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How to Connect a Subwoofer To Rear Speakers

This article will show you how you can add an extra subwoofer to your car rear speaker. This is a step-by-step approach to make installing a lot easier for you without professional skill.

Tools to Connect a Subwoofer to Rear Speakers

You will need a couple of technical tools for unboxing, connecting wires, and other procedures. A list of tools you might need includes:

● Screwdrivers
● Soldering iron
● Flashlight
● Connector
● Wire Cutter
● Hook toolset
● speaker wire

How to Connect a Subwoofer To Rear Speakers Step By Step

Self-installation of a subwoofer in your vehicle is a great way to get the job done faster. In this case, we will be connecting your subwoofer to your rear speakers. In other words, we will be installing the subwoofer in the car without an amplifier

  1. Placing your subwoofer is the first step to installing it successfully. Safely place the subwoofer behind the back seats or in the trunk. Although the back area seems the best place for the subwoofer, the placement is determined by how large the car is and the sound effect you are looking to get.
  2. This step is highly important for connecting the amplifier that powers the subwoofer. Run the amp wire to connect it to the car battery as a power source. 
  3. The next step is passing the wires to the car engine. This step may become the most challenging step for you but if you follow the instructions properly, it should come off very easy. Look around the car to locate the carpet edge you can raise. Run the wire under the carpet to the dashboard area.
  4. Use the flashlight to check under the dashboard to see if there is any space or hole through which you can pass the wire. After a careful and thorough examination, if you can’t find any hole, find a rubber seal that drives wire to the engine and gently make a hole in it. Your hand may not be able to reach the wires at this point, so use a hook tool to pull out the wire gently through the hole into the main compartment.
  5. After passing the wires through the length from the back to the engine compartment, the next step is connecting the wires to the car battery. The function of the car battery is to serve as a power source that generates enough power needed by the subwoofer. Gently trim off a small portion of the wire end (about an inch or half) and connect the positive wire to the battery. A rule to note here is the safety precaution that requires placing less wire into this area to avoid wire melting in a short circuit.  Following the safety rule, try not to connect more than half an inch to the battery terminal.
  6. Next, connect amp ground wire to an exposed metal near the position you have placed the subwoofer. Use a crimp ring to fasten it to the body of the bare metal with the help of a bolt or wide head screw that can hold down the wire.
  7. Connect the remote on wires (you will find this as a blue wire in most cars. Remote-on wires are always around the ignition area, they help to power on the audio device with the ignition on.
  8. To connect to the rear speaker, simply check the speaker wiring of the rear speakers to tap the audio signal from it. Check the trunk to expose the wires and strip the wire insulation to connect the subwoofer wire to it. Soldering might bring out the best result, however, to prevent damaging the wire, you can simply connect the wires with crimp connectors.
  9. Ensure all connections have been properly put in place. After confirming all necessary connections are done, bring all wires together and hold them together with a wire tie to avoid messy connections. If there is any excess wire at this point, cut out with a wire cutter and wrap connections in crimp connectors.
  10. Now that you have successfully connected all necessary wirings, it is time to connect the wires to both the amp and the subwoofer. First, remove the power wire fuse and turn off the power, now connect all the wires from the connections you have earlier made i.e. wire from the power wire, ground wire, and the remote-on wire to the corresponding sources. Your subwoofer should work perfectly fine with your rear speaker.

How to Connect Subwoofer To Rear Speakers Without Amp

Subwoofers require a strong power supply to run effectively. To cater to these requirements, some subwoofers have an amplifier built into them from the manufacturer, but some don’t have (you have to get an amplifier manually).

Here’s a simple step-by-step approach to installing a subwoofer to your rear speaker without an amp.

  1. Disconnect your car battery from the terminal (Make sure the ignition is turned off before this process).
  2. Unscrew the fuse box to make it convenient to access the power port for connecting the subwoofer to a power source.
  3. Remove the speaker from the fixed spot to be able to access the necessary wiring. Be very careful not to break the speaker wires
  4. Connect the subwoofer with an adapter to the speakers. The adapters make this process a lot easier without an amplifier.
  5. After connecting the adapter to the speakers following the corresponding ports, the next step will be to connect the subwoofer to the jack to establish a connection between the speakers and the subwoofer. Once these steps are followed properly, the subwoofer should work perfectly now without an amplifier.

How to Connect a Subwoofer To Speaker Level Outputs

Step 1. Confirm the specifications of the receivers and subwoofer to ensure compatibility and requirements. Although most receivers these days have dedicated ports for subwoofers’ output, it’s essential to confirm this before attempting to connect your subwoofer.

Step 2. Locate the output connection port for high-level audio. Run two speaker wires from the left and right of the audio channels to the front and back of the subwoofer (the regular way to connect subwoofers).

Step 3: Adjust the audio output (bass emissions) from the subwoofer by adjusting the filter to remove distortion and make the audio better. Adjusting the filter allows you to choose how you want the bass from the subwoofer to sound when in play.

One advantage of setting up this connection is that you will likely avoid the issue of having your speakers not working while the subwoofer works


Enjoying your music is a whole lot of fun with a connected subwoofer that adds the extra bass effect. Now you can enjoy those thumping low-frequency sound effects from your audio output through your rear speaker.