A subwoofer is an element of an acoustic system that reproduces the sound of audio tracks at the lowest frequencies. Having a good subwoofer is a music lover’s dream, because everyone loves high-quality sound of music inside the car. However, such a device is not cheap. However, most car owners can calculate the subwoofer box and make it themselves in order to avoid unnecessary expenses on a factory model.
How to choose speakers for your subwoofer
Subwoofers are used in cars to improve the sound of music at low frequencies. For regular listening to melodies or radio broadcasts, the standard audio system in the car is quite sufficient, but connoisseurs of loud and clear sound at low frequencies prefer to place a subwoofer in the cabin.
When selecting speakers for a future product, the car owner learns that they can be round or oval in shape and size. Typically (based on the dimensions of the car interior), round speakers with a diameter of 10, 13 or 16 cm, as well as oval ones with a length of 15x23 cm are selected. Accordingly, the larger the diameter of the speaker, the better the sound will be reproduced at low frequencies.
How to Know Which Car Speakers Are Right for You
Before making a subwoofer for your car yourself, you need to clarify several basic points:
- The shape of the speakers does not affect the sound quality of music in the car;
- The depth and richness of the sound is affected only by the size of the speaker;
- You need to think carefully about the exact shape and size of the speakers so that the subwoofer looks appropriate in the cabin.
Design is not of paramount importance, so when choosing a speaker, its technical characteristics are a priority
Designing a homemade subwoofer
Car subwoofers are installed in the luggage compartment or on the rear parcel shelf, which is why this system is called rear.
The most important point in manufacturing is determining its size and design. Depending on the tasks assigned, the design can have a variety of variations.
Types of subwoofers
There are only two main types of subwoofers. If we talk about the relationship to an audio power amplifier, then they are conventionally divided into:
- active. They already have a built-in amplifier and crossover, which provide high sound quality and remove high frequencies from the sound. An active subwoofer receives signals from any source with which it has a connection;
- passive. The device is not equipped with additional amplification elements, so it is connected to the main audio system of the cabin. The only drawback of a passive subwoofer is that it seriously loads all the channels of the system, and therefore the sound quality decreases.
Active subwoofers do not load the standard cabin audio system, so they have better sound quality
Where to install: in the trunk or under the seat
If an active subwoofer can be placed almost anywhere, then the purity and power of its sound at low frequencies will directly depend on the location of the passive device. Depending on the preferences of the car owner and the availability of free space in different types of cars, several installation locations are offered:
- in the center in front is the optimal position for communication with the front speakers, which will ensure almost ideal sound of tracks in the cabin. However, most cars don't have room in the front to accommodate any large devices, so a center front location is more suitable for minibuses;
- in the trunk, with the speaker directed forward - one of the most popular ways to place a subwoofer among drivers. Suitable for all types of vehicles;
- in the trunk, with the speaker directed backwards - more suitable for a car in a hatchback body, since the sound wave does not encounter obstacles in its path. The location in the trunk back is unacceptable for cars in a sedan or coupe, since the sound will be greatly deformed due to the specific design of the luggage compartment;
- on the floor under the seat is another option, which, however, is not widely popular among drivers. Due to the fact that the subwoofer is located flush with the floor, and the housing is located under the seat, the sound encounters many obstacles in its path;
- on the rear parcel shelf is one of the best options for placing a subwoofer in all types of cars. The main condition is that the shelf must be wide and strong enough to withstand low-frequency bass.
Photo gallery: main places to place the device in a car
The program algorithm will take into account all your wishes and calculate the volume and other parameters of the case quickly and correctly
What to make a box from
A subwoofer box is more than just a box that houses a speaker. The box must comply with many dynamic laws of acoustics in order for the sound to be truly rich and clear. To make different types of boxes, different materials will be required, and the manufacturing methods will in many ways be different from one another.
How to build a box for a bass reflex subwoofer
The standard version of a homemade subwoofer is a bass reflex. This is the simplest type of subwoofer; moreover, its box is good because a special bass reflex tube allows you to reproduce low frequencies that are practically not perceived by the human ear. And the design of the box is quite simple, which makes its production accessible to almost everyone.
Required tools:
- sound insulation;
- wood screws 50 mm long;
- drill;
- screwdriver;
- electric jigsaw;
- liquid Nails;
- sealant;
- PVA glue;
- carpet
The housing for housing a bass reflex subwoofer must be as durable as possible and not allow sound waves to pass through. Multilayer plywood or high quality chipboard is perfect for these purposes. The best option is to take a plywood sheet 30 mm thick.
To make the case you need to follow this plan:
- Prepare parts of the body: front, back, two sides, bottom and top in accordance with your calculations or parameters derived by programs.
- To fit the speaker size (for example, diameter 160 mm), cut a hole in the front part of the housing blank.
- Above the hole for the speaker you will also need to cut a slot for the bass reflex tube and screw the bass reflex compartment to it.
- After two holes are made on the front panel, you need to glue all the side parts of the box together and then screw them to each other with self-tapping screws.
- In this case, it is especially important to tighten each screw until it stops, since empty spaces between the panels will seriously distort the sound of the speaker.
- Next, you will need to cut a small hole for the wires on the back of the case.
- Before connecting all parts of the case, we insert the speaker.
- Next, it is necessary to carry out the interior finishing of the case: for this, all joints and cracks need to be coated with resin or sealant to improve the sealing, after which soundproofing fabric is glued to all side panels.
- After completing the interior decoration, you need to move on to the exterior: the body is covered with carapet fabric, and the fabric should also cover the slot for the bass reflex. Karapet can be tensioned using regular epoxy or a furniture stapler.
Once the speaker is secured, wires are pulled from it through the hole and connected to the car's sound system.
Photo gallery: how to assemble a compact box with a bass reflex
You can connect the subwoofer yourself, based on the parameters of this circuit
Before starting work, make sure that the vehicle battery is disconnected. This is a safety measure that will not only avoid damage to the speaker system, but can also preserve the health and performance of parts of the human body.
Video: connecting and setting up a subwoofer
Independent design, manufacture and connection of subwoofers in a car is available to almost every driver. The key to success will be both a competent calculation of the dimensions and volume of the product, and careful assembly of the case. At the same time, the car enthusiast can independently select the desired size of speakers in order to create in the cabin the low-frequency sound that suits him most.
A subwoofer is an important part of any complete speaker system. In some cases, you can assemble a low-frequency speaker with your own hands. In this case, you need to take into account a number of important characteristics of the subwoofer in order for the speaker to sound as it should.
One of the main parameters of a low-frequency speaker is the size of the cabinet. It is very easy to decide on the material from which the box will be made - you should use a dense and hard material that absorbs sound well - for example, medium-density pressed wood. With sizes, everything is not so simple. To calculate the correct linear parameters of the box, special programs are used that you need to learn how to use.
Before you begin calculating the body, you should decide on the type of box. He can be:
- open - with a bass reflex - a cylindrical hole in one of the walls, which allows the sound to be better focused;
- closed - with solid walls and a sealed body.
Obviously, the quality of a low-frequency speaker directly depends on the diameter of the dynamic driver - the larger it is, the better. Therefore, by definition, a speaker cannot be small if you want to achieve the highest quality sound. In addition, the shape of the body must be strictly defined - cubic or rectangular. Having mastered these basic principles, you can begin to calculate sizes.
Calculation of a closed subwoofer enclosure
If the right speaker has already been selected and all that remains is to place it in a suitable housing, the task becomes quite simple. Calculating a box for a low-frequency speaker using a special program is not a difficult task if you understand its interface. We can say that it will be much more difficult to decorate this box beautifully. As a result of the calculation, the result should be a box with such a volume that the sound from the speaker built into it has the most linear amplitude-frequency response in a particular room or inside a car.
To calculate the hull, you will need to use one of the programs designed for this; There are a huge number of them, and in principle, any one will do. A good option is JBL SpeakerShop, it is free and has a simple interface that even an inexperienced user can easily understand. The only problem is that the program is entirely in English, which may be a barrier for some people. However, you don’t need any special knowledge - the main thing is to press the right buttons.
In order to correctly configure the program to calculate the required box, you need to find the instructions or data sheet included with the subwoofer. In it you need to find the Thiel-Small parameters:
- Fs – resonant frequency of the emitter, measured in hertz;
- Vas – effective volume of the body, calculated in liters;
- Qts is the quality factor of the speaker, which is a set of physical forces that arise near the emitter during its operation and are associated with its mobility.
You can also find other parameters in the data sheet of the speaker - if they are known, you can enter them into the program, but this is not at all necessary. For a fairly accurate calculation of the box, the three above indicators are sufficient.
Calculation process
The calculation is made as follows:
- Net volume is the volume of the body that is not occupied by anything. It does not include the space occupied by the bass reflex port and the emitter body, as well as the sound-absorbing material with which the walls of the box are lined from the inside.
- Setting up the port - selecting the size of the bass reflex so that at a certain frequency (in the case of a subwoofer, low) the sound is amplified and receives a linear frequency response.
Calculation of the net volume of the housing
You will have to act in exactly the same way as in the case of a closed box. Open the program for calculation, enter the indicators Fs, Vas and Qts in the appropriate fields. We build the calculated frequency response, which we then change by adjusting the calculated volume of the subwoofer housing.
Several liters should be added to the resulting volume to account for the volume that will be occupied by the speaker housing and the bass reflex port. Everything is clear with the speaker, but how do you know how much space the bass reflex will take up?
Calculation of the bass reflex port
The bass reflex port will also be calculated using a special program - BassPort. This program is intended specifically for a subwoofer, since low frequencies require a bass reflex with certain parameters.
Using the program is easy:
- enter the bass reflex frequency;
- indicate the net volume of the box;
- the effective area of the emitter membrane, to calculate which you will need to know the diameter of the speaker;
- the peak amplitude of vibration of the diffuser, it can be found in the instructions for the speaker;
- At the bottom of the main window, select the tube shape;
- indicate the dimensions of the bass reflex;
- after clicking on the “calculate” button, the program will display the missing parameters of the port: its length, the volume that needs to be added to the net volume of the box, the wind speed in the tube, etc.
Subwoofer box calculation: video
Subwoofer housing calculation
Calculating a housing for a subwoofer is not easy for every motorist, even one who is very passionate about music and understands various acoustic subtleties. A subwoofer is a complex and independent acoustic system designed to create high-quality sound inside a car.
However, few motorists know how to design a subwoofer housing correctly and without problems.
Hull and its calculations
So, directly the algorithm for calculating the subwoofer housing:
- There are four main types of subwoofer enclosures available today;
- Housing 3Ya is a closed type structure. This type, from the point of view of design and manufacturing, is the simplest. However, it has practically no efficiency. On top of that, it is leaky;
- The phase inverter (PI) has a complex calculation principle, but it has a high efficiency;
- The 4th and 6th order bandpass is the most difficult option from the point of view of design and practical manufacturing, but it has the highest efficiency within the range of low sound frequencies and at the same time completely suppresses high frequencies.
Note. Objectively, each of the options described above has a number of characteristic advantages and disadvantages, however, the choice must be made in accordance with the recommendations of the design program.
Program WinlSD 0.44
Before moving directly to the design process, you need to create an audio speaker in the database using the WinlSD 0.44 program:
- First, you need to move the computer mouse cursor to the New tab, after which you need to check Owndrivers and click on New again. After that, download the parameters selected in accordance with your own wishes and capabilities. At the end, just click OK, Close;
- Then you need to create a project based on the speaker and previously specified dimensions;
- Next, you need to repeat the above procedure many times, changing the type of case, having tried all four variations.
Direct algorithm for creating the housing itself for a car subwoofer
Here's what you need to know:
- The most optimal shape would be a truncated pyramid, since it is the most universal;
- The slope of the rear wall should be approximately 23 degrees, since the vast majority of modern passenger cars have an interior with the rear seat backs tilted at exactly this angle;
- It is imperative to calculate the volume of the case in accordance with the dimensions of the free space of the trunk (see).
Creating a closed enclosure
Begin:
- All walls of the 3Ya case (closed type case) must be made of chipboard, and the front wall must be 23 mm thick, and the side wall must be 220 mm thick;
- Now you just need to cut out the walls of the specified size from chipboard with an accuracy of a millimeter, and then you can proceed to the direct assembly of the body;
- The connection should be made using glue and specialized screws with their further screwing in at a distance of 5 cm from each other;
- For the self-tapping screws, you need to create holes exactly 3 mm in size using drills, and for the heads of the self-tapping screws, you will need to create the corresponding recesses using a 10 mm drill;
- Now it's time to mark the holes for the acoustic terminal using a simple compass;
- Next you need to create the corresponding holes using an electronic jigsaw.
Note. If the acoustic terminal is constantly under high pressure conditions, then various kinds of overtones will regularly emanate from it. In order to avoid the effect described above, it is necessary to simply shield the acoustic terminal using a small box.
Let's continue:
- Before proceeding to screwing the pre-prepared screws, it is necessary to coat the entire surface of the joints with glue;
- The parts of the body that protrude after gluing just need to be carefully cut off using a plane;
- In a similar way, it is necessary to mark and cut the corresponding holes already on the front wall in order to ensure high-quality installation of the car speaker;
- Nitrolacquer for furniture must be applied to a wooden body in order to preserve the properties of anti-moisture and anti-condensation processes;
- To create a beautiful appearance, it is recommended to cover the outer part of the body with carpet (see);
- Now all that remains is to simply connect the acoustic terminal and the subwoofer speaker.
Note. It is extremely important to familiarize yourself with all stages of the instructions and understand the design program, as this will allow you to perform independent installation and individually design the box directly to the dimensions and capabilities of the luggage compartment of your car. Also, during absolutely all stages of work, a high degree of attentiveness and accuracy is important, because any inaccuracy will certainly affect the final result.
Self-construction instructions in combination with photo and video materials will allow you to complete the work quickly and efficiently. The price of the issue is minimal and is ten times different from the operation performed in the workshop.
It is quite possible to build a housing with your own hands. The main thing, we repeat, when creating and constructing for the first time, is to carefully read the detailed practical instructions.
A car subwoofer is a low-frequency speaker that is installed inside a special housing. A self-made subwoofer is designed to reproduce sound at low frequencies. Our article will tell you how to make it. You will also find out what options for subwoofer boxes exist. The enclosure is an acoustic design that isolates the sound waves emitted by the back and front sides of the speaker cone, since when they cross, self-damping occurs, which is called a short circuit.
Types of box designs
There are several popular options for car subwoofers:
Do-it-yourself subwoofer: what to make the body from?
What material is best for creating a subwoofer enclosure? Let's look at a few popular options:
- Chipboard is the most suitable option, which is inexpensive and easy to process. You should choose a material of maximum density with a thickness of at least 16 mm. Chipboard absorbs moisture well and swells, so it is better to paint it.
- Fiberboard. As in the case of chipboard, you need to choose a material with maximum density. It flakes easily, especially if it gets wet. You need to work with fiberboard carefully, otherwise you can ruin everything. Regardless of all the disadvantages, the material is very comfortable and makes it easy and quick to assemble a housing for a subwoofer with a medium-power speaker.
- Plywood. It is better to choose plywood from Russian birch or ship's wood. Many other varieties do not have a high enough density, which causes distortion in the sound.
If you have sheets of fiberboard, chipboard or plywood, but have a small thickness, to ensure the required structural rigidity, fold two sheets together, coat them with sealant, wood glue or PVA, and twist them with self-tapping screws.
Tools and materials
Materials
The materials you will need are the following:
- Speakers. When choosing them, you should know that different models have certain characteristics. The instructions or on the box always indicate the recommended acoustic design for a particular speaker.
- Fiberboard, plywood or chipboard. The quantity depends on the dimensions of the case.
- Wire terminals.
- Acoustic cable.
- Epoxy resin.
- PVA glue or silicone sealant.
- Varnish or paint.
- Self-tapping screws for wood.
- Carpet
- Glue in a can for carpet.
- If you are making a bass reflex enclosure, you will need a suitable tunnel. If you don’t find the right size tube on sale, pick up a plastic pipe of a suitable diameter at a hardware store.
Tools
- Screwdriver or screwdriver.
- Jigsaw or hacksaw.
- Long ruler or tape measure.
- Pencil.
- Scissors.
Before assembling the subwoofer box, you need to calculate it correctly. Download a program on the Internet called JBL SpeakerShop or its equivalent, and calculate the dimensions of the case. You will figure out how to do this - there is nothing complicated about it.
Subwoofer manufacturing stages
First, you need to cut the walls of the future box to size. Cut carefully to size to ensure minimal gaps during assembly.
Group the walls by sealing the joints with sealant, and then screw in self-tapping screws every few centimeters.
Re-coat the joints with sealant inside and outside. If even a small hole remains, you will hear an unpleasant whistle through it when the speaker is operating.
Cut a hole in a convenient place for the terminals for the wires - the so-called acoustic terminal.
If you are making a bass reflex box, secure the bass reflex port in the appropriate hole using epoxy resin.
To protect the case made of chipboard or fiberboard from moisture, coat the material with varnish or paint, preferably nitro.
Tighten the case with a carpet, not forgetting to leave holes for the terminal and speakers. Install the acoustic terminal in the designated place and secure it with self-tapping screws. We recommend coating the seat with epoxy resin from the inside.
Connect the two wires to the terminals inside the terminal. Connect the other ends of the wires to the speaker terminals - they should have the length needed to comfortably connect the speaker.
Insert the speaker into place, and place the seal in the joint between the plane of the box and the speaker. If this was not included in the kit, use a window seal or a foam strip.
Secure the speaker with the screws included in the kit or with simple wood screws. So, the work of assembling a subwoofer for a car is completed, and all you have to do is connect the device to the amplifier.
