Subwoofer structure diagram. Self-made subwoofer. Subwoofers are classified into two types

A subwoofer, also known as a "bass speaker", is a separate acoustic element that reproduces sound frequencies in the range of 20 ... 120 Hz. Figuratively speaking, within the framework of the entire layout acoustic scheme, the subwoofer occupies the range low frequencies, while the entire speaker system reproduces mids and high frequencies.
Subwoofers are divided into active and passive, the former have a power supply unit with an amplifier in the case, while the latter are connected to the amplifier from the outside.

We make a subwoofer

This manual has been written specifically for those who dream of having a 5 1 with a subwoofer installed in their car, but for one reason or another they cannot afford to purchase a subwoofer. It is not at all difficult to make an acoustic subwoofer yourself, and due to the fact that the human ear does not recognize the direction of low-frequency waves, you can install a subwoofer in a car in any accessible place.

Tools

In order for your thought to materialize in the image of a subwoofer, in addition to wild desire and "obstinacy" we need a couple of little things:

Hacksaw for wood;
Chisel;
A set of files (triangular, round, flat ... whatever else is there ...);
Sandpaper of various sizes (grain size);
Screwdriver, or a set of screwdrivers
Electric drill;
Jigsaw, preferably with a "non-manual drive";
A set of stationery, where the compass has a "span" not less than the diameter of the selected speaker (20 ... 25 centimeters);
Wood glue;
Building material for the body (plywood, chipboard, MDF with a thickness of 10 ... 20 millimeters);
Wooden blocks (for stiffening ribs) with a section of 20x20 ... 40x40 millimeters;
A bunch of self-tapping screws (from 10 to 50 millimeters);
A program for calculating the parameters of a subwoofer (JBLSpeakerShop, WinISD 0.44, etc.).

So, we begin the creation of a low-frequency speaker with the choice of a speaker (see).

Speaker selection

Since you are not the first music lover on this earth, we must assume that some well-established canons in the world of music already exist, the same applies to the use of speakers:

Six-inch is used as an additional source of mid-bass;
Eight inches are responsible for the front bass;
High-quality acoustics on a car is obtained with ten inch speakers installed in a 15 ... 20 liter case;
The best option is considered to be a twelve-inch speaker in a 25..35 liter case;
Well, a fifteen-inch housed in a 60..90 liter case, as a rule, is in the hands of true "maniacs" and is put on display to the respectable public during the SPL competition.

By the way, both among amateurs and among professionals, there is still no agreement on the power of the speaker. But on this moment it can definitely be argued that the speaker should definitely be more powerful than the amplifier, since no system is able for a long time, for maximum volume reproduce sound signal without the appearance of nonlinear distortion and a significant decrease in sound quality, everything should be balanced here.
We select the speaker that suits us, of course, the more powerful it is, the louder the sound will be. It doesn't matter how you got it, how it got to you, we need to know its technical characteristics, because a very important stage depends on them - the design of the case.

Calculation of parameters

If you do not have accompanying documentation with the technical data of the speaker, and there is no way to find out these parameters from the manufacturer, then we will have to calculate them with our own hands.
We will have to find out data about:

Speaker rated power (usually given in the head marking - 75GDN-1 75 W) - Pnom;
Resonance natural frequency - Fs;
Natural resonance frequency in a closed space - Fc;
Equivalent speaker volume - Vas;
The greatest displacement of the diffuser - Xmax
Effective diffuser diameter - D;

Well, about the readings of the Q-factor of the resonant frequencies:

Complete - Qts
Electric - Qes;
Mechanical - Qms.

To get the required parameters, we need:

Digital multimeter (voltmeter);
Calculator;
Any low-frequency generator, for example GZ - 109 (instead of it, you can use the low frequency generator program on a computer, since there are a great many of them in the network);
20 liter, hermetically sealed box.

So to sound card, through the linear output we connect the "amp", and from its outputs, through a resistor with a nominal value of 1 KOM, the speaker is connected (see photo):

In order to avoid the influence of third-party objects on the quality of measurements, we suspend the speaker in the middle of the room on a chandelier. Next, we launch the LFO "program", set the frequency to 1000 Hz and set the middle position of the volume control on the computer;
To avoid signal distortion, connect the multimeter to the "amp" output and, by adjusting the volume on it, set the voltage to 20 Volts;

We connect the multimeter to the speaker;
We increase the generator frequency (starting from a frequency of 5 ... 10 Hz), follow the voltmeter data until the desired speaker frequency at the maximum voltage (Umax) reaches its maximum, after which it begins to decrease. The readings of the generator, at which Umax reached its maximum on the voltmeter, are recorded as data Fs;
We gradually increase the frequency relative to Fs until the readings stop changing. We write down the value of Umin (a further increase in the frequency, of course, will cause an increase in the amplitude, but these data are no longer important to us);

We can already express the obtained data in the form of a graph of the amplitude-frequency characteristic of the speaker:

When viewing the graph, you can observe the new input Uav, F1 and F2, these are the frequencies with which we will determine the quality factor of the speaker using the formulas Qes, Qts, Qms and Uav.
Previously, calculations were done manually, but now everything is extremely simple - download the TSCalc "prog", insert the known values and get the result:

Rmax value = Umax * 1000;
Re value = the value of the resistance of the speaker with direct current;
Substituting these values into the program, we get Rx;
Uav = Rx / 1000
F1 we are looking for decreasing the frequency downward relative to Fs until the voltmeter shows the value of Uav;
We search for F2 in the same way, only we raise the frequency up;
Substituting the obtained values of F1, F2 and Fs, we obtain the required data for the Q-factor of the resonant frequencies.
Next, we need to find the resonant frequency of the speaker in a closed space - Fc. To do this, we fix the speaker with a magnet outward (not fundamentally, it's just more convenient) in a pre-prepared box, and we look for the desired one in the same way as the value of Fs.
Substituting the values of the already known volume of the box, as well as the found data Fc and Fs, we obtain the values of the equivalent volume - Vas;
The effective diameter and the maximum displacement of the diffuser are found using a ruler.

Box selection

Now that we know all the necessary parameters, we can start choosing the type of subwoofer enclosure.

Attention! No matter how I would like to upset you, but only the parameters obtained (and not your desires) are the main factors determining the type of case. This does not mean that you will not be able to assemble the type of case you have chosen, but whether it will produce the sound we need is a question ...

Free air

This type of speaker is suitable when Fs> 100 Hz. As you might guess, a travel subwoofer will not work out of it, since it has almost no sub-low frequency range.
The maximum where it can be determined is the rear of the car, but the best option would be to search for another speaker.

Closed Box

We choose this type if the Qts value is less than 0.8-1.0 (optimally 0.7), and Fs / Qts is 50. It is not at all difficult to calculate it.

Vented Box (bass reflex)

It is optimal when Qts is less than 0.6 (optimal indicator is 0.39), and Fs / Qts is 85. More difficult to design.

Band Pass (band approach)

It has the highest efficiency, and at the same time is the most difficult to manufacture. Optimal when Fs / Qts is 105.

PassiveRadiator (passive radiator)

The same bass reflex, only a membrane radiator is installed in place of the pipe. The calculation of its parameters is similar to that of a phase inverter, but it is a little more difficult to manufacture.
Although if you take an old speaker, dismantle a magnet, a diffuser and a basket from its case, glue a plexiglass plate (getinax, etc.) to the rubber cage, and screw a load (a bolt with a nut) into its center, with which Fc can be adjusted, then you will get a very good and not expensive PassiveRadiator.
Any of the presented options can be made with one or two speakers. So, we know the parameters, we have decided on the type of case, it's time to start calculating the case.

Calculation of the box

In this case, I decided to use the JBLSpeakerShop program.

Do not expect details from me, this "program" is very simple and straightforward (by the way, on the Internet video instructions are always at your service).
But I will still tell you the procedure:

Download the program and run it through the "setup.exe" file located in the first disk, after which we indicate the path to the second part of the installation file;
Launch the program and go to the "Loadspeaker" menu where we enter the head parameters;

Select the type of box and go to "Box - Parameters", where, on the selected option, enter the frequency and volume of the desired resonance (when entering these parameters, you can improvise and watch the result on the graphs);
Further, after the parameters are selected, if there is a phase inverter in your subwoofer, we activate the "Vent" key and enter the pipe parameters;
In the "Dimensions" submenu, select the shape and size of the box;

In the "Grafs" menu, select the displayed chart;
We print the result - "Ctrl + P".

Making a subwoofer box

Preparation

As you know - practice, this is the criterion of truth, well, since the calculation is over, we proceed to the most interesting part of our instruction, where one rule reigns - measure seven times, cut one.

Advice! When choosing a case material, it is necessary to take into account that the greater the speaker power, the thicker its wall should be, and the stiffer the mounts.

So:

We take a prepared sheet of high-quality (not dry and not old) plywood, which is an order of magnitude stronger than chipboard, and draw all sides of the box on it.

It is not worth saving at this stage - then there will be nothing to correct the mistakes.

If you have a hacksaw with a "hand drive", it is better to choose with small teeth and with a guide. To avoid delamination and cracking, cut slowly, at an angle, the above is also true when working with an electric jigsaw.
We use a file to process all protruding pieces of plywood and compare the humps and depressions resulting from sawing off.
We measure out the blocks and saw them off to size, for which purpose we will “estimate” the body from the sawn parts and take measurements.

One of the crucial moments is considered to be making a hole for the speaker.
Since a drill with a diameter of 150 ... 300 millimeters is somehow problematic to find, we will think with our heads:

We measure the diffuser with a rubber cage and, taking a slightly higher value, measure the circumference on the plywood with a compass. Next, we retreat from this line inward by the value of the radius of the selected drill (adding a couple more millimeters), mark a circle of smaller diameter.

Method one

We drill a line of a small circle with a 10 ... 15 mm drill, insert a jigsaw file into the resulting hole and cut out a hole, holding the file in a large circle.

Advice! Before drilling, place the plywood on a hard surface - this way, the drill will not "touch" the back wall at the exit.

Method two

It is not necessary to draw the second circle - we drill a hole anywhere inside the circle, insert the jigsaw file and smoothly bring it to the line of the drawn circle.

Method three

Along the entire diameter of the small circle, we drill holes close to each other, after which we punch the jumpers between them and process the circle with a file.

Estimate the speaker by the hole, and if everything suits you, drill holes for mounting nuts, which can be purchased in any department of furniture accessories.

Advice! The connectors used in concert acoustics are very practical and reliable and are best used.

Assembling the box

So, the holes for the speaker and bass reflex are made, the bars are sawn, we proceed to the assembly work:

We take a drill with a diameter two times smaller than the diameter of the self-tapping screw and drill through the plywood sheets in those places where they will dock with the bars and with other walls;
Before joining the parts with a thick layer, we coat the contact points of the walls and the bars. In our case, a thick layer of glue performs two functions simultaneously - it increases the strength of the structure and seals the joints;

Advice! Screw on the back panel at the last assembly step.

We install the speaker, while the junction of the diffuser and the plywood is coated with an automotive, water-repellent sealant (good sealing of the seam +, if necessary, can be easily removed);
From scrap materials of a round shape (except for metal pipes, pieces of water supply and sewerage), we make a phase inverter by entering the diameter of the pipe into the program and obtaining the value of its length. It's not worth fixing it tightly yet, we still have to configure it.

By the way, the phase inverter can be square in shape, in this case, in the process of its manufacture, you will have to fantasize a little:

Any sound-absorbing material can be used as a damping material, for example, a thick layer of nap, felt, cotton wool, hard foam rubber, etc.

At the time of setting, install in place back cover boxes;
We connect the unit through an amplifier to a low-frequency generator, and a voltmeter to the speaker contacts;
By changing the frequency of the generator, using the above-described method, we find the value of Fc;
If the desired value differs from the calculated one, then by changing the parameters of the phase inverter and the amount of damping material inside the subwoofer box, experimentally we find exactly the moment when the resonant frequency will completely suit us.
In the case when the calculated length of the phase inverter pipe exceeds the length of the subwoofer itself, its diameter should be changed;
We finish assembly work, fixing all the remaining parts "tightly".

This completes the instructions for making a car subwoofer with your own hands. You just have to check your work in practice.
We turn on the hardest version of the musical composition at full volume and listen to the playback for the appearance of extraneous noise, rustle, whistle:

A whistle indicates a gap left inside an uncovered space, the hole which should be covered with a sealant, putty or glue;
Rustling means that a moving speaker damper is in contact with its cone.

We finish external processing subwoofer: we round off sharp corners, sand it, cover the pits and cracks with putty or mastic, then glue it over with material and install decorative grilles on the speaker diffuser and phase inverter pipe.
That's all. I hope you will be pleased not only by the price of your "brainchild", but also by the excellent sound quality.
After all, if you did everything right, then without your prompting, hardly anyone will guess that the powerful and clear bass coming from the interior of your car is reproduced from a homemade subwoofer. What, by the way, is not a shame to brag)))

For a long time I thought about making a "boozer" for cinema in the form of an active sub to the LFE channel.
As a LF 30GD-2 (LF from the S90), since these are available and are lying around in large quantities (well, they cost a penny in the right places, so it's not a pity). Well, I'm a rogue :), I'm sorry for a decent sub for more than 15,000 rubles. give away. According to the calculations, I decided to choose the 6A bandpass. Only it gives a very decent return and a low cutoff frequency. According to the calculated frequency response level -3db - 24 -63 Hz. The assembled sub looks like this.

The quality of the photos is mostly terrible, as I took pictures with my phone (well, I had neither a soap dish nor a DSLR at that time).
Who cares, welcome to cat. There are a lot of ph.

Design

The general design is very similar to the well-known design on the internet.
This is an example of the appearance from one site (I will not indicate the authorship of the picture, since I do not remember where I took the photo, if anyone knows write in a personal message, I will put a link). Naturally, the dimensions will be completely different.

To manufacture a structure, it is necessary to know or obtain the parameters of a specific speaker. They are called Thiel-Small parameters. If you do not know what it is, then Google and wiki will help you, everything is measured quite simply, software and methods are googled with a bang. Not all software is free, but I will say that you can measure with an accurate voltmeter, accurate scales, clay, generator and amplifier. Googled on "add mass method". I used the method of additional mass, but I automated the measurements with the appropriate software (I do not indicate the name since the software is paid, but we are in Russia, who needs that will find everything;)).
It makes no sense to give the measured parameters, because each speaker is unique and assembling the structure according to "foreign parameters" will not lead to anything good. How to say about the dynamics of the times of the USSR, so as not to be rude ...
I have 4 woofers and they all have completely different parameters, although they are of the same brand.
For those who want to point out and "cheer" that "high-quality" sound cannot be obtained from bandpass, I will repeat once again the sub was going to watch films and to sound the LFE channel, in which there are mainly effects.

Calculations

Here are the design drawings of the case and the calculated frequency response, everything is designed for a specific speaker.
The calculations are the same in 4 programs I know.
I took as the main calculation program Bass box pro

Calculations for losses of useful volume of the case

"Saw, Shura, Saw"

After all the calculations, I ordered a chipboard cut in one company that deals with furniture, everything was very cheap
Here is the middle baffle for mounting the speaker.

Side walls

in the background you can see the drilling tool, oh, and I hesitated to drill.

Side panel with bars for reinforcement and fastening.

We are trying to put everything together into a single structure.

Let's try a bass reflex from a sewer pipe

We will cover the walls with a sound absorber

And so with the speaker

Electronic filling

The preamplifier was assembled according to the scheme www.electroclub.info/samodel/sub_pred.htm
I drew the signet myself under the smd resistors and reduced it in size. If someone is interested in it, I can post it in Sprint Layout format.
As the final amplifier I chose an amplifier based on TDA7294 with an adjustable output impedance.
Scheme and description. The signet was used from the author. In order not to climb far, the diagram from the original source:

I will not describe in detail the process of making seals, I will only give the finished result. Made by LUT (Laser Iron Technology). As material for transfer - cut sheets of the PC Week magazine.
Preamplifier board ready for etching and after ferric chloride etching.

Power amplifier board based on TDA7294

I collected almost completely the ULF, a pair of ohmic resistances and one oxidizer were not enough, and I assembled a pre-amplifier with a subsonic filter and a low-pass filter with a variable frequency crossover and a phase switch. There is also a Linkwitz corrector on the board, but it is not wired, since it is not needed to design a bandpass. On the pictures the boards are not washed from the flux, that's why they are so "beautiful".

End amplifier

Preamplifier

Set assemble subwoofer

We take a piece of aluminum, mark it out and make back panel amplifier block

Do not forget about the fusible link, as a radiator, something from the stock from AMD

Power amplifier board

Made all connections

Feeding from some old trance, again wound by ourselves. In ancient times, a transformer stood in some kind of tube TV until it fell into my hands and was rewound for some kind of amplifier, it was a long time ago). Power supply to the terminal + - 35 V.

Since this view is somewhat not pretty, we paint everything with black matte paint from a spray can

We put fake sweaters

True subwoofer must be spiked. The spikes were ordered by the turner's father. These are the results

Let's take

And fix them

We make the sub reasonably beautiful and cute

For starters, I'll give you a photo of the intermediate result. It can be seen from them that such a sub will not decorate the apartment. Well, nothing will fix it.

Without cover

He took out a vibrating grinder, putty the holes from the screws, leveled the case and began to glue it with self-adhesive under a light wood. First I bought a self-adhesive for pasting in one layer. Initially, the idea was a light body and matte black details. After the first layer, it became clear that one layer is very small.
First layer

I tried to cover the bottom with varnish, it became clearly visible that one layer was just shining through.

I had to go to the store again for the film. The second layer was more fun to stick, as my wife helped. It is much easier to glue in four hands.

After two layers, the film began to be varnished. I don't remember the brand of varnish now, I remember that it was quick-drying and seemed to be diluted with acetone. It cost about 50 rubles per can because it was overdue :), but we do not care, we are rogue.
Two layers of varnish

After drying, it looks like this

Closer

How much does it cost?

600 r - sawed me parts on the case + material + delivery to the house.
100 r - screws.
120 r - timber
250 r - phasic pipes + a connector for connection in the end turned out to be superfluous and there are a lot of pipes, 50 r would be enough.
50 r - sealant (expired)
50 r - sculptural plasticine
200 r - 2 pcs TDA7294 (I burned one out of stupidity by confusing the polarity)
200 r various small parts of which were not available.
120 RUR variable resistors with handles
50 r varnish (expired)
200 r 5 meters of self-adhesive
100 rub skin
85 r black matte paint
70 r sewer pipe

Total 2160 r., I don't seem to have forgotten anything

Free - brought a cardboard tube for the phazik
free - woofer
free - tool

A little calculation and reflection

The design pressure is about 109 dB in the operating range, with a power input of 50 W. For a long time I thought I could lie. Haste calculations

70 watts the pressure is, as you can see, there is a slope, since the din actually works below the resonant frequency, but according to the schedule it does not go beyond the permissible stroke even by 20 Hz

100 W the situation is the same

I looked for the sake of interest, what can be pumped into din and 200 W and there will be no stroke limitation at 20 Hz. You can make the pipe blow up to 18 Hz. But there is a natural question whether such power is needed? According to my impressions, when there was no separate amplifier, I rocked it with an industrial amplifier of 25 watts, if done at full, it is very, very loud. I turn it on in full only when I want to show someone all the power, to boast. That is to say, to amuse ChSV :) But in this mode you will not listen for a long time, everything that can be shaken and rattled by the glass is powerful in one word.

PS The constructions have been made for a year already, I have been doing it for my mood for 3 months, for my own pleasure.
Was it worth it or not? I think yes. The bass is very low and deep. Due to the design, the sub plays very softly, it cannot play a sharp attack, and it doesn’t need it, but all the LFE effects are going with a bang, everyone listening was delighted. Despite the fact that the sub is on spikes, the walls, floor and glass still vibrate noticeably, creating an effect no worse than in cinemas (to remove the bounce of glass).
Recently we presented a dynamic head from an autosab, I will make another one, but this time a closed case and with a Linkwitz corrector.

A true music lover does not like listening to music through standard computer speakers. A good speaker system is chosen based on personal preference. Such pleasure is not cheap, in addition, sometimes difficulties arise with the selection of the columns of the required parameters. In this case, you can make a speaker system with your own hands. In our article, we will look at how to make a subwoofer from a regular speaker.

Subwoofer (subwoofer) is formed from two words - SUB and WOOFER, which is the literal translation of "subwoofer" and means - an acoustic system capable of reproducing sounds at low frequencies, for example, from 20 to 100 Hz. Many users prefer to call it “bass speaker”.

Subwoofers are classified into two types:

Active subwoofer - the speaker housing contains an amplifier and a power supply.
Passive subwoofer - it does not have an external amplifier.

Speaker selection In order to select a speaker, you need to decide on the dimensions. The following models are present on the modern market:

Speakers with a 6-inch subwoofer typically serve additional source middle bass. The use of such speakers in terms of sound depth creates a rather modest device that is suitable for a small salon with an average speaker system.
Speakers using an 8 ”subwoofer are used for additional front bass.
The ideal speakers for a car subwoofer are speakers 10 inches or more. They really sound quality and fill the space with powerful and pleasant sound vibration. The speakers are placed in a closed compact case or a so-called “closed box”, which is able to provide good sound pressure. The best option for a car is a 12-inch speaker, which can be used in a box with a volume of up to 35 liters.
15-inch speakers are a viable option for larger car interiors. In this case, the box for a speaker with a given diameter should be about 90 liters and take up the entire luggage compartment. In addition, with such a dynamics, you can become slightly deaf, so this option is not very practical.

Important! It is necessary to decide on the resistance, since a load of 1-2 ohms will greatly spoil the sound. The optimum impedance for a subwoofer speaker is 2 to 4 ohms.

Speaker power is definitely a tricky decision to make. There is only one rule, which is that the speaker power must be greater than the amplifier power. No speaker can last long at its maximum power, so it must have a “safety margin”.

Important! Users are not always satisfied with the sound that comes from a home theater. This problem is easily solved with additional columns.

If you already have both a speaker and an amplifier, then you need to determine this difference and mark the maximum acceptable volume for the subwoofer. No speaker can maintain sound quality at maximum volume.

Important! After a while (sometimes this situation can happen right away), the disturbed balance will start to cut the ears terribly.

How to make a subwoofer for your computer?

Self-production of a subwoofer is carried out in several stages:

selection of materials;
hull design;
assembly of the subwoofer.

Selection of materials

How to make a subwoofer at home? Starting all work, you should choose necessary materials for the manufacture of the case. In order to make a subwoofer with your own hands, you need to purchase in advance:

speaker - selected based on your needs;
Plugs - Facilitate the connection of the speaker to the turntable, they should perfectly match the connectors on your device;
wires - used to connect a subwoofer;
plywood with a multi-layer base;
trimming plumbing pipes;
self-tapping screws for wood, which can be from the smallest up to a size of 50 mm in length; wooden bars with a different section, which can be from 20x20 mm and more;
silicone sealant; hard foam rubber or felt;
PVA glue;
dye.

Having prepared the necessary materials, you should also collect the required tool:

a hacksaw for wood, which would have small teeth;
chisel;
electric drill;
file;
jigsaw;
compass;
simple pencil;
iron ruler;
screwdriver;
screwdriver;
sandpaper - from rough to "zero".

Designing the enclosure We are starting to design the enclosure of the future subwoofer. For this we use a computer and a speaker, which serves as the “heart” of the subwoofer.

Important! In this case, it is very important to have the data of all technical characteristics dynamics. These include full Q, open-space resonance frequency, and equivalent volume. All these values are present in the passport data.

We load a special program on the computer device. We bring in software all speaker data. Based on the provided values, the program will calculate the optimal dimensions for the subwoofer box for you.

Important! WinISD 0.44 can design 4 kinds of subwoofer. The most optimal box that is able to work with maximum efficiency is the bandpass. The speaker of such a device is attached to a jumper inside the box. This subwoofer is equipped with two cameras and two bass reflexes. To make a bass reflex, you can use plumbing pipe cuttings. The program is able to calculate the length on its own, but you must specify the value of the diameter.

Now let's proceed directly to the design of the subwoofer box itself. All actions should be carried out slowly, since the slightest inaccuracy in measurements can cause inconvenience, and all work will have to be started anew.

Collecting the subwoofer

Before you start assembling the subwoofer, you need to cut out the box. How to make a subwoofer for your home with your own hands:

Using a ruler and a pencil, draw the outlines of the future box on a sheet of plywood.
We cut out a plywood sheet using a hacksaw or jigsaw with a speed controller.

Important! Sawing should be done slowly, without haste, because in a rush, the plywood can peel, which will negatively affect the sound quality of the subwoofer in the future.

In order for all edges to be perfectly smooth and even, we clean them with special care with a file and sandpaper. We attach the subwoofer walls to each other with bars, so you need to set aside the required length of the bars.
Cut a hole under the speaker. The speaker will be located inside the subwoofer.
In the jumper between the chambers, draw a circle with a compass, which has a diameter slightly larger than the speaker cone.
The edges should be perfectly flat and smooth, for this we clean them with a file and sandpaper.

Important! When filing, it should be kept at a slight angle to avoid delamination of the plywood.

The subwoofer walls will be attached with the bars, so we measure the corresponding length of the bars.

Important! The program indicates the places where the two holes should be cut - they serve for the bass reflexes.

We solder the wires and necessary connectors to the speaker. The wire attachment points can be found in the speaker manual itself.
We apply a speaker to the resulting hole. We make a mark for attaching the speaker to the sheet, we drill.

Important! It is best to attach the speaker with special double-sided nuts, which are used in the furniture industry.

Now we start assembling the subwoofer case. How to make a subwoofer for your computer? Insert the drill into the drill, the diameter should be half the diameter of the screws used.
We start drilling at those points where the wall will be attached to other walls and bars.
Now let's use some glue. Apply glue with a generous layer at the junction points of the bars and walls. It contributes to the performance of two functions - to increase the strength of the case and to seal the joints.
We connect the walls with self-tapping screws. We screw them all the way in, since the strength in the structure of the subwoofer case is critical. The corners should be even.
We attach the speaker. At the junction of the speaker and the wall, you need to coat it with a sealant.
We drill an exit hole through which the wires will pass.
We stretch the wires through the hole, cover the hole with sealant.
Next, we proceed to soundproofing. The inside of the cabinet needs to be pasted over with sound-absorbing material, which contributes to the “softness” of the bass of the subwoofer. The presence of such material reduces the pressure on the walls.
We fix the back wall.

Basically, the constructed subwoofer is ready. The final touch is to check the build quality. We turn on the music and check for extraneous sounds and noises.

Important! If you want to give your product a beautiful appearance, then the plywood can be painted in the appropriate color or covered with fabric.

How to make a subwoofer for a car?

Let's consider how to independently make a subwoofer for your steel friend from ordinary speakers.

Materials and tools for work

To do this, it is necessary to prepare the following materials in advance:

speaker - you should not use a used device, it is best to purchase a high-quality product with all the documents in the store;
protective grill;
glue good quality- best of all epoxy;
an outlet that facilitates connection;
fiberglass;
wire with a diameter of 3 mm;
brush;
plywood;
chipboard sheet, the thickness of which corresponds to 16 mm;
self-tapping screws and nuts that are used in the woodworking industry;
bolts;
polyethylene;
universal putty;
masking tape.

To work, we need the following tools:

drill or screwdriver;
jigsaw for wood.

Design

How to make a subwoofer from ordinary speakers with your own hands:

We select a high-quality speaker. The more power it has, the louder the sound will be.
We turn to the design of the subwoofer box - similarly, you can use special software. Since we are building a subwoofer for a car, we need a box with the highest efficiency, or it is also called a 6th level bandpass.

Important! The sixth level bandpass looks like a rectangular cube object with one bridge inside. Our speaker will be fixed on it. In addition, such a bandpass has two holes, thanks to which the phase-inverter chambers are installed. In the absence of cameras, different tubes can be used. For example, pipes made of metal, polyethylene or just paper are quite suitable.

It is very important that the housing is completely sealed. For this we use felt, foam rubber or ordinary cotton wool. The sealant layer inside should be about two centimeters.
The roof of the subwoofer must have a removable structure and have high strength at the joint. Therefore, we use a layer of foam rubber, additionally strengthen the structure.

Important! Computer utility WinlSD 0.44 helps to prepare all sizes correctly. Based on the speaker's capabilities, it will calculate the optimum values for your cabinet. In this case, your task is to clearly and competently translate the figures provided into reality. The sound in this case will meet all expectations. It comes out clean and loud.

Place for a subwoofer

Now we need to find a place for our subwoofer. The most ideal option is to install it in the wing, but right or left - you decide for yourself. Some cars have a special configuration in the right fender, which provides more room for a subwoofer.

Important! When choosing a medium speaker, a minimum of 28 liters of volume is required for its normal functioning. The configuration and volume of the box itself turns out to be large, but this is not so important.

How to make a subwoofer for a car at home:

We spread the trunk with plastic wrap, then glue the lining with masking tape in two layers.
We cut the fiberglass into pieces that correspond to the dimensions of 200 × 200.
We dilute epoxy glue. To do this, mix a can of resin and a can of hardener.

Important! If you take one of the suggested substances more than the norm, then the glue will become thick very quickly, and you will not be able to work with it efficiently. The ideal ratio is 1: 1.

Lubricate the cut workpieces with epoxy glue, overlap them with adhesive tape.
We glue the back wall of a self-made subwoofer with fiberglass. To do this, you need to lay three or even four layers of material.
Let the product dry completely within 24 hours.
The next day, remove the resulting shell. Its thickness will need to be increased outside the trunk.
Now we proceed to the bottom of the subwoofer, the top of which is made in the form of loops.
We attach the front wall with self-tapping screws.
The joints should be coated with epoxy glue.

Fine work

After the body of the homemade sub has been designed, it is necessary to prepare it for an acoustic terminal, or the so-called speaker. On one of its walls, which are on the side, it is necessary to outline the point of the future hole. This can be done using an ordinary school compasses.

Important! Subwoofers for a car with a powerful sound are obtained when it is shielded with a small box. This is no longer an area of homemade subwoofer construction, but a real art form. This eliminates the various overtones that may arise from the rather flimsy construction of the acoustic terminal.

How to make a subwoofer for your car complete and perfect software outward appearance and sound:

We process the previously made square box with PVA glue, fasten it with self-tapping screws to the sidewall where the hole was cut.
Now we use a plane, with which we cut off all the protruding edges of the body.

Important! In addition to the above skills, in this case you must have the skill of a carpenter, otherwise you will not be able to cope with such a task.

There is a jumper inside our box. Next, using an electric jigsaw, cut a hole on the front panel.
In this place we install the speaker, which is attached with self-tapping screws and glue.

Protective measures

When everything is ready, do not rush and immediately connect the homemade device. The creation must be protected from condensation and moisture. Moisture has a destructive effect on wood, and in our creation there is a thin sheet of chipboard.

In order to secure and protect the case, it should be impregnated with a special nitro varnish, which is used in the furniture industry. In addition, it is imperative to impregnate the inside of the front panel.

Important! This procedure must be carried out in an open space so that varnish poisoning does not occur.

Video

Making a subwoofer out of an ordinary speaker is not a task for an amateur. A variety of knowledge and skills will be required here, but if you have them together with an irresistible desire to create the perfect speaker system, then everything is only in your hands. We wish you success!

Good day to all. As usual, many music lovers are thinking about how to make the sound better, louder and better, but few know that you can do it yourself. So, in this article I will tell you how to make a subwoofer using CV technology with your own hands.

And so, first of all, we need a little patience, perseverance and relatively straight arms, as well as the speaker itself, in my case it is a Soviet speaker 25 GDN 3-4 for 25 watts of nominal power, it was taken from the AC-30 speaker system, I I chose, since the dimensions of the speaker itself are small, therefore, the subwoofer itself will not turn out to be so bulky, and the quality of its sound is acceptable for low frequencies, since it has a large weighty magnet. I restored the speaker a little by gluing a red cone to the diffuser, otherwise the speaker was as good as new.

The next stage, which is necessary in the assembly, is the material itself, from which the CW (quarter-wave resonator) will be assembled; it was more appropriate to make it from chipboard 18 mm thick, since this is the "golden mean" of the thickness that is needed for a strong frame.

Also, you will need a few tools, in this case a screwdriver, screws 45 mm long, silicone sealant for sealing the sub, a hacksaw for wood, or it will be better if you have a circular, a jigsaw, in my case an electric one.

The diagram shows the dimensions for a 4-inch speaker, just what you need, the setting is about 37-39 Hz.

And so, everything is there, you can assemble a subwoofer.

First of all, I sawed the chipboard into its component parts.

Sawing was done with a hacksaw borrowed from my father, but if you have a circular, then everything will be even more even and cut off all the parts faster.

In the photo, two sides of the frame are marked, which after we cut into two parts, 18 cm high and 36 cm long.

Next, I cut out three partitions, the so-called air guides, each measuring 14cm in length and 18cm in height.

Now you can put everything together using self-tapping screws.

For the air to escape, it is necessary to put a partition, in my case its length is 24cm.

Then the third partition at the back.

We cut out a hole for the speaker in the front board 21 cm long with a jigsaw.

The next thing I did was screw on the back and front covers.

Then he screwed on the speaker, having previously coated it with sealant.

The only thing left to do is to pass the wires and bring the clamps to the speaker to connect the wires to them.

Having smeared the entire side with a sealant, you can plant the remaining cover, tightening it "conscientiously" so as not to feel the air from all the cracks.

On this, the subwoofer is ready, if desired, it can be embellished with Carpet or carbon fiber. The result is a good buffer, the bass sound is very pleasant, no cracks, all the air comes out only from the port. As a result, for small costs, namely screws, sealant, chipboard and the speaker itself, you can buy a total of less than 1000 rubles, in my case I bought only screws and sealant. Happy everyone

How to make a subwoofer box correctly

Preparation

In order to make a case for a subwoofer yourself, you will need:

Drawing;
Materials: plywood or MDF, glue, self-tapping screws, terminal block, wire for connection;
Tools - jigsaw, screwdriver, pencil, bore template or compasses.

Drawing

Having on hand the parameters of the hull for the sub (volume, area and length of the port), you can make a drawing yourself by using special programs(in my opinion, Google's SketchUp is the most convenient for this). But if the box is made for yourself, then there is no point in wasting time studying the software and doing everything the old fashioned way - by hand.

If you do not know how to calculate the corpus, then read the material. You can also order a paid calculation on the Internet, as a rule, a clear drawing for manufacturing is attached to it.

An example of a drawing of a housing with a bass reflex (FI)

Materials and fasteners

Body material

In order to make a box for a subwoofer, you need a material that should vibrate as little as possible. From experience - it is best to use MDF (not painted, not laminated, etc.)

MDF (MDF - Medium Density Fibreboard). In Russian - medium density fiberboard.

MDF is easy to process, has good density, due to its structure it has no resonances and does not stratify - the bass in such a box is soft and dense. MDF is more expensive than plywood, it is “afraid” of moisture.

Plywood is the most common option; it is cheaper than MDF.

Do not use chipboard and old furniture for making a box for a subwoofer. A plywood or MDF cabinet will always sound better.

With sufficient wall thickness, it is not necessary to glue the inside of the housing with vibration isolation, etc.!

Do not use material thinner than 18 mm. and the larger the volume of your case, the thicker the walls should be.

In many large stores selling sheet material, there is a service for cutting to your size, there they will cut the perfect parts on the machine for you, you just have to assemble the body.

Fasteners

For fastening, it is best to use yellow self-tapping screws length at least 2 times the wall thickness. Blacks often have their heads broken off, they are thinner and not as strong. An advanced solution is furniture bolts, but if this is your first sub, it will be easier with self-tapping screws.

Yellow self-tapping screws, black self-tapping screws, furniture bolts.

Cage nuts for attaching the subwoofer to the case - it's cool! The sub can also be fixed on self-tapping screws, but with the bolts in the mortgages, the speaker is attracted as much as possible, and, if necessary, it can be removed and installed as many times as necessary without damage. And the polished hex bolts look really cool.

Cage nut bolt

Glue

If you are sawing the walls with a jigsaw or a hand circular saw, the glue will additionally act as a sealant between uneven edges; any liquid nails on wood will do for this. If you dissolve the material on the machine and the edges of the walls of the case are ideal, then you do not need to use glue, it will be enough to smear the joints from the inside.

Terminal block

You can also bring out the wires directly, but it is better to make a box for the subwoofer with a terminal block.

Terminal block for housing

Use threaded options - they are more reliable. For round seats, it is convenient to cut a hole with a nozzle.

Wires

You will need a piece of wire to connect the sub coil to the lead-out terminal block. Take any copper wire no thinner than 4 mm. in most cases this will be sufficient.

Instruments

You will need:

A circular saw- for cutting material, it can be manual or stationary, it all depends on your capabilities. It is better not to saw with a jigsaw, the edges will be too uneven, even if you attach the guide bar, since the file can still walk.

Jigsaw- for cutting a hole for the speaker and for the terminal block, it can also be a router, with its help the holes will turn out to be even and neat. To cut the wall for a round terminal block, you can use a saw attachment. Choose the right jigsaw blade for the job you are doing.
Screwdriver- for tightening screws and drilling holes.

Sawing parts

So, you have decided on the shape for the sub box and you have a drawing.

Mark the sheet in detail and cut according to the applied dimensions. Use a blade with a large number of teeth, the smaller the tooth size of the circular saw blade, the less chipping will turn out and their size will be insignificant.

If you are using a manual circular and your hand is not full, better to use a guide, so as not to accidentally "fill up" the cut.

It is better to do this work together, since it is not convenient enough to turn large sheets of paper alone and hold them during work.

Below good video from Rockford Fosgate, though in English, but everything is clear without translation - selection of the shape of the case, ruling of parts, sawing.

Assembling the enclosure for the subwoofer

To correctly make a box for a subwoofer, before screwing in the self-tapping screw, drill a hole for it with a thin drill, this will increase the strength of the attachment and protect the plywood from delamination. Distribute the number of screws evenly along the length of the side and make sure that they do not meet at the corners.

Almost always a template for cutting a bore hole comes with a sub; it can be part of the box or be a separate attachment. Cut out the template, transfer it to the front side of the box and cut it out with a jigsaw or router.

Bore template (cut out of the box)

If you do not have such a template, then you will have to arm yourself with a compass. Be very careful when marking and cutting the hole for the speaker! The basket shelf is almost always narrow. Cut out less than it should be - the subwoofer basket will not fit into the hole, cut out a little more or not evenly - the sub will not sit tightly or the screws for fastening will hang in the air.

For weighty subwoofers, it is recommended to make a double front wall to eliminate vibrations during speaker operation.

Double front wall

With a large body, double walls may not be enough and in some cases it will be useful to use spacers.

Spacer and stiffener options

Please note that all wire entry channels, terminal blocks, etc. must be sealed, internal partitions (port walls) must not have gaps.

It is convenient to cut the hole for the round terminal block using a nozzle, when installing it, do not forget to glue it around the perimeter.

When tightening the screws, do not overdo it, so as not to rip off and do not forget to pre-drill holes for them.

If you use cage nuts to mount the speaker, then pre-install it in the seat, precisely mark the drilling spots, remove the speaker and drill through the front wall according to the marks (make sure that the drill is always perpendicular to the plane). Select drill thickness in accordance with the diameter of the cage nuts. Install the nuts into the prepared holes from the inside of the body so that they do not fall out inward when tightening the bolts into them.

Cage nuts on the inside of the front wall

When screwing on the speaker, do not forget to connect it to the terminal block, for this you can solder the wires to it or use special terminals.

Informative video of assembly and gluing on the example of a serial Rockford subic.

If your cabinet has been properly sized, sealed, sturdy and wall-thick enough, the sound will definitely please you.

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