Car Subwoofer Installation – All You Need to Know

When you want to improve your car’s sound or stereo system, it’s essential to understand what equipment you’ll need to make your vehicle produce the best sound possible — and subwoofers are your best choice. Investing in a sub is one of those simple upgrades that improve your vehicle’s audio quality drastically. Plus, subwoofer installation is a fun project to tackle over the weekend, saving you money and helping you achieve the booming bass sound that lets you have a better ‘feel’ of your favorite songs.

A subwoofer frees you from having to settle for the lesser-quality sounds your car’s regular speakers produce and from massive sound systems that cram your vehicle. You can get smaller ones in sets to enjoy a genuine surround sound experience, allowing you to enjoy your favorite tunes and the buzzing wood of your speaker more. You can install a subwoofer yourself, but it will take patience, time, and a lot of effort. However, it can be an enriching experience.

If you’re considering installing subwoofers for your truck or sedan, here’s an in-depth guide to help you out, streamlining the process, helping you produce the best sounds possible, making your car rides more fun and memorable.

Basics of Subwoofer Installation

When it comes to working on a subwoofer speaker, despite it coming in a broad range of sizes and shapes, the most common ones you’ll encounter are unpowered (component) and powered subwoofers. An unpowered subwoofer doesn’t use a built-in amp as a power source, meaning you need to connect a subwoofer to an external amplifier to work and draw an electric current. Meanwhile, a powered subwoofer is a portable sub with a built-in amp, so you don’t need to attach it to an amplifier. All you need to do with this is connect its power cable to different vehicles’ stereo system, making it perfect for a pontoon boat, SUV, and a regular car.

Both subs require a sturdy enclosure for it to work correctly. Luckily, there are plenty of ready-made boxes available for different sized subwoofers. Plus, they don’t take as much space as regular speakers and a separate amplifier as they boast compact designs, meaning you can place them either in the car underseat or in the trunk. However, remember to anchor it properly because it may cause injury when you abruptly stop, leaving it flying out of its place.

When installing a sub and an amplifier, the most crucial element you need to watch out for is the snap. You’ll need to have a proper subwoofer box for the subwoofer to help you mount it by connecting the leads to the terminal cup. After that, utilize the mounting screws to place the speaker in place tightly. After placing the subwoofer, you’ll need to run the wires to a nearby amp, and you can choose to wire it however you want. However, the most recommended method is wiring it in parallel or in a series for a higher impedance setup or when you plan on installing several subwoofers.

How to Install a Subwoofer in a Car

Subwoofers can significantly enhance a stereo system’s audio output, but you need to use it carefully as it can overpower everything else when you misuse it. However, when you use it judiciously, it can enhance the whole experience indefinitely. These are far more complicated to install and fine-tune than everything else in the car audio system — but learning how to install a subwoofer is achievable.

Here are different steps to installing a subwoofer:

1. Pick an Amplifier and Speaker

The first thing you need to do is choose a speaker and amplifier that work together with their best power without overwhelming each other. To find out how compatible these two components are, you need to place the amplifier and subwoofer speaker’s Root Mean Square (RMS) as close as possible. The RMS refers to the amount of power the speakers can continuously emit without going “bad” and how long an amp can function without overheating. A 4 Ohm amp is also ideal to use as it is stable and produces the best sound quality possible.

You don’t need to look at their peak power at this point. That’s because you can only run a sub or amplifier on the peak power for about a minute before it malfunctions. You will want to run your subwoofers on their RMS rating rather than their peak rating. Besides the RMS, choosing the size for a subwoofer is also crucial, as smaller speakers like the 8 to 10-inch ones are fast to respond and ‘punch’ better than the bigger ones but aren’t as loud.

Meanwhile, massive speakers like those larger than 15 inches are much louder than the smaller versions with the same wattage but have a slower response, meaning the sound quality is significantly less. However, they can handle lower frequencies better. Additionally, ensure you purchase a subwoofer box with a hole the same size as the speaker for the best results. Choosing between a small and big subwoofer will depend on your specific needs and your car’s size. Usually, if you have a sedan, an 8 or 10 inch sub is ideal, but if you have a truck, a 15-inch speaker is perfect.

2. Run the Wires

After finding the best sub and amp pair, you’ll need to start using your wiring kit that should contain basic tools, including hand tools like screwdrivers and a coat hanger. Begin by adding the wire to the battery. Tip, avoid placing the wire from the fuse box as it’s often too powerful, and you might hear the car engine compartment noise amplified through the speaker. Plus, some stereos can easily blow a fuse.

Remove the insulation off the wiring at the end where your battery is, then wire its in-line fuse. Tape the place where you wired the fuse to the power cables so you don’t get short, then run the remaining wires under the car’s carpeting or its wire channels if it has one. While doing this, run a 16-18 gauge wire and its RCA cables from the trunk to the back of its aftermarket head unit.

3. Wire the Sound System

After running the wires through your cars, now you’ll need to take the stereo head unit out. On its back, it should have two RCA connections. When you spot them, run your RCA cables through the unit’s back center and plug them into the RCA connections on the back. If you don’t see these designated RCA connections, you’ll need to splice the wires into the rear speaker wires.

4. Wire the Remote

After connecting the RCA wires, now you’ll need to run the 16-18 gauge wire through its back too. It’s responsible for telling the amplifier when a stereo turns on, allowing the amp to turn on also. Before attaching them, take a look at the speaker wires coming out of the unit head’s back, and you should see a blue wire (remote wire) or two. If there are two wires, one wire should be labeled “amp,” but if there is only one wire, use that. After spotting the blue wire, you’ll need to connect the 16-18 gauge wire to it, so when the subwoofer turns on, so will the amplifier.

5. Place the Stereo in a Subwoofer Box

If your stereo or speaker is already in an enclosure, skip this step. However, if it doesn’t, continue. Place the stereo in the box while ensuring the thin gasket part is on it. If the enclosure has its connectors on its exterior, ensure to wire the speaker inside. Screw the speaker inside the box using the drilling holes on the speakers’ outside rims, then set the enclosure where you’d like (either the trunk or under the seat). Some places to consider also include the firewall or the passengers’ door side or edge.

6. Wire the Amplifier

Now that you have most of the wirings in place, you need to wire up the amp. Connect the power cable from the battery to the amplifier’s spot with the markings B+, +12v, or a power. Then connect its 16-18 gauge cable into the place with a marking saying ‘Rem.’ Put its 3-foot ten gauge cable to the marking B-, -12v, or ground. Connect the other end of the ground wire to a bold connecting to the car body. Then connect the speaker wire the + and – mark the amplifier and its other end of the same markings on the enclosure.

7. Add Power

Now that you have all the wires in place, your last job is to connect the speakers’ power cable to the battery. You can shove the wire between its clip and post on the battery, then make sure the fuse is in the right holder, and you’re done!

How Much Does Subwoofer Installation Cost?

If a subwoofer install task is out of your comfort zone or you don’t want to fool around with the installation, you can hire a service or an individual to do it for you. However, when choosing a provider, ask yourself first how much you can trust them. After all, having a sub installed is no easy feat, and you’d typically want the best results. When choosing an installer, make sure they have the right experience and have insurance to ensure they can cover the damages if they make a mistake on your car or its components. The rates that installers charge varies on what type of installation you’re looking for, such as you only need to install the subs themselves or a whole amp and sub setup. But generally, they charge over $100 for installing a sub woofer.

If you have the essential items and basic tools but don’t wish to mess around with the car installation process and don’t want a newbie to do the job, hire a reputable service provider to install your subs and amp. Plus, it’s better to buy some or all of your components from the same dealer who will install them for you, saving you money in the long run.

How Long Does a Subwoofer Installation Take?

Installing a sub in a car is hard work, and the length of completion varies on the vehicle or how many people are working on it. However, generally, installing an amp and sub can take between 3 to 5 hours, but when more individuals are working on it, it’ll only take 1 to 2 hours. But if you’re planning on adding subwoofers to a factory system at home, expect it to take longer. Moreover, installation in larger vehicles such as SUVs or trucks, will usually take longer than sedans, such as a Honda civic or Volvo xc90.

Besides the vehicle type, how many people are working on it, and the setup steps, the car model also plays a role in how long the project can take. Even if shops or individuals are very well qualified and have plenty of experience installing subs, some car models are more complex than others, prolonging the process. For instance, for a BMW e46, the wires you need to place on are already in the trunk.

Plus, it’s already next to its factory amp, meaning if you only plan on adding a sub and enclosure to the factory stereo, you’ll need to splice a converter to the rear speaker wire in front of the trunk. You don’t even need to take out the factory head unit since all the wiring is already in the car’s rear, drastically shortening the process.

In essence, the time it takes for a sub installation to finish greatly varies on several factors, including the wire diagram and the demands of the job itself, so it’s best to prepare for it for a day.

How Much Does Best Buy Charge to Install a Subwoofer?

In Best Buy, you can have a subwoofer installed by Mobile Electronic Certified Professional (MECP) auto technicians, and you ensure your subs get installed neatly and efficiently, giving you the best performance possible. The components’ cost will vary for a single installation, and such parts plus additional items will cost you extra. The auto technician will typically give you an estimate before performing a job that requires additional charges, including non-standard installation. Generally, sub installations alone typically cost around $19.99, while amplifier and subwoofer installation can range between $119.99 to $129.99.

When you hire professionals from Best Buy, they’ll typically go through a pre-installation checklist, and if they deem it necessary, they’ll also remove your pre-existing subwoofer. They will then wire the subwoofer and box ring terminals and ensure the sub is fastened securely to the enclosure. To finish off, they’ll also perform a post-installation checklist, clean the work area, and demonstrate how your subwoofer works and introduce you to its different features.

When you directly order from Best Buy, you’ll get a redemption email sent to your email address or account containing a code validating your order. After this, you’ll need to go to your nearest installation center and schedule an appointment that’s most convenient for you.

Does Walmart do Subwoofer Installation?

Walmart offers vehicle subwoofer installation services for only $44.99, but take note that this only includes installing the sub to an existing factory stereo head unit or amplifier. As a customer, you’ll need to provide the amp’s enclosure and power wire. Keep in mind that a powered or amplified subwoofer isn’t included in this car subwoofer fitting. You’ll need to buy an amp with two channels or avail of mono installation service for the particular unit with those features. Additionally, some vehicles require additional labor and parts because of their wiring complexity and accessing some replacement items.

Meanwhile, if you’re looking to have whole speakers installed, the professionals will remove your existing stereo and install a new pair of speakers. These replacements are typically the same size as the previous factory mount locations in your car. Other services include connecting wires to the battery to amplify your car’s stereo. The total cost for the amp and sub installation is $64.99. However, keep in mind that some vehicles may need additional work or parts, depending on your car’s wiring complexity. All in all, the stereo system installation offered by Walmart ensures expert service and maximum convenience, helping you improve your subs’ sounds in no time.

How to Wire a Subwoofer

Is there any difference from wiring regular speakers and how to wire a subwoofer? There is no difference between the two, except that the subwoofer usually has its own amp.

Installing a subwoofer requires some knowledge of electronics. If you don’t know anything about a car’s wiring, you might damage the subwoofer, cause a fire or damage your car’s electrical system. You need to know the amp’s power output and minimum impedance, and the speaker power rating and impedance. You also need to plan whether the speaker wiring will be in parallel or series.

Calculate the electrical values for the speakers and the amplifier output. Check your amp specifications for the output power in watts, and the minimum impedance in Ohms. Write this down as you will need these later. The speakers will also have an impedance value (also in Ohms) and the maximum power impedance it can handle (in watts). Beware that if you speakers receive more power than it is capable of, it will get damaged.

To calculate the total impedance of your speakers wired in series, add all the impedance values. If your speakers are in serial, the formula is: ((Z1 x Z2 x Z3 …) / (Z1 + Z2 + Z3 + …)) = total impedance. You can play around with a mix of series and parallel connections based on the amp impedance. Ideally your amp impedance should be equal to the speaker impedance. A speaker assembly with a lower impedance than the amp’s output impedance can cause impedance mismatching, resulting in damaged speakers.

Create a wiring diagram based on your calculations above. You will need to follow this because it can be difficult to keep track of the wires going to and from the speakers. You can have all your speakers in parallel, or all in series, or these can be in a mix of series and parallel connections. Take note which speakers are in series and which ones are in parallel.

Unplug your battery terminals to ensure that your car’s electrical system is off. Physically remove the cable from the battery terminals.

Wire the first speaker to your amp. Follow the wiring diagram you created and connect the second speaker, and other succeeding speakers. Close the loop by connecting the last speakers to the negative port on the output jack on the amp.

After double checking that your cables are not short-circuited, you can connect your battery cables to restore power to your car. Test your work by turning on the sound system.

How to Install Amp and Sub

Installing car subwoofers is the best way to improve your car’s audio system, greatly enhancing your driving experience. So, how to install amp and sub? Gather your hand tools and amplifier wiring kit — and follow the steps below to install amp and subs in your car.

  1. Disconnect the Battery Connection and Mount the Amp
    Set your car’s parking brake and disconnect the battery’s negative terminal to protect you from any electric shortage or shocks. After ensuring it’s safe, mount your amp in the location you’ve chosen. Ensure it has enough room inside for the amp to allow free air to pass through it to prevent overheating.
  2. Install the Power Wire
    The power wire from your wiring kit needs to run from the battery through your car’s sides or firewalls, through the car’s body then to the amp. Search for an unused grommet in the firewall or one with existing speaker wires passing through it while having ample room for the wire to the battery to fit through too. If you can’t find one, grab your speed drill to make holes through the firewalls, but ensure you don’t hit any electrical or gas lines.The power cables you’re using may need to have a holder installed. If that is the case, make sure you connect the wire to the fuse holder beforehand. Attach the power cable to its positive battery terminal, not the post itself. If you have top-mounted battery posts, the most common way you can connect the power wire to the fuse by crimping a ring terminal onto its ends.
  3. Install the Fuse Holder
    Search for a good place close to the battery to put the fuse holder. A tip to remember is that even if a fuse malfunctions, the gap between the battery and holder will still be working and can be a fire hazard, so make sure to change cables immediately when this happens.
  4. Connect the Ground Wire
    You need to connect the ground cables as near to the amplifier’s location as possible and find a bolt suitable for your car’s metal frame to use. If you can’t find one, you can drill a hole for one, but be careful and not drill into any wiring or brake lines. Crimp a ring terminal to the short end of the ground cables, place it to the terminal, then use a lock washer to keep the connection secure.
  5. Add the Remote Turn-on Wire
    The turn-on wire (remote wire) is usually blue or white, which will signal your amp to turn on whenever you turn on the stereo. You’ll have to remove the speakers entirely to get to this wire. After that, strip its insulation into a smaller connection and connect it with the turn-lead from your wiring kit using a crimp connector.
  6. Creating the Signal Connections
    If your in-dash receiver has pre-amplified RCA outputs, connect your RCA cables to them, then route them to the opposite side of the car from the power cable. It’s crucial to separate these cables from the power wires to prevent potential noise issues, though some don’t follow this tip, leading to a complete reinstallation.
  7. Speaker Wiring
    You need to provide a way for the sounds to get from your new amp to the speakers. When doing a DIY process, run a new speaker wire from each output to each speaker, using 14 to 16 gauge wire for speakers or 12 to 14 for subwoofers.
  8. Connect All Cables
    Neatly drape or trim all wires using a coat hanger and connect them to the amp. Make sure to create gentle curves with the cables and not sharp ones that can pinch. Some people cut small slits in their car’s carpeting and run the wires for a stealth installation.
  9. Double-Check
    Before turning it on, check the source for all the wirings, from the battery to the speakers, ensuring all connections are tight and secure with no stray wire strands. Turn on your car and radio, and see if the system produces the ideal sounds. If you see something is wrong, re-check the steps if you missed anything.

How to Hook up Sub and Amp

Every audiophile knows that a stereo isn’t complete until you’ve added a sub to your speaker system. The subwoofer is a speaker specifically designed to provide precise sound to low-frequency audios like bass sounds. However, how to hook up sub and amp? Whether you’re installing the sound system to a Mercedes w210 or trucks, the installation steps of connecting subs and amps are the same.

Start by turning on the amplifier and the subwoofer to let the back face you. When you do this, you’ll be able to clearly and accurately see the labels on its exterior, output (jacks), and plugs. Find the plug on your amp labeled ‘sub out,’ ‘LFE out,’ or ‘line out.’ These sites are also called the ‘terminal,’ used to connect the sub and amp. After this, hook up the cables included with the subwoofers to the amplifier’s terminal. You can also connect them with the RCA cables. Connect the wire ends to the battery terminal on the back of the sub marked ‘line in.’ Then, insert the audio discs that have deep bass sounds and test it out by pressing play. When listening to the audio, adjust the volume until you’re happy with the bass tones coming out of your subwoofer.

How to Hook up a Subwoofer

The subwoofer connections used for cars follow a two-channel system, significantly differing from the methods used for church sound systems for home theaters. So you may ask yourself, how to hook up a subwoofer to a car? AV receivers provide bass management, directing the low bass sound frequencies to the subwoofer and the midrange to treble frequencies to the stereo. Then you can hook up the subs to the receiver using a single interconnect cable.

However, stereo receivers, preamps, and an integrated amplifier don’t have subwoofer jacks. Instead of using these connections, you can use the sub’s high-level input. You connect them using speaker wires to the same stereo output jacks on your amplifier hooked up to the speakers, meaning you need to double up the connections.

With this wiring, expect the stereo speakers and subs to receive all frequencies, ranging from bass to treble soundwaves. The subwoofer will then use its built-in crossover filter to determine the sub’s frequencies’ upper limit. With small stereos at 4 inches or small woofers, you need to set the crossover frequency at 100 Hertz, and with speakers with 5 inches or larger woofers, 80 Hertz will do. After this, set the volume control to provide the level of bass support you’d like.

How to Connect Subs

Subs are usually easy to install since they only have two cords: a remote wire to connect the power and the other for the audio input. You’re likely to spend more time looking for the ideal position and adjusting a subwoofer for the best output possible rather than hooking up a couple of cables. So, how to connect subs? There are several ways you can do this, but the most preferred method is through the subwoofer output, which is typically labeled as ‘sub out’ or ‘subwoofer’ of a receiver using low-frequency effects (LFE) cables. The LFE port is a ‘special’ output only for subwoofers. Most stereo receivers have this kind of wire.

Connecting subs following that method only require you to hook up the LFE jack on the amplifier to the ‘line in’ or ‘LFE in’ part on the subwoofer. It’s usually only one wiring with RCA cables on both ends. However, remember that not all subs are simple and straightforward, and depending on the specific model, you’ll need to connect them using high level outputs. If this is the case, you’ll find the subwoofer to have spring clips to use the speaker wire, then use the receiver’s speaker output to connect it all up.


Installing a subwoofer in your car, whether it’s powered or unpowered subs, can make a huge difference in its stereo system, improving low-frequency reproduction and helping you ‘feel’ your favorite music and sounds better. These speakers often feature an integrated amplifier, speaker driver, and custom enclosure, designed to provide the best performance possible for your vehicle. However, the most challenging part of this is installing it, and though you can install the subwoofers yourself, it isn’t always necessary. You can always find a professional audio installer or a handyman to help you out.

Hiring a pro to install a subwoofer and amplifier in your car can save you a lot of time and money in the process, plus the work goes faster. Moreover, the sound quality that a professional can get you will also likely be better than what you get for yourself. However, it can be a fun and educational challenge for many DIY newbies, giving you an idea of how these speakers work and let you resolve potential issues swiftly in the long run.

We hope this article helped you better understand the process behind installing subwoofers, how you can do it yourself, and the best options for professional installations for a better, bolder, and powerful car sound system — helping you cruise in style.