How To Build a Subwoofer Box To Specifications

Contact the manufacturer or dealer for the correct volume and placement of the subwoofer enclosure. Some subwoofers cannot be used in certain types of subwoofer enclosures and have very tight tolerances for enclosure volume errors. If a sub is installed in a subwoofer box larger or smaller than what is supposed to be, it will sound bad and could be destroyed. Subwoofer boxes and subwoofer boxes can be built in any shape, but complex shapes make it difficult to calculate the volume.

Different materials are required for the construction of subwoofer boxes and subwoofer enclosures. A subwoofer box must be very rigid. The most common building materials are 5/8 inch or thicker particle boards or medium-density fibreboard. If you’re building a Plexiglas subwoofer box, don’t use anything less than 1/2 inch thick.

No special skills are required to learn how to make a subwoofer box for home or for a car: even a beginner can do that (especially if you have all the necessary tools) if you follow the instructions to the letter. Basically, it’s a simple woodworking project. A properly constructed enclosure will ensure richer bass and improved bass response, as well as extending the life of your subwoofer by preventing damage and over-excursion.

A common material used to mold complex-shaped subwoofer enclosures is fiberglass, but it’s a real agony to work with and requires multiple layers to create a solid finish.

Learning how to build a subwoofer box allows you to customize the fit and design of the box to match your desired audio quality. The basic subwoofer box designs are sealed and vented. This article details how to build a subwoofer box, which separates the front and rear sound waves to improve the bass.

Types Of Subwoofer Box (Enclosure)

There are different varieties of subwoofer boxes with specific designs. Different box designs produce different kinds of bass notes suitable for either car stereos or home theatre systems. Let us learn about them further:

1. Sealed/Closed Box

SealedClosed Box

sealed or closed box is built tightly and is best for music that demands precise and defined bass. It produces a deep bass sound, flat response, and superior power handling. A sealed enclosure requires more power, thus for best performance use an amplifier with sufficient wattage.

2. Ported Box

Ported boxes utilize a vent or a port to augment low bass response. In other words, with a ported box, you force out the bass tones. They are suitable for music such as rock, metal, or any hard-driving music. Ported boxes are more efficient and are capable of delivering a deeper bass compared to the sealed boxes, but they should be larger in size to accomplish that.

3. Bandpass Box

Bandpass Box

Bandpass boxes are a variant of ported boxes but intended for a maximum slam. The subwoofer is placed inside the box and the sound is received through the ports.

The sound produced with a bandpass box is loud but has a narrow frequency range. Bandpass boxes are highly efficient but can be larger in size. Their dynamic sound is great for rap, reggae, hard rock, and the like.

4. Free-Air Subwoofer Box

free-air subwoofer box does not require a particular enclosure to work efficiently. In a free-air enclosure setup, subwoofers are installed on a board to be placed in the backseat of a car or the trunk. The sound quality in a free-air box is, however, compromised.

But if placed inside the trunk, it acts as an enclosure and eliminates the issue of distorted sounds. These boxes are convenient if you are short on space and are relatively easier to install. But these work only with subwoofers designed for free-air use.

With that, we can gather, the best box design for deep bass would be a sealed box or a ported box. The ported box, however, should be much larger in size than an average sealed box to accomplish a deeper bass.

Can You Build A Subwoofer At Home?

Yes, you can make your own personalized box to fit your subwoofer. However, you will need enough knowledge of enclosure dimensions, technical sound engineering, and craftsmanship.

While most people are better off buying a ready-made subwoofer box, there are a few people who prefer building one. If you want to build one continue reading, if not skip to the next section.

Tools Needed To Build A Subwoofer Box

  • A Jigsaw
  • A table saw or circular saw
  • An electric drill
  • Speaker terminals and cables
  • Your choice of material
  • Fasteners (screws, glues, and caulk)
  • Sonotube (for cylindrical subwoofers)
  • Varnish and paint

You must use the exact materials recommended to build a subwoofer box. Do not compromise on the quality of the tools and materials even if you are on a budget – buy the best quality materials. By using inferior quality materials, the build and design of your subwoofer will not be suitable for deep bass and you will end up with a lot of wasted time and money.

Benefits of Subwoofer Boxes

  • Optimal subwoofer performance

Even the best subwoofers would sound almost flat and somewhat distorted without a good subwoofer enclosure. Without an enclosure, the sound at the front of the speaker would collide with the sound radiation from the rear, which makes the speaker sound flat. A subwoofer box helps to prevent this sound cancellation, and the net result is a stronger bass.

  • Protect your subwoofer

A subwoofer enclosure helps to contain the speaker within a limited space, so it doesn’t move excessively when you play music at loud volumes. This helps to protect the speaker from physical damages such as rips or tears.

  • Prevent overheating

It’s normal for your speakers to get warm, but they may start to overheat when they are in an incorrect position. Housing them in a vented enclosure ensures that the speaker receives enough airflow to keep it cool, especially when playing music for an extended period.

  • Good aesthetics

Most manufacturers design subwoofers boxes with carpeted exteriors that match most vehicle interiors. The enclosed subwoofers make your car look classy, especially when placed in your trunk.

Key Features

Key Features

Enclosure Type

  • Sealed boxes are the best for small to medium vehicles with little space in the car.
  • It’s also more economical to go for a sealed box if you only have a single subwoofer speaker.
  • Consider going for a ported or a bandpass box if you are an audiophile who loves playing loud music during long car rides.


  • If you have a small or medium-sized car, then an 8- or 10-inch subwoofer box may be a perfect fit.
  • However, if you have the extra room in your vehicle, you can benefit from a larger, 12-or 15-inch subwoofer box as it can make the speaker louder.
  • Also having more space for air to move around the speaker can help to keep it cool.
  • Getting a dual or triple sub box is a great trick to save your money and still get more bass.


  • The material making up the subwoofer not only speaks to its durability but can also help to bring out a better-sounding bass.
  • The most common materials used to make subwoofer boxes are aluminum sheets, plywood, fiberglass, polycarbonate, and Medium Density Fiberboard (MDF).
  • Of the options available, MDF and plywood boxes are some of the best materials since they are usually thick, strong, and more affordable than the other options.
  • Fiberglass is also a solid choice since it’s strong, light, and has good weather resistance.

Other Considerations


  • The enclosure should complement the interior of your vehicle.
  • Most manufacturers make their enclosures with an outer carpeted layer or a slanted design that looks appealing when fitted into a car’s interior.

Available Space

  • Take all the necessary measurements to determine if you have enough room in your vehicle for a new subwoofer box.
  • The available space will also determine if you will go for a straight or wedge-shaped box.

Building a Subwoofer Box to Specifications

Building your sub box is the best way to get the right fit for your subwoofer cost-effectively. It’s straightforward, and it takes less than two hours to get the construction done. Plus, you have the creative freedom to design your subwoofer that’s on par with expensive ones.


Step 1. Determine the size of the speaker box

  • Reference the speaker’s template to find the speaker’s measurements.
  • The template is included with the rest of the basic speaker information upon purchase. If the template can’t be found, contact the manufacturer for the information or measure the speaker yourself.
  • Figure the depth (front-to-back dimension) of the speaker box by adding 2 inches (5 cm) to the depth of the speaker.
  • Use the speaker’s height and length measurements of the box’s internal height and length dimensions.
  • Multiply the depth, height, and length to determine the internal volume of the box.

Step 2. Make a Sketch with Final Measurements

  • Now that you have the final measurements, it’s time to sketch your subwoofer box using them.
  • Your box may appear rectangular or wedge-shaped.
  • However, you don’t need to fret if your box appears wedge-shaped, provided you used the right measurements.

Step 3. Cut Wood

  • Using a table saw, cut the MDF into pieces for the front, side, back, and top.
  • You could also use a circular saw for that, or better still, have the MDF cut for you for a small fee if you bought the wood at a large improvement store.

Step 4. Label Pieces

  • After cutting the wood, label each of the pieces using any marker provided in the package.
  • Then make a woofer cutout using a compass on one of the front wood pieces.

Step 5. Drill the Holes

  • Make a hole around the cutout edges on the board using a drill press or a handheld drill.
  • The hole must be large for the jigsaw to cut through.
  • Cut out the circle with the jigsaw, and you will have a large woofer opening.
  • You also need to make a rectangular hole at the box’s back panel to hold the terminal cup.
  • Rub a silicone caulk around the edges of the cup and screw it into the box.

Step 6. Attach Wood Pieces Together with Glue

  • First, join the front and back pieces and then add the top and bottom sides by fastening with 2-inch drywall screws.
  • Drill holes around the edges and drive screws into them.
  • MDF is susceptible to splitting, so you need to use carpenter glue to seal the wood.

Step 7. Smooth the Surface and Edges

After the glue and caulk have cured, smooth the surface and the edges with sandpaper if the woofer opening is a bit small, sand to enlarge the hole.

Step 8. Set up the speaker box

  • Hook up the speaker wires.
  • Cover the back, top, and bottom of the speaker box with 1 inch (2-1/2 cm) of polyfill to minimize resonance.
  • Insert the speaker and run the connectors through their appropriate holes.
  • Secure the speaker with screws through the mounting holes.
  • Caulk any openings to ensure the speaker box is airtight.
  • Allow the caulk to cure for 12 to 24 hours.

To Sum Up

As you can see, building a subwoofer box isn’t too difficult, providing you closely follow the specifications of your subwoofer. You can find this information from the manufacturer and use it to shape the design of your box.

Remember to take care of measuring and cutting your pieces and ensuring you follow our steps to create a subwoofer box that will deliver outstanding results.


Does subwoofer box size matter?
When it comes to subwoofers, the answer’s yes! The size matters greatly. A good rule of thumb is to add at least 2 to 3 inches to the size of the subwoofer. For example, a 10-inch sub should have a front panel at least 12 to 13 inches square. Size the depth of the box to create the volume you require for your box.
What kind of wood should I use for a subwoofer box?
MDF wood is ideal for making subwoofer enclosures. The wood is strong, durable, and thick enough to limit the distortion of sound waves. A close second is a plywood, which is lighter than MDF, but sturdy enough to create the best sound quality if laminated.
Can a subwoofer box be too big?
A bigger box will have less overall output but may have more output at lower frequencies due to its increased low-frequency extension. But, if you go too big, you’ll lose both overall output and low-frequency output (extension).
Does lower Hz mean more bass?
Generally, lower Hz means more bass. The frequency range means that as you go lower in the scale, the bass becomes deeper until you are at the range where you are mostly just feeling the bass and not hearing it. So, a low Hz rating on a speaker means it can reproduce the deepest bass in most tracks.
How to build a subwoofer box to specifications?
Subwoofer box is very popular among not only music enthusiasts but also among casual listeners as it enhances the quality of the audio and makes for a more long-lasting after-effect. And contrary to popular belief, it is very easy to make one yourself with cheap materials you can avail and those are capable of producing sounds of quality which is at par with that produced by some of the most expensive and premium subwoofers. But in reality, the main attraction of making your own subwoofer is the creative freedom you are getting to design a unique device reflecting your style.


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