires behind and underneath. Contact a professional mechanic if you don’t understand the wiring apart rather than connecting the wrong ones. 
  5. Once everything has been removed or kept aside, you can get more working areas and access the speaker wires. You must identify the right wires/ cables to connect with the subwoofer and remember the wires don’t connect directly but go through an adapter. 
  6. The adapter may be packed with the wires already with clearly marked codes totally, and you can easily connect the right wires with the ones from the stereo. The adapter supplies power to the subwoofer, and it is safer and easier to use the adapter to connect it.
  7. Once you have identified the wires and their connections, then you can connect the subwoofer to the speakers using the jack. The subwoofer helps to improve the stereo’s bass immediately, and you will enjoy the music with deep notes. 
  8. If you do not have an adapter and don’t want to buy one, the task will be a little more difficult, but you can still connect the subwoofer with the stereo. 
  9. You need a low-frequency effect jack on the stereo if you do not want to buy an adapter. The jack will connect to the output port of the subwoofer. Check that its label says subwoofer or sub out, and it is the only port so that you can easily recognize and connect the wires. This is connected directly without an adapter. 
  10. If the model is different, you must connect the right and left connectors of the stereo with those of the subwoofer. These may be marked L and R. the cables can be plugged into the correct points on the subwoofer box. The split end cables may also be plugged into the subwoofer’s L, and R marked points. Remember to connect the correct wires, keeping their positive and negative poles. Use the tester to check the current flow through the crossover and ensure there is no accidental short circuit. 
  11. In the case of a single cable with the connector, you can try with the right and left and find the right sound output. 
  12. A subwoofer and car stereo can be connected directly, which is too easy. But this changes the original wiring system in the car. Hence to ensure the safety of the electric wires, the subwoofer’s placement is critical.  
  13. The stability and durability of the subwoofer and the sound quality will depend on the same location. It is also important to ensure that the wires don’t move and get entangled or disconnected.  
  14. The subwoofer must be in a place where it does not move much, and the sound is good. Usually, people keep it behind the back seat or in the vehicle’s trunk.
  15. Check the functioning of the stereo system. Ensure before the test and double-check all the connections. Any loose connection or screw or wire may short the mechanism when you switch it on. Now you can keep the speakers back in their place. 
  16. Connect with the battery and switch on the ignition. Then you can switch on the power on the stereo and start some music at low volume first and then slowly increase that. If all the connections are proper, then the bass will sound better than before, and that too without an amplifier.   
  17. The subwoofer can be enclosed before keeping it back in its place. This will prevent damage due to movement and dust etc. 

Subwoofer Varieties And The Right One For Your Car

There are powered subwoofers with an in-built amp saving you space that two devices would occupy. Even though called powered, these are less effective than the ones with an amp. Another type of subwoofer is for drivers that are packed in a container but need an external amplifier.

Subwoofers are also designed for different models of cars, and you can choose the size according to the design of your car, budget, and space for the same. Round subwoofers are more common, but some believe that square ones are better. Check the compatibility with the space for the enclosure of the subwoofer. Also, check the subwoofer’s voice coils and sensitivity rating before buying the right one. 

Frequently Asked Questions

Q. How does a subwoofer work?

A. The primary function of a subwoofer is to improve the quality of sound in the audio system. It can produce deeper bass and dynamic sound that a normal speaker cannot. The audio system can struggle to reach its full potential and produce a flat sound quality without good subwoofers. 

Q. What is the role of an amplifier? 

A. As the name implies, the main function of an amplifier is to amplify sound. With an amplifier, you can get undiluted, smoother, and louder sound along with amazing bass. 

Q. Which is the best spot to place the subwoofers in the car?

A. There are several placement options available, depending on your preference and the size of the car. They can be placed behind the back seat or the trunk. The sound quality is influenced to a large extent by the shape of the interiors. 

Q. How long can a subwoofer last? 

A. Just like any other electrical item, the subwoofer also wears out after regular usage. Subwoofers may have an average life span of 4 to 6 years, depending on the quality. 


You can connect a subwoofer and stereo without an amplifier. Stay safe and use protective rubber gloves while fixing the same. Follow the steps given here and enjoy the deep sound of music. 

Liam Dare

As CEO of, my passion for the automotive world motivates me to build online businesses that provide information and entertainment to users. I am proud to contribute in a positive way to the automotive community.