Instructions for making a subwoofer enclosure with your own hands. How does a subwoofer box affect the sound? What should a subwoofer box be like?

Most car owners pay a lot of attention to the audio content of their car, install multifunctional head units that are in no way inferior in performance to modern computers, connect powerful sound amplifiers, and make special audio podiums to improve the sound quality of the speakers. An important role in a car's sound equipment is occupied by a subwoofer - a special low-frequency speaker that reproduces the bass components of a musical composition.

Regular car speakers can be installed in the standard sockets of the car, but the subwoofer needs a special box in which it will be installed. You can make such a case yourself, and if you take into account the size and shape of the trunk during design and manufacturing, the subwoofer will fit perfectly into the luggage compartment and will not take up much space.

Calculation of the required volume, type of housing

Making a cabinet for a woofer begins with determining the type of cabinet we need. The boxes are:

• with open body;
• with a closed body;
• with bass reflex;
• bandpass housing.

The type and volume of the case is quite easy to determine. To do this, you will need to know three speaker characteristics (the optimal speaker size for a car subwoofer is 12 inches), they are indicated on the subwoofer box or in the instructions, you can also find these characteristics on the manufacturer’s website:

• Fs – natural resonance frequency;
• Qts – total quality factor of the speaker;
• Vas is the equivalent volume of the speaker.

The housing type is determined by dividing the resonance frequency Fs by the speaker quality factor Qts:

• Fs/Qts>30 – open case;
• Fs/Qts>50 – closed housing;
• Fs/Qts>85 – bass reflex;
• Fs/Qts>105 – bandpass.

So, we have decided on the type of case, how to calculate the required dimensions based on the given volume Vas? It is best to calculate the subwoofer enclosure using special programs such as Perfect Box 4.5, Blaubox, VASCalc. Using such programs, you can calculate boxes of any geometric complexity. These programs are shareware, so no problems with the law. To ensure that the subwoofer fits well in the trunk and does not take up useful space, approach the measurement process with all seriousness; the future box should fit where you intended.

Housing materials

Subwoofer enclosures are made mainly from chipboard with a thickness of at least 16 mm, or plywood, preferably birch or shiplap. If the thickness of the material is not enough, you can fold 2 sheets together, fastening them with glue or self-tapping screws. Also during the manufacturing process you will need silicone sealant or wood glue, contacts for connecting the audio wire to the subwoofer and a round bass reflex, if the appropriate housing is selected.

You can buy a bass reflex in specialized stores or make it yourself from a piece of plastic pipe. To protect the wood from moisture and condensation, the body must be painted inside and outside with nitro enamel. The outside of the body is sheathed with carpet in the color of the trunk trim.

Stealth Corps

Well, if you don’t want to lose space in the trunk and bother with body calculations, you can make a stealth type box. This is a box hiddenly installed in one of the niches of the trunk, for example, on the side of the fender. This subwoofer enclosure is good for speakers 12 inches and below. The principle of making this case yourself is quite simple.

The niche for the subwoofer is cleared and completely covered with masking tape, preferably in a couple of layers. Cover with film or newspaper those parts of the casing and body that may accidentally get epoxy resin, otherwise it will be very difficult to remove it later. A thin layer of epoxy resin is applied on top of masking tape; after drying, the base of the stealth body is pasted over with epoxy resin with pieces (10*10 cm) of fiberglass over the entire surface. After applying the first layer of fiberglass and completely drying, the workpiece can be carefully removed from the trunk.

Fiberglass fabric is pasted over in 2-3 layers for strength and the required thickness. After drying, we try on the future body in the trunk niche and mark the cutting line of the edges with a marker. We cut off the excess with a grinder, and we are left with an almost finished housing for the subwoofer. We make a washer from chipboard or plywood into which the speaker will be attached. Please note that if the speaker is 12 inches, then the seat for it must be appropriate, try it on right away. We fasten the landing ring at the desired height inside the future housing using epoxy resin and stop rails.

We cover the top of the case with Lycra and coat it with epoxy, then we cover the top part of the case with fiberglass in 2-3 layers, without sealing the hole for the speaker. Particular attention should be paid to the junction of the upper and lower parts of the body; it is best to glue them inside and out. After drying, holes are cut for the bass reflex (if necessary) and for the subwoofer terminals. The body is covered with carpet, connected and installed in the trunk niche.

Advantages of a home-made case:

• The case will fit perfectly into the trunk, because all dimensions were taken into account individually during design.
• The efficiency of a homemade enclosure will be at the same level, if not higher, than that of standard models sold in stores, because your enclosure is designed for a specific speaker, and not just for the size of the seat.
• The stealth case will not take up space in the trunk and will provide high-quality sound.
• You choose the color of the upholstery yourself, and you can choose materials that perfectly match the interior.

The body of the bandapase is much more difficult to manufacture. The design includes several cameras and bass reflexes, but the sound quality with the correct calculations of such a box will be at the level of professional equipment. Although, if you try hard, even the most complex subwoofer enclosure can be made with your own hands.

When making a homemade cabinet subwoofer for a car, the question always arises: how to calculate the cabinet for the subwoofer? First, if the volume is unknown, you need to calculate the volume of the box for the subwoofer and then, already knowing it, calculate the box for the subwoofer.

Order the manufacture of the case!

Case size calculation

When the volume of the body is known, the shape of this body does not affect the sound.
There are various programs for calculating a box for a subwoofer (a program for calculating a subwoofer box is “JBL SpeakerShop” or “Winisd beta.”), but you can simply do the calculation, knowing yourself that the volume is V=h x L x A(where h is height, L is length, A is width).

For example, how to calculate a box for a subwoofer, if for a 12-inch subwoofer (305 mm), the recommended volume is 45 liters. The measured permissible height for the body in a car is 340 mm (h=340 mm), length 680 mm (L=680 mm), let's calculate the width. A=V/Lxh

The permissible height (h) for space in the car is h=340 mm=34 cm=0.34 m, and the permissible length L=680 mm=68 cm=0.68 m. 1 liter = 1 10−3 m³ 1 l = 0.001 m³ then V = 45 l = 0.045 m³.

Don't forget that there is an internal and external volume, so you need to take into account the thickness of the material from which the subwoofer box is made.
If the box is made of MDF with a thickness of 2 mm (0.02 m), then we reduce the measured values ​​of height and length by the thickness of the MDF on both sides and calculate the internal volume. h = 0.34m -0.02 x 2= 0.3m; L = 0.68m – 0.04m = 0.64m.

In addition, it is necessary to take into account when calculating the volume of internal struts used in the manufacture of the body. Suppose we use a beam with a thickness of 3 cm by 3 cm as spacers, then we get 4 bars with a length of 0.64 m (length L = 0.64 m) and 4 bars with a length of 0.24 m (the length obtained from the height “h” reduced by 3 cm on both sides 0.3 – 0.03 x 2 = 0.24). For now we will not take into account the internal struts on the sides. The volume that the spacers will have in this case is V=(0.03 x 0.03 x 0.64) x 4 +(0.03 x 0.03 x0.24) x4=0.003168 m³. Then we increase the volume of the box by the volume of the spacers. V= 0.048168 m³ A = V/L x h = 0.048168 m³ / 0.3 m x 0.64 = 0.2509 m.
If the volume is increased by the volume of the side struts, then A = 0.255 m.
We want to make a subwoofer enclosure with a slightly inclined front wall, in this case the lengths of the side walls will change: if A = 0.255 m, then A = a + b / 2 = 0.33 + 0.18 /2 = 0.255, that is, reduce the value length “b” by the amount by which you increase the value “a”.

for example, the subwoofer housing is installed in a wing niche, and will have a complex geometric shape, repeating the geometry of the niche, while the rear part of the subwoofer housing has different shapes. In this case, you will have to calculate the subwoofer housing in parts, counting volumes “1” and “2” separately » parts.

Making a box for a subwoofer with your own hands: step-by-step instructions

12-inch speaker for subwoofer Before you start designing and assembling the box, you need to decide on the choice of speaker. We recommend choosing 10-12 inch imported speakers, as they are most often used in car subwoofers and are best suited. We described in detail how to choose a speaker for a subwoofer in a previous article. The design of the box is also important: the quality and volume of low-frequency sound depends on it.

What types of subwoofer boxes are there?

There are several types of subwoofer boxes. The sound quality you get at the output directly depends on the design of the box. Below are the most popular types of subwoofers:

• Closed box- the easiest to manufacture and design, its name speaks for itself. The woofer is housed in a sealed wooden housing, which improves its acoustic performance. Making a subwoofer in a car with such a housing is quite simple, but it has the lowest efficiency.
• Bandpass 4th order is a type of subwoofer whose body is divided into chambers. The volumes of these chambers are different; in one of them there is a speaker, and in the second there is a bass reflex (air duct). One of the features of this type of subwoofer is the design's ability to limit the frequencies that the cone reproduces.
• Bandpass 6th order differs from the 4th order by the presence of another bass reflex and another camera. There are two types of 6th order bandpasses - the first has one bass reflex, and the second has two (one of them is common to both cameras). This type of box is the most difficult to design, but produces maximum efficiency.
• Bass reflex– a subwoofer with a special tube in the housing. It vents air and provides additional sound from the rear of the speaker. In terms of complexity in manufacturing and sound quality, this type is a cross between a closed box and a bandpass.

If you want to get the highest quality sound, you can opt for bandpasses. But this type of design has many details that must be carefully designed and calculated. All this can be done using a special program WinlSD, which will not only determine the optimal size and volume of the subwoofer, but also create a 3D model of it, and also calculate the dimensions of all parts.

Unfortunately, this program requires at least minimal knowledge in this area and the average car enthusiast is unlikely to be able to do everything right the first time. Moreover, in order for the program to work correctly, it needs some speaker parameters, which are also not known to everyone. If you do not plan to take part in car audio competitions, we advise you to discard the bandpasses.

A bass reflex will be the most optimal solution for a homemade subwoofer. This type of box is good because the tube (bass reflex) allows you to better reproduce the lowest frequencies. In fact, this is an additional sound source that contributes to the sound of the subwoofer and increases efficiency.

What materials do we need to assemble the subwoofer?

Multilayer plywood for the subwoofer box The material for making the subwoofer box must be strong, dense and well insulating sound. Multilayer plywood or chipboard is perfect for this. The main advantages of these materials are their affordable price and ease of processing. They are quite durable and provide good sound insulation. We will make a subwoofer from 30 mm thick multilayer plywood.

To make a subwoofer box we will need:

Wood screws (approximately 50-55 mm, 100 pieces)
Soundproofing material (Shumka)
Drill and screwdriver (or screwdriver)
Jigsaw
Liquid Nails
Sealant
PVA glue
Carpet, approximately 3 meters
Klemnik

Subwoofer box drawings

In this article we will make a box for a subwoofer with a 12-inch speaker. The recommended box volume for one 10-12 inch speaker is 40-50 liters. Calculating a box for a subwoofer is not difficult, here is an approximate diagram with the dimensions of the panels.
Scheme and drawing of the box
It is worth paying attention to the minimum distance from the walls of the case to the speaker. It, like the volume of the entire box, is calculated based on the inner surface.

Assembling a subwoofer box with your own hands

You can start assembling. We use a 12-inch Lanzar VW-124 speaker.
12 inch speaker for subwoofer
Its diameter is 30 cm, and the first thing you need to do is cut a hole for the speaker. The minimum distance from the center of the diffuser to the subwoofer wall is 20 cm. We measured 23 cm (20 cm + 3 cm plywood width) from the edge of the panel and cut a hole with a jigsaw. Next, we cut a hole for the bass reflex slot; in our example, it has a size of 35*5 cm.

Cut out the bass reflex slot and the hole for the speaker

Instead of a slot, you can use a classic air duct - a tube. Now we assemble the bass reflex slot and attach it to the front panel of the subwoofer. We go along the joints with liquid nails and tighten them with self-tapping screws.
Assembling the bass reflex slot panels
It is important to tighten the screws very tightly so as not to leave any voids. They will create resonant vibrations that will ruin the sound of the subwoofer.

Next, we assemble the side walls of the box, having previously lubricated them with liquid nails, and tighten them tightly with self-tapping screws.
Side walls of the box
On the back cover of the box you need to cut a small hole for the terminal block. We connect all parts of the body. We make sure that we cut and fastened all the parts correctly.
Assembly box
We insert the speaker. Let's look and admire.

Interior decoration

Let's move on to the interior decoration of the box. The first thing you need to do is seal all the joints and cracks with epoxy glue or sealant. Next, using PVA glue, we glue soundproofing material onto the entire inner surface of the box.
Cover the body with Shumka
Cover the body with Shumka
Now we cover the entire outer plane of the box with carpet, including the bass reflex slot. You can attach it with epoxy glue or using a furniture stapler.
The box is covered with carpet
Next, insert and screw the speaker tightly. The subwoofer is almost ready, all that remains is to stretch the wires from the speaker to the terminal block and connect the amplifier.
Installed subwoofer with amplifier
We bought an additional amplifier, but you can also make it yourself. This is quite difficult, as it requires knowledge and practice in the field of radio engineering. You can also use ready-made kits and circuits for radio amateurs, like Master-KIT, and assemble the amplifier yourself. The only requirement for the amplifier is that its maximum power must be less than the maximum power of the speaker.

Making a stealth subwoofer with your own hands

DIY stealth subwoofer Tired of carrying a huge box in the trunk? Then the stealth subwoofer is just made for you. This unique type of case is more practical than the classic box. It doesn't sit in a square box in the middle of the trunk and takes up less space. Often, stealth is installed in the inner part of the wing, sometimes in a niche instead of a spare wheel. The minimum volume of the box that requires a 10-12 inch speaker for normal operation is 18 liters.

To make a passive stealth subwoofer we will need:

subwoofer;
protective grille and socket for connection to the amplifier;
wire for connecting the speaker to the outlet;
multilayer plywood or chipboard (thickness 20 mm);
a small piece of fiberboard;
epoxy adhesive;
brush;
fiberglass;
mounting tape;
polyethylene film;
wood screws;
drill, jigsaw.

Choosing a location to install the housing

After choosing the place where the stealth will be installed, we empty the trunk and begin manufacturing the body. You can remove the trunk trim where the subwoofer will be installed to place it even closer to the fender. First of all, lay a plastic film on the floor of the trunk. It performs two functions at once: it protects the trunk lining from epoxy glue and allows us to make a mount to which we will screw the bottom of the subwoofer. Next, we cover the inside of the wing with mounting tape in two layers.
Cover the trunk with masking tape
We cut the fiberglass into small pieces, approximately 20x20 cm. We place pieces of fiberglass onto masking tape and glue them with epoxy glue. It is better to overlap the fiberglass fabric so that there are no obvious joints and seams.
Epoxy glue + glass mat
We sculpt layers of fiberglass on top of each other, simultaneously lubricating them with epoxy glue, until the thickness of the sheet reaches 10 mm (about 4-5 layers).
Panel thickness approximately 1 cm
The material will harden in approximately 12 hours. To speed up the process, you can use a lamp. Now we cut out the bottom of the subwoofer and glue it to our body. The joint is treated with sealant or glued with epoxy resin.
Glue the bottom
In this particular case, the shape needs to be adjusted to the trunk hinges so that our homemade subwoofer does not interfere with its closing. After we cut off all the excess, we cut out the side walls and the top cover from chipboard. We make the rounded part from plywood, we did it “by eye”.

Making the side, top and bottom walls of the box

To make it easier to give the plywood a rounded shape, you must first wet it, give it the desired shape, secure it and let it dry.

Chipboard sheets must be glued with epoxy glue or sealant, and then fastened with self-tapping screws. We also glue the fiberglass box using epoxy resin, and when it dries, we fasten it with self-tapping screws.
Glue and fasten the parts
For better sealing, you can glue the seams again. We applied another layer of epoxy glue and pressed the structure with sand to help the glue adhere better.
Sandbags for better traction
Next we can measure the front panel and cut it out. Using a jigsaw, cut out a circle for the speaker. In order to securely attach the front panel to the body, you need to tighten it with self-tapping screws on all sides. That is, you need to install bars on the entire inside of the panel, at a distance slightly greater than the thickness of the plywood (in our case, we attached the bars at a distance of approximately 25 mm from the edge of the panel). Thanks to this, we will be able to secure the front part at the top, bottom, sides, and most importantly, securely attach it to the rounded element.
Preparing the front panel
Cut a hole in the end for the socket.
Cutting a hole for the terminal block
In the end, it was decided to add two more layers of fiberglass and epoxy glue to the curved part of the body for the stealth subwoofer.

We carry out the final assembly: install the socket and connect the speaker to it, but do not screw it yet. Then there are two options - paint the subwoofer, or cover it with carpet. Painting is a little more difficult, since you must first level the surface. For this we used universal putty.

There are quite a lot of interesting ways to do it. And sometimes a homemade subwoofer even turns out much better than a purchased one, if, of course, you do everything right.

What can a subwoofer be made from?

Something like a subwoofer can be built from several pieces of plywood and old speakers. And in general, as for the subwoofer speaker, you can buy it, for example, on the radio market.

You can also enjoy clear audio in a car by using an inactive subwoofer. In addition, making it yourself will not be difficult. It will not require the installation of an amplifier, and the work will be reduced only to design and assembly. As for the installation of such a subwoofer, it is installed directly inside the box.

Video on how to draw a subwoofer enclosure:

We begin production

The first thing to do is arm yourself with the necessary materials and tools. To make a homemade subwoofer we will need:

• speaker;
• protective grille;
• good glue, preferably epoxy;
• socket through which the connection will be made;
• fiberglass;
• wire, 3 mm;
• brush;
• plywood;
• Chipboard, 16 mm;
• nuts and screws, always for wood;
• bolts;
• masking tape;
• polyethylene;
• universal putty.

And of course, the tools - where would we be without them:

• jigsaw for wood;
• screwdriver or drill.

Begin. First you need to choose a good speaker. Needless to say, the more powerful it is, the louder the sound will be. How to get it? It is worth noting that the speaker can get into your hands in different ways. The main thing is to have data on its technical indicators. After all, the design of the body will depend on them, and this is very important.

So. As for the indicators, you must first obtain data on the resonance frequency of the speaker you happen to have in open space. In addition, it is also necessary to find out the data on the equivalent volume. If there is no such data, then it is better to go and buy a speaker in a store, where they will provide it with special documents. You can choose the most modest or expensive speaker. Here everything will depend only on you.

Now the second stage, called designing the subwoofer box. You can use a special computer program WinlSD 0.44. This utility will really help. It is she who will require you to enter the speaker data and its parameters. And this type of computer program allows you to make four types of boxes. We will consider the box that has the highest efficiency. In other words, a level 6 bandpass.

The sixth level bandpass is a rectangular cubic object, inside of which there is one jumper. It is on this that our speaker will be fixed. In addition, such a bandpass has two holes that are intended for mounting bass reflex cameras. Instead of cameras, various tubes can be used. For example, these could be tubes made of polyethylene, metal or just paper. It is worth noting that the housing must be completely sealed and this can be done using felt, foam rubber or ordinary cotton wool.

As for the sealant layer, it should have two centimeters inside. And the roof of the subwoofer must be removable and have a high density at the junction. Therefore, it is also additionally reinforced with a layer of foam rubber.

The computer utility will help all sizes. She will calculate the optimal numbers for the case, of course, based on the capabilities of the speaker. In this case, the person’s task becomes only to clearly and competently translate everything into reality. And the sound, of course, will meet all expectations. It will turn out clean and loud.

It is believed that in general, assembling a subwoofer is a difficult task if you are not extremely attentive to various small details and nuances. A person assembling a homemade subwoofer must not only understand acoustics, but also have the ability to be a woodcarver, be able to screw in self-tapping screws and bolts, and also work with sealant. For the home craftsman, this is a unique challenge.

Subwoofer space

Now about where we will install our subwoofer. We choose a place for it. The best option would be to install it in the wing: right or left, we decide for ourselves. Although, it is worth noting that there will be more space in the right wing, due to the configuration of many cars.

If we chose a medium speaker, then it will need at least 28 liters of volume for normal operation. As for the configuration and volume of the box itself, you will have to experiment here. Usually the volume turns out to be large, but this is not scary.

We cover the trunk with plastic film, and then cover the trim with masking tape, always in two layers. We take fiberglass and cut it into pieces. In this case, they should turn out to be 200x200. Be sure to lubricate them with epoxy glue and overlap them with tape.

Now about how to dilute epoxy glue. The correct thing to do would be to mix a can of resin and a can of hardener. If you take more of these substances than normal, the glue will quickly thicken and you will not have time to use it. The ideal ratio is 1:1.

We cover the back wall of a homemade subwoofer, or subwoofer, with three or even four layers of fiberglass. Then we wait until everything dries. It's better to wait a day.

The next day you will need to remove the resulting shell. We are already increasing its thickness outside the trunk. We begin to glue the bottom of the subwoofer. We make its top in the shape of loops, and fasten the front wall with self-tapping screws. As for the joints, they will need to be coated with epoxy glue.

Fine work

After the body of the homemade subwoofer is ready, you need to prepare it for the acoustic terminal, that is, the speaker. To do this, you need to mark a hole on one of its side walls. This can be done with an ordinary school compass.

Powerful ones are obtained if it is shielded with a small box. This is no longer the basics of homemade subwoofer construction, but real art. Thus, we will be able to eliminate various overtones that arise due to the rather flimsy acoustic terminal.

The box may have a square shape. We treat it with PVA glue and screw it to the side panel where the hole was cut using self-tapping screws.

Now you need to take a plane and cut off all the protruding edges of the body with it. When it was said above about special skills, this was done for a reason. And here you need to have the skill of a carpenter to cope with the job with an A plus.

Go ahead. We take a jigsaw, preferably an electric one, to make it easier to work, and cut a hole in the front panel. It will be needed for the speaker, which is attached there with self-tapping screws and glue. If the reader remembers, there is a jumper inside our box, or sixth-level bandpass. This is where you will need to cut.

Protective measures

Everything seems to be ready, and the amateur will immediately rush to connect. But the master has no need to rush; every step in his work is an opportunity for him to touch sublime art. So, in this case, you should not forget about protecting your homemade creation from moisture and condensation. Even medieval people knew that moisture on wood, and in this case thin chipboard, has a destructive effect.

In order to secure and protect the case in advance, you need to impregnate it with a special furniture nitro varnish. It is advisable to carry out this procedure in the fresh air to avoid varnish poisoning.

Don’t forget to saturate the inner end of the front panel as well.

Video demonstrating how to make a subwoofer yourself:

Well, that seems to be it. It's time to study the subwoofer circuits and connect them. Although for a more spectacular finish it is useful to cover our subwoofer with some material for beauty. If you have carpet, then it can become that very material.

A subwoofer is a separately installed speaker system that is designed to reproduce low-frequency sound waves in the range of 20-120 Hz. It only sounds at low frequencies when the main speaker system only at high and mid frequencies. Low-frequency sound is unrecognizable to the human ear, so it can be mounted anywhere in the car interior. Making your own subwoofer is not a difficult task. You need to start by purchasing speakers.

Types of subwoofers

There are passive and active subwoofers.

Passive subwoofer It is a housing with a speaker built into it. For a subwoofer of this type to operate correctly, an external amplifier with sufficient power is required.

It comes with its own low-frequency amplifier already built into it with the ability to adjust the volume. Many active subwoofers also have bass and treble cut controls. This is necessary so that the sound from the subwoofer is consistent with the speaker system. The most significant drawback of this type of subwoofer is its high price.

Interesting to know! In 1998, Russian craftsmen from the Autolux company created the Bluesmobile from a Nissan Terrano II. It was equipped with four amplifiers, six speakers and nine subwoofers, with a total sound pressure of 147 dB. This monster holds an official record of 135.9 dB. But this is quite enough to feel how your internal organs “walk” throughout the body.

Choosing speakers for a subwoofer

Typically, subwoofers use speakers of the following sizes:

Six-inch speakers, used as additional sources of mid-bass frequencies.

Eight-inch speakers, used to produce front bass.

perfectly reveal their potential in a closed case with a volume of 15-20 liters. This results in a good subwoofer of compact size with optimal sound pressure.

Twelve-inch speakers are optimal for housings from 25 to 35 liters. This is perhaps the most optimal option.

Fifteen inch speakers often used in SPL sound pressure competitions. They are built only into housings from 60 to 90 liters, and such a device will not fit into every car.

The basis of the resistance difference in the sound coil operates on the principle: the lower the load resistance the amplifier has, the higher its power. A load of 1-2 ohms leads to deterioration in sound quality. It is recommended to choose twice the load of 2-4 ohms.

Neither experts nor amateurs have yet agreed on the power characteristics of the speakers. But what can be confirmed with certainty is the need to choose a speaker that is superior in power to the amplifier. No audio system is designed for long-term operation at peak power. This leads to an increase in nonlinear distortions and a significant decrease in the quality of reproduced audio signals. Therefore, some balance must be maintained.

Selecting speaker parameters

Now it's time to create a virtual model of a homemade subwoofer. It is better to design the future box using the WinISD 0.44 program, but this will require some characteristics of the speaker, or rather the Thiel-Small parameters:

Qts- speaker quality factor;

Fs- resonant frequency in open space;

Vas- equivalent volume.

You won't have any problems with the Fs parameter. For GDN35 Fs will be 38 Hz, for GDN50 - 40 Hz, and for GDN75 it will be 25-35 Hz. If the speaker is branded and made abroad, then its parameters can easily be found in the WinISD 0.44 database.

When calculating the subwoofer box enclosure, the most important parameter is Qts. This parameter determines the ratio of the transfer function of the frequency dynamics Fs to the transfer function at those frequencies whose frequency response is horizontal. To put it another way, at frequencies above Fs, Qts determines the efficiency of the speaker at the resonant frequency. The only problem is that low-frequency speakers, for example, of the HDN standard, are produced in different places, and the parameters vary greatly between different manufacturers.

When calculating a box for a subwoofer, it is necessary to take into account all possible variations in Qts values ​​and add waste options. Many sources indicate the following parameters:

35GDN-1-8 Qts = 0.4;

35GDN-1-4 Qts = 1±0.5;

50GDN-42D Qts = 1±0.5;

75GDN-1-4 Qts = 0.2-0.5.

Vas- is not a particularly important parameter that affects the calculations. It can be considered equal to the following:

GDN35 - 40-50 l.;

GDN50 - 90 l.;

GDN75 - 80 l.

Designing a Subwoofer Box Using Software

The next stage of making a subwoofer with your own hands is to choose the type of box. Using the program, you can create projects of four types of boxes:

closed box;

Bass reflex;

4th order bandpass;

6th order bandpass.

Each speaker has its own positive and negative sides. The choice of box, to a large extent, should be made based on the selected speaker itself. The program will help you figure out which box will suit the speaker best.

Before creating a subwoofer box project, you need to model the speaker with the parameters stored in the database. Click "New", then select "Own drivers", then "New" again, and load your parameters. Then confirm – “OK” and close – “Close”. Then create a project based on this speaker. Repeat the procedure several times using different types of boxes.

Design consists of varying the size of the boxes and adjusting the frequency of the bass reflexes. The program reacts to the changes you make and changes the sound graph in real time depending on the frequency. To adjust the frequency of the bass reflex, the length of the pipes and their diameter are changed. Make sure that the size of the pipes does not turn out to be too large; this will be indicated by the Vent mach field, which will light up in red. The ideal graph is the one that crosses the -3 dB line at a frequency of 25-35 Hz, and then passes along the 0 dB line and drops to 150-200 Hz. Further design will involve searching for possible deviations.

Types of box design

There are four most popular types of subwoofer boxes. The design features of the boxes directly affect the quality of the sound obtained at the output. Below we will briefly talk about them:

is the easiest option to model and manufacture. In fact, its name expresses its essence. The subwoofer speaker is placed in a closed wooden housing, which improves its acoustic characteristics. It won’t be difficult to make such a case, but its efficiency is the lowest of all those presented.

It is a body divided into chambers of different volumes. A speaker is placed in one of them, and an air duct in the other. The peculiarity of this subwoofer design is the ability to limit the frequencies reproduced by the diffuser.

Bandpass 6th order differs from the previous one only in that it has one more additional air duct. This type of design is the most difficult to design and create, but has the highest level of efficiency.

– a housing with a tube built into it that removes air. Due to this tube, additional sound comes from the rear of the subwoofer. In terms of the quality of sound characteristics and the complexity of manufacturing, this type can be placed between “ZY” and “Bandpass”.

Subwoofer housing drawings

For example, let's look at the diagram. In this article we will make a box for a subwoofer with a 12-inch speaker. The volume of the structure for it should be 40-50 liters. Designing a housing for a subwoofer is not difficult. Here is a rough diagram for this. Just pay attention to the minimum distance from the speaker to the walls of the box. It, like the entire volume of the structure, is calculated on the inner surface.

Material selection and required tools

Necessary materials to create a subwoofer enclosure:

Speakers, when choosing which, you need to know the difference in their characteristics. Usually the instructions or on the box indicate the recommended design specifically for a given speaker.

Plywood sheet, fiberboard, chipboard. The quantity must be calculated based on the size of the future building.

Acoustic terminal. Optional element. You can simply drill a couple of holes through which to bring the wires out of the speaker.

Acoustic cable.

Sealant or PVA.

Self-tapping screws for wood.

Epoxy resin.

Varnish or paint.

Glue for carpet. The one in the can is convenient.

A bass reflex enclosure requires a tunnel of a suitable size. If you do not find what you need on sale, then purchase a pipe of the required material at a building materials store. Plastic, cardboard and even metal will do.

Necessary tools to create a subwoofer enclosure:

Jigsaw.

A screwdriver, if not, a screwdriver.

Roulette.

Pencil or marker.

Carpet or other material for the outer covering of the body.

Scissors.

Case manufacturing stages

1. Cut the walls of the housing according to its dimensions. It is necessary to cut, observing the dimensions, carefully measuring. When assembling, the gaps should be minimal; ideally, the parts of the body should fit as tightly as possible to each other.

2. Coat the joints of the walls with sealant and connect them together. Then secure them with self-tapping screws in increments of five centimeters.

3. Re-coat the joints both outside and inside. Do not allow even the slightest holes, as a whistle will be heard through them when the subwoofer is operating.

4. Cut a hole for the speaker terminal in a convenient location.

5. Use a jigsaw to cut out a hole for the speaker.

6. If the box is designed for a bass reflex subwoofer, then the corresponding port is installed in the corresponding hole using epoxy resin.

7. To protect the case from moisture, it must be coated with varnish or paint.

8. Cover the case with carpet or other material, leaving holes for the speaker, port and terminal.

9. Place the terminal in its place and secure it with self-tapping screws, additionally coat it with epoxy.

10. Secure the wires inside the terminal to the terminals. Connect the other side of the wire to the terminals on the speaker. The wires should not sag. The length should be sufficient for connection.

11. Reinstall the speaker. Seal the joint between the speaker and the box with a gasket. If this did not come with the speaker, you can use foam rubber or window sealing.

12. Secure the speaker to the body with the self-tapping screws that came with it or any other suitable ones.

Now let's talk in more detail about how to make a subwoofer yourself and mount it on a car. The most convenient and universal body shape is a slightly truncated pyramid. Since most cars have a standard rear seat angle of 23 degrees, the rear wall of the subwoofer is inclined at the same angle. After determining the required space, calculate the size of the case and draw a drawing of the body of the future wooden case.

It is better to make the front wall from chipboard with a thickness of 23 mm, the side wall - 20 mm. Cut out the walls from the material according to the dimensions in the drawing, and then assemble the body. It is better to lubricate all connections with glue and secure with self-tapping screws. It is better to drill the holes for them to 3 mm, and for the heads it is better to take a drill with a diameter of 1 cm. Next, on the side, use a compass to make markings for the future acoustic terminal. Cut them out with a jigsaw. A terminal under high pressure may make unnecessary sounds. To avoid this, shield it with a small box, then coat the joints with glue and secure with self-tapping screws. Use a plane to cut off any excess projections.

In the front, mark and cut a hole for the speaker in the same way. To protect against moisture, impregnate the body with nitro varnish. It can also be applied to the inner end of the front panel. For greater attractiveness and practicality, the exterior of the body can be covered with carpet. It sticks to the same nitro varnish. Connect the speaker to the speaker terminal and attach them to the housing.

Housings for this type of subwoofer are quite bulky. Such a subwoofer is difficult to calculate and configure, but such a homemade element of a car speaker system has a higher efficiency than the previous version. In this case, the parameters are also calculated using special software. The assembly of the body is carried out as in the previous version, only it must also be carefully sanded. Next, cut out holes for the bass reflex, handle pockets and socket. Install all fasteners and check them thoroughly. The body can be covered with leather.

The manufacture of a housing for this type of subwoofer should be undertaken by those who have experience in making calculations, because it is difficult to calculate and it is easy to make mistakes in dimensions. But the bandpass produces a wonderful sound and has good efficiency. In addition, it is well protected from external mechanical damage, as it is completely hidden in the housing. Calculations are also carried out using computer software, but not only for the entire body, but also for each of the cameras separately. When you cut out the parts, stick to all the dimensions as closely as possible.

The design is assembled as in previous versions. The partition with the speaker is made from two sheets of chipboard. The inside of the body is covered with noise-absorbing material, batting, for example. The glue is applied in small strokes over the entire area. Do not pour a lot of glue to avoid static properties. You can additionally secure the structure with a construction stapler. Solder the wires to the terminal and speaker. The rear camera must be completely sealed. The greatest tightness is achieved thanks to liquid nails and tape glued over the seam.

The bass reflex bell is made by heating the edges with a can and expanding them. A carpet with a bass reflex is placed in the hole cut with a jigsaw in the lid. Coat the joints with liquid nails. The rear cover with the bass reflex is covered with noise-absorbing material. Assemble the finished subwoofer and cover it with carpet.

Bandpass 6th order

This is the most difficult subwoofer to assemble and calculate. You shouldn’t even approach this without thorough preparation. Comparable to the previous version, but produces a much larger frequency range. Its efficiency and power are difficult to calculate even with the help of simulation programs. As a rule, all parameters are selected solely according to personal preferences.

The design of the body is much more complicated than in previous versions. To make the connections much stronger, they are made from wooden blocks secured with self-tapping screws. Cut all parts strictly according to the calculated dimensions. Everything is done further using a technology similar to the fourth bandpass, only use cotton wool as an additional soundproofing material.

Homemade stealth subwoofer

This type of subwoofer is hidden as much as possible and takes up almost no space in the trunk, so it is very convenient to use in a car. It is usually installed in the trunk behind the rear arch. A good speaker requires a housing of 18 liters, and sometimes more. The housing can be moved slightly inside the trunk, and the subwoofer can also be placed in a niche intended for a spare tire.

When installing a stealth subwoofer, you need to extend its front panel slightly and connect it to the luggage compartment upholstery. It is necessary to construct a form from corrugated cardboard, gluing its pieces together with masking tape. Assemble the amplifier frame and try on the equipment. Next, make a fiberglass cladding panel for the amplifiers that are already installed on the frame.

Seal all spaces between the plastic with tape and polyethylene. Then everything is screwed with self-tapping screws to the housing box. Corrugated cardboard is used as formwork to eliminate gaps in the body. To give a more attractive appearance, you need to use fiberglass and putty. Install the subwoofer into the rear fender and smooth out any uneven surfaces with sandpaper. Cover the body with carpet and attach the speaker.

Subwoofer backlight

To illuminate the subwoofer, you can use both LEDs and diode strip. LEDs have two contacts: anode (A) and cathode (K). To properly connect the LEDs, you need to connect pin A to the positive side of the power supply, and K to the negative side. The resistors of each individual LED are soldered to the Anode. Decide in advance how you will mount the LEDs inside the subwoofer. It is better to place them so that they stick together and tightly. The equalizer sensor must be located away from the subwoofer so that it is not damaged.

If you use an LED strip as backlight, then fixing the diodes is replaced by installing the strip. This will make installation easier for you, since they are already carefully adjusted to each other and well secured. It is quite simple to mount the tape inside the subwoofer using double-sided tape. Using this option, you can vary various design solutions. For example, a ring of LEDs around the speaker, the brightness and color of which can be adjusted as you wish.

Every car owner who tunes his car is guided, for the most part, only by his preferences, taste and imagination. What experts advise is generally accepted as recommendations. The same can be said about how to create subwoofers yourself and then install them.

How to assemble a subwoofer box

How to assemble a box for a subwoofer so that the speaker in it plays with all its power?
This question is of interest to many admirers of good sound who want to improve the audio system of their car. In our article we will learn how to assemble a box for a subwoofer, exactly the way it should be.
To begin with, before starting manufacturing, it is recommended to determine the type of speaker that reproduces low frequencies. As a rule, experts recommend choosing speakers with 10-12 inches. They are the ones that are popular today and are most often used as subwoofers.

Subwoofer boxes and their types

Today it is customary to distinguish between several types of subwoofer boxes (see). As you know, the quality of the sound obtained at the output directly depends on the type of box and its design.
So:

• The box is a closed type, the most common type in manufacturing and design. In such a box, the woofer will “feel” good. Its acoustic characteristics will improve significantly. In addition, such a box will be much easier to build yourself.

• Bandpass box. It is also called a fourth-order box. This design implies the presence of divided chambers inside. Typically, these same cameras come in different sizes. In one chamber there is a speaker (see), and in the other there is a bass reflex or air vent.

Note. The advantage of this type of box is its special design, which is capable of limiting frequencies.

• 6th order bandpass box. It is noticeably different from the one described above, in particular in that it has two more cameras inside.

Note. There are two types of level 6 bandpasses. Bandpass with one bass reflex and bandpass with two bass reflexes. The latter is the most difficult to design, but is capable of delivering excellent efficiency.

• Bass reflex box. It has a special tube inside.
  It removes air, providing additional sound. As for the complexity of manufacturing such a structure, it is something between a bandpass and a closed box.

A music lover will immediately say that it is better to opt for a bandpass. But this design will be a little complicated for a person who has taken up homemade production for the first time.
There are many parts in a bandpass type box, the creation of which involves design and careful calculation. If you have time and desire, then you can choose them.

Note. Nowadays, computers can be trusted to calculate and design dimensions and designs. The special WinLSD program will help you find the right size, estimate the volume of the subwoofer, calculate the dimensions of parts, etc.

On the other hand, the program described above is certainly not for a knowledgeable person and will require highly specialized knowledge. And why so much pain if you can start making a simpler box of good quality. This is a bass reflex device capable of reproducing the lowest frequencies.

Making a bass reflex box

So, we’ve decided on the choice of box and it’s time to move on to the manufacturing process.

Materials

First of all, we will need materials. As a rule, this should be a component that is a durable material that perfectly insulates sound. Multilayer plywood is best suited for these purposes.

Note. As a last resort, if it is impossible to find plywood, chipboard will do.

Also, will prepare this:

• Self-tapping screws in the amount of 100 pieces, preferably 50-55 mm.
• Some kind of soundproofing material.
• Liquid nails or silicone.
• PVA glue.
• Sealant.
• A piece of carpet 3 meters long.

Tools

As for tools, the following accessories are suitable:

• A screwdriver or drill as a last resort.
• Terminal block.
• An electric saw and preferably the same plane.

Process algorithm

So, we make a bass-reflex box for a 12-inch speaker. In this case, it is recommended to make the volume of the box equal to 40-50 liters.

Below is the calculation table:

Note. It is very important to pay careful attention to the length that runs from the cabinet wall to the speaker. This parameter is calculated, like the cavity of the entire box, based on the surfaces inside.

So:

• We make a hole for the speaker and for the bass reflex slot.

Note. To make all the holes, we use an electric jigsaw, which is very convenient to work with.

• Assembling the bass reflex slot.
• We attach it to the subwoofers (see) - to the front panel.
• It is advisable to go over all joints with silicone, or better yet, with liquid nails. After this, tighten the screws.

Note. It is highly recommended to tighten the screws tightly so as not to leave any voids. Leaving them on may affect the sound quality. Resonant vibrations will occur, interfering with normal sound.