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How to make an active subwoofer with your own hands. Do-it-yourself subwoofer: how to make, theory, diagrams. Installing the subwoofer backlight

I spent the next week calculating the subwoofer. I downloaded several programs for calculating subwoofer enclosures (DLSBox2000, JBL-Speakershop, WinISD...) I liked the DLSBox2000 program most of all. With her help I calculated the sub. And this is what happened - the efficiency of this design (FI) for my speaker is 76%, volume - 37 lire (external dimensions 45x35x35cm), bass reflex 75x100mm. (diameter/length).

Then I drew a sketch on paper and began making it.

I screwed all the walls together with 50mm long screws. All connections are made with PVA glue (advice – don’t waste the glue, the excess will squeeze out). Inside, for greater reliability, I coated the seams with silicone sealant. In principle, this is not necessary, but it’s better to miss and forget than to take it apart again later.

Next I started puttingty. I used two-component automotive putty (you can make putty yourself by mixing small sawdust and PVA glue, as an option). Once the putty was dry, I sanded the body until it was almost perfectly flat.

Then I cut out holes for the bass reflex, socket, and pocket handles.

Let's assemble the subwoofer to see how it sounds.

All my doubts about the correct calculation of the volume of the box were instantly dispelled - the homemade subwoofer played soft, even bass. Having made sure that nothing was whistling anywhere, I removed the “accessories” and began to cover the case with self-adhesive paper with a leather texture. Collected.

Subwoofer manufacturing costs:
Semtoni woofer 10”(25 cm) 350w(rms, max) – 1100 rubles.
Chipboard 20mm. – free, found in the attic
PVA glue – free, already in stock
Self-tapping screws 50mm. 100 pieces. – 26 rubles
Silicone sealant, transparent – ​​59 rubles
Sealant gun – 40 rubles
Socket with terminals – 65 rubles
Speaker wire 1m. – 60 rubles
Bass reflex 75x100mm. – 40 rubles
Handles “Pockets” 2 pcs. - 100 rubles

Total about 1800 rubles.

A true music lover does not like to listen to music through standard computer speakers. A good speaker system is chosen based on personal preferences. Such a pleasure is not cheap; in addition, sometimes difficulties arise with selecting speakers with 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 is derived 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 a “bass speaker”.

Subwoofers are divided into two types:

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

Choosing a speaker In order to choose a speaker, you need to decide on the dimensions. The following models are available on the modern market:

• Speakers with a 6-inch subwoofer typically provide an additional source of mid-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 sound system.
• Speakers using an 8-inch subwoofer are used for additional front-facing bass.
• The ideal speakers for a subwoofer in a car are speakers of 10 inches or more. They really have high-quality sound and fill the space with a powerful and pleasant vibration of sound. The speakers are placed in a closed compact housing or the so-called “closed box”, which is capable of providing good sound pressure. The best option for the 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 large car interiors. In this case, a box for a speaker of this diameter should be about 90 liters and occupy the entire luggage compartment. In addition, with such dynamics, you can become slightly deaf, so this option is unlikely to be implemented.

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

The power of the speakers is definitely a difficult decision to make. There is only one rule, which is that the power of the speaker should be greater than the power of the amplifier. No speaker can function at maximum power for long, so it must have a “safety margin”.

Important! Users do not always have enough sound coming from a home theater. This problem is easily solved with the help of additional speakers.

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

Important! After some time (sometimes this situation can happen right away), the disturbed balance will begin to terribly hurt the ears.

How to make a subwoofer for a computer?

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

1. selection of materials;
2. body design;
3. subwoofer assembly.

Selection of materials

How to make a subwoofer at home? When starting all work, you should select the necessary materials for making 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 - help connect the speaker to the player; they must perfectly match the connectors of your device;
• wires - used to connect the subwoofer;
• plywood with a multilayer base;
• trimmings of plumbing pipe;
• wood screws, which can be from the smallest to 50 mm in length; wooden blocks having different sections, which can be from 20x20 mm or more;
• silicone sealant; hard foam rubber or felt;
• PVA glue;
• dye.

Having prepared the necessary materials, you should collect the required tools:

1. a hacksaw for wood, which would have fine teeth;
2. chisel;
3. electric drill;
4. file;
5. jigsaw;
6. compass;
7. simple pencil;
8. iron ruler;
9. screwdriver;
10. screwdriver;
11. sandpaper - from coarse to “zero”.

Designing the enclosure We begin to design the enclosure of the future subwoofer. To do 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 data on all the technical characteristics of the speaker. These include total quality factor, free space resonance frequency, and equivalent volume. All these values ​​are present in the passport data.

We download a special program to the computer device. We enter all the speaker data into the software product. Based on the values ​​provided, the program will calculate the optimal dimensions of the subwoofer box for you.

Important! The WinISD 0.44 program is capable of designing 4 types of subwoofers. The most optimal box, which is capable of operating with maximum efficiency, is a bandpass. The speaker of such a device is attached to a jumper located inside the box. This subwoofer is equipped with two chambers and two bass reflexes. To make a bass reflex, you can use trimmings of a plumbing pipe. The program can calculate the length on its own, but you must specify the diameter value.

Now let's proceed directly to designing the subwoofer box itself. All actions should be carried out slowly, since the slightest inaccuracy in measurements can cause inconvenience, and the whole work will have to start all over again.

Subwoofer assembly

Before you begin 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 pencil, we draw the contours of the future box on a sheet of plywood.
• We cut the plywood sheet using a hacksaw or jigsaw with a speed controller.

Important! You should cut slowly, without rushing, because if you rush, the plywood can delaminate, which will negatively affect the sound quality of the subwoofer in the future.

• To ensure that all edges are perfectly smooth and even, we clean them with special care with a file and sandpaper. We fasten the walls of the subwoofer together with bars, so you need to set aside the required length of the bars.
• We cut a hole for the speaker. The speaker will be located inside the subwoofer.
• In the jumper between the chambers, draw a circle with a compass, having a diameter slightly larger than the speaker diffuser.
• The edges must be perfectly even and smooth; to do this, we clean them with a file and sandpaper.

Important! When processing with a file, it should be held at a slight angle to avoid delamination of the plywood.

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

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

• Solder the wires and necessary connectors to the speaker. The locations for attaching the wires can be found in the speaker instructions itself.
• We attach the speaker to the resulting hole. We make a mark for attaching the speaker to the sheet and drill.

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

• Now let's start assembling the subwoofer housing. How to make a subwoofer for a computer? We insert a drill into the drill, the diameter should be two times smaller than the diameter of the screws used.
• We begin to drill at those points where the wall will be attached to other walls and bars.
• Now let's use glue. At the junction points of the bars and walls, apply a generous layer of glue. It helps to perform two functions - increasing the strength of the body and sealing joints.
• We connect the walls with self-tapping screws. We screw them in all the way, since strength in the design of the subwoofer housing is critical. The corners must be straight.
• Attach the speaker. At the junction of the speaker and the wall you need to coat it with sealant.
• We drill an outlet hole through which the wires will pass.
• We pull the wires through the hole and cover the hole with sealant.
• Next we move on to soundproofing. The inside of the case must be covered with sound-absorbing material, which contributes to the “softness” of the subwoofer’s bass. The presence of such material reduces the pressure on the walls.
• We attach the back wall.

In principle, the designed subwoofer is ready. The final touch is to check the build quality. We turn on the music and check for any extraneous sounds or noises.

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

How to make a subwoofer for a car?

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

Materials and tools for work

To do this, you need to prepare the following materials in advance:

1. speaker - you should not use a device that has been used; it is best to purchase a high-quality product with all the documents in the store;
2. protective grille;
3. good quality glue - epoxy is best;
4. a socket that facilitates connection;
5. fiberglass;
6. wire having a diameter of 3 mm;
7. brush;
8. plywood;
9. chipboard sheet, the thickness of which corresponds to 16 mm;
10. self-tapping screws and nuts, which are used in the woodworking industry;
11. bolts;
12. polyethylene;
13. universal putty;
14. masking tape.

To work we will 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.
• Let's move on to designing the subwoofer box - similarly, you can use special software. Since we are building a subwoofer for a car, we will need a box with the highest efficiency, or it is also called a level 6 bandpass.

Important! The sixth level bandpass looks like a cubic rectangular object, inside of which there is one jumper. Our speaker will be fixed to it. In addition, such a bandpass has two holes, thanks to which bass reflex cameras are installed. In the absence of cameras, various tubes can be used. For example, tubes made of metal, polyethylene or just paper are quite suitable.

• It is very important that the housing is completely sealed. To do 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 and further strengthen the structure.

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

Subwoofer space

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 wing, and there is more space for installing a subwoofer.

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

How to make a subwoofer for a car at home:

• We line the trunk with plastic wrap, then cover the trim with masking tape in two layers.
• We cut the fiberglass into pieces that correspond to 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 more than the recommended amount of one of the proposed substances, 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 pieces with epoxy glue and overlap them with tape.
• We cover the back wall of a self-made subwoofer with fiberglass. To do this, you need to lay three or even four layers of material.
• During the day, let the product dry completely.
• The next day we 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 subwoofer has been designed, it is necessary to prepare it for the acoustic terminal, or the so-called speaker. On one of its walls, which are located on the side, it is necessary to mark the point of the future hole. This can be done by using an ordinary school compass.

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

How to make a car subwoofer complete and ideal in appearance and sound:

• We process the previously made square-shaped box with PVA glue and screw it using self-tapping screws to the side where the hole was cut out.
• Now we use a plane, which we use to 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 in the front panel.
• In this place we install the speaker, which is attached using 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 our creation contains a thin sheet of chipboard.

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 to prevent varnish poisoning.

Video

Making a subwoofer from an ordinary speaker is not a task for an amateur. This will require a variety of knowledge and skills, but if you have them along with an irresistible desire to create the ideal acoustic system, then everything is in your hands. We wish you success!

I decided to write this article specifically for those who want, but for one reason or another cannot afford to purchase a subwoofer. This article contains step-by-step instructions on how to assemble a subwoofer with your own hands.

I will try to explain it in an accessible language for inexperienced people, and if possible, show it - that a subwoofer is not at all difficult as it may seem at first glance.

If you really want to, but you can’t, then you can!

Many people have this word on the tip of their tongue, but not everyone understands what it is.

SUBWOOFER comes from two words SUB and WOOFER - literally translated - subwoofer, i.e. speaker system for reproducing sound at lower frequencies (from approximately 20 to 200 Hz). Many people call it a “bass speaker”. Subwoofers can be active or passive. Active means that the speaker body houses an amplifier and power supply, Passive means it needs an external amplifier.

The following abbreviations are also used in the text:

AC is an acoustic system, or simply a “speaker”.

A speaker is also a loudspeaker, but a “dynamic head” would be more correct.

LFO - low frequency signal generator. (low frequencies mean frequencies from 20 to 20000 Hz)

ULF - amplifier of low-frequency signals.

Step one.

Tool and material.

To make a subwoofer we need to find:

1. Self-confidence, the desire to relentlessly go to the end and be ready for material costs (maybe it will work out well!).

2. A good, proven tool, namely:

Wood saw;

Chisel;

A set of files of various calibers and types: flat, triangular, round;

Skins (from small to large);

Electric drill;

Screwdriver (you can also use a screwdriver);

Jigsaw (even better - jigsaw);

Ruler, pen, pencil, sheet of paper and other office supplies;

A compass (preferably with a “wingspan” of 20-25 cm);

PVA glue, auto sealant, wood glue;

Building materials, namely: plywood with a thickness of 10mm to 20mm, chipboard - possible but not advisable, wooden blocks 20x20, 30x30, 40x40, etc.

A mountain of self-tapping screws from 10mm to 50mm, we will need a lot of them!

3. a computer on which it is highly desirable to install the JBLSpeakerShop program.

Loudspeaker (speaker) parameters.

Each of us has a first name, last name, and patronymic.

Each of us has unique facial features, eye color, fingerprints, and retinal patterns. There are no identical people in the world.

In the same way, no two speakers are the same; each of them has its own unique parameters. Even if you take two identical speakers made at the same factory on the same day, their parameters will differ, of course slightly, but this small difference can be important. What am I saying, but to the fact that before we start making a subwoofer, we MUST calculate the main parameters of our speaker. Whether you bought it in a store, unscrewed it from an old speaker, or a friend brought it from the garage, in any case you need to measure its characteristics. In the future, based on these parameters, we will choose the type of box for the subwoofer.

We will write down the parameters necessary to calculate the subwoofer on a piece of paper and save it until the moment when the sound quality of the manufactured “boom box” is completely satisfactory.

So, let's begin. Since most of the currently existing programs for calculating AC boxes use the Till-Small parameters, we will calculate them.
In order to start calculating the box, we need the following parameters:
Pnom - Nominal power of the speaker, given in the brand of the head (75GDN-1 75W).
Fs - Self-resonance frequency of the speaker in open space.
Fc - Resonant frequency in a closed box.
Qts - Total quality factor at resonant frequency.
Qes - Electrical quality factor at resonant frequency.
Qms - Mechanical quality factor at resonant frequency.
Vas - Equivalent speaker volume. D - Effective diffuser diameter.

Xmax - Maximum diffuser displacement.

It will be good to read about all the parameters of T-S - read.

Low frequency generator - you can take any one, for example G3-109 or similar. If there is no generator, then you can use a computer. We connect an amplifier to the linear output of the sound card, and from the output of the amplifier, through a 1KOM resistor, we connect the speaker under test. The resistor power should be 2W or more, otherwise it will get very hot. In principle, everything is ready. If we use a computer instead of a generator, then we need to download a program - LFO, there are a huge number of them on the network.

So, let's begin.

We hang the speaker on a rope in the center of the room to the ceiling, perhaps by a chandelier or in some other way, the main thing is that there are no objects nearby, this can affect the accuracy of the measurement.

Everything is connected, we launch the LFO program, set the frequency to 1000Hz. On the computer, set the volume to the middle position to eliminate distortion of the signal shape. connect the multimeter to the output of the amplifier. By adjusting the volume on the amplifier we set the voltage to 20V.

We connect the voltmeter directly to the speaker.

We set the generator frequency to approximately 5-10 Hz and gradually increase the frequency and monitor the voltmeter readings. We need to find the resonant frequency of the speaker, at this frequency the voltmeter will show the maximum voltage, then it will begin to decrease. So the voltmeter showed the maximum value - we write it down on our sheet as Umax. Then we record the frequency of the generator at which the maximum voltage value is recorded, this will be Fs - the resonant frequency. Now we need to find the minimum amplitude value. We again begin to gradually increase the frequency relative to Fs until the voltmeter readings stop changing, we write this value as Umin, with a further increase in frequency the amplitude will increase again, but this is no longer important to us.

These are the frequencies with which we will determine the quality factor of the speaker. Previously, I calculated these parameters manually, calculated them using the formulas Uav, Qts, Qes, Qms. Now there is a useful program TSCalc, you need to download it right now - download it. Working with it is simply simple; we substitute the values ​​and get the result. First you need to find out Rmax, to do this we multiply Umax by 1000 and write the value on a piece of paper. You will also need to measure the speaker's DC resistance using an ohmmeter, write it as Re.

Now let’s substitute the values ​​of Rmax and Re into the program and find Rx. Divide Rx by 1000 and get Uav. Now let's find F1 and F2. We begin to reduce the frequency relative to Fs “down” and when the voltmeter shows the voltage Uav we write down F1, now the same thing only “up” from Fs and write down the value of F2. Now we substitute the values ​​of Fs, F1, F2 into the program. And we get the values ​​Qes, Qms, Qts.

It's time for the pre-prepared box.

We take our speaker and screw it to the box with the magnet facing outwards, there is no fundamental difference in this, it’s just more convenient. Now we find the resonant frequency again, but write it as Fc.

We substitute the value of Fs, Fc and the known volume of the box, we get the value Vas - the equivalent volume.

Well, that's basically all. The effective diameter of the diffuser and its maximum displacement are measured using an ordinary ruler. Don't forget to write down the values ​​on the sheet.

Step three.

Types of boxes.

Now we have a speaker, we have its real parameters, we can start choosing a box.

I want to disappoint you right away. It is based on the parameters of the speaker that the type of housing is selected. I'm not saying that you won't be able to assemble the box you want with it, it just may not sound the same as it would sound in the "native" box.

So, types of boxes, or options for subwoofers.

Option one - Free emitter or Free air.

This option may be suitable for speakers with Fs above 100Hz.

It still won’t make a traveling subwoofer, since its parameters are close to mid-frequency speakers.

For example, it can be built into the rear parcel shelf of a car.<0,8...1, оптимально 0,7

Of course, you can try to make something else out of it, but it’s better to look for another speaker.

Option two - Closed Box or Closed Box.

Select this box if Qts

The inside of the box is filled with sound-absorbing material, cotton wool, felt, or others.

This version has the lowest efficiency.

Option three - Bass reflex or Vented Box.

Choose if Qts<0,6, оптимально 0,39

The speaker must have a flexible and durable suspension, because... performs a gigantic amount of work; at maximum power supplied, the diffuser vibrates a huge amount of air, most of which “flies into the chimney”

Option four - Passive Radiator.

A passive radiator is like a bass reflex, only instead of a pipe there is an emitter-membrane.

Although you can use the old speaker, remove the magnet, basket, diffuser. And glue a plate made of getinax, plexiglass or other material to the rubber suspension. Screw a weight into the center of the plate - a bolt with a nut. This weight can be used to adjust Fc.

Option five - Band Pass or Band Pass

Band Pass can be transported as a Band Pass.

Band Pass 4th order - Band Pass 4th order.

Worth choosing if Fs/Qts=105

In principle, of all the other housing options, this one is the most efficient.

But at the same time, the most difficult to manufacture, two cameras and two bass reflexes.

Band Pass 6th order A - Band Pass 6th order class A.

Band Pass 6th order B - Band Pass 6th order class B

Any of these housing options can be assembled with either one or two speakers.

You know the parameters of your speaker, what will come out of it, you have already determined it, it’s time to calculate the box.

Step four.

Box calculation.

Unpack the downloaded JBLSpeakerShop program into the root folder of the disk. Then run the setup.exe file from the DISK1 folder. The installation will begin, enter the path of the second part of the DISK2 archive. Installation completed.

Launch the program Start => Programs => JBL SpeakerShop => SpeakerShop Enclosure Module.

I won’t tell you in detail about the program, it is very simple and in principle everything is clear.

First, go to the Loudspeaker menu and enter the parameters of our head. Then, having selected the box type, click - Box - Parameters - and then click on the selected type. All that remains is to enter the volume and frequency of the desired resonance; you need to experiment with these parameters, observing the resulting graphs.

After you have selected the box parameters, click Vent, here we enter the parameters of the pipe (bass reflex), if of course there is one. All that remains is to calculate the dimensions of the box, go to the Dimensions submenu, choose the shape and size to suit your taste. In the Graphs menu - select the types of displayed graphs.

Step five, final.

Making a box.

Now, having rested a little, let’s get down to making the box. At this stage, in order not to translate precious material, you must strictly follow the rule, “measure seven times, drink once.”

We take out the prepared tools, material, patience. When choosing plywood or chipboard (whoever has what), you need to take into account that the higher the power of the speaker, the higher the thickness of the box walls and the more rigid the fastening. The best material is, of course, plywood (you shouldn’t use old, dried-out plywood - it will simply crumble), much stronger than chipboard, I don’t even understand how you can make a good subwoofer from sawdust.

We took out a ruler and a pencil, and first of all, let’s draw all the sides of the box on a sheet of plywood. Try to save money, in case you make a mistake somewhere, you will have something to correct.

Now let's cut, a good tool would be a hacksaw with a guide and fine teeth. You need to cut slowly and preferably at an angle, you don’t want the plywood to delaminate and crack. You can also use a jigsaw, preferably with a speed controller, for the reasons already stated. Saw smoothly, don’t rush, you’ll be exhausted with a file to straighten the humps and depressions.

After cutting, you still have to work with a file, you need to remove all the protruding pieces of wood, otherwise splinters, iodine, bandages.

Take out wooden blocks, choose their sizes yourself, but of course not too small or huge. Place the walls together as they should be and measure the required length of the bars.

Another crucial point in making the box is the huge hole for the speaker. First, using a compass, we mark a circle for the speaker, slightly larger than the diameter of the diffuser along with the rubber surround. And another smaller circle, equal to the radius of the drill and adding another 2-3mm. Here are a few ways to make holes in a piece of plywood. Don’t look for a drill, there are hardly any drills with a diameter of 100-300mm in the world, and you will need a giant drill. Take a drill with a diameter of 10-15mm, a regular electric drill.

Drill by laying your piece of plywood on some other scrap piece of wood, this will save the bottom surface a little from cracking. Now we drill holes along the inner circumference at a distance of 1-2 mm from each other. When finished, take a narrow chisel and a hammer and punch the bridges between the holes, then knock out the resulting pancake. We take the largest round file, or better yet a rasp, and slowly, again at a slight angle, align the circle along the drawn line. Sharp corners on the front side can be rounded. In the same way we make holes for the bass reflex. Another way: draw a circle with the radius of the diffuser and a hole inside, and then use a jigsaw to cut along the line. Faster, but more chips! Attach the speaker to the hole, if the “hole” suits you, drill holes for fastening the head, and for fastening you can use screw-in metal double-sided nuts, they are used in the furniture industry.

Don't forget the plug! It is better to use concert acoustics - more reliable and practical.

Well, we’ve made all the walls, holes for the speaker and bass reflex, cut the bars, and we’ll assemble them.

Do not screw the back wall yet, it will still serve us. Attach the speaker, from the outside or from the inside, as you like and depending on the design of the speaker. Coat the junction of the plywood with the speaker with autosealant, being careful not to get it on the diffuser. Auto sealant - will ensure tightness and can be easily removed if you suddenly want to change the head for another one or during repairs.

Bass reflex - you can use a piece of plumbing pipe, an aluminum pipe, or basically any pipe you have (except for metal water and sewer pipes).

In the program, enter its dimensions and get the length. The bass reflex can be square, then you will need to show your imagination in its manufacture. It will also need to be secured, but not tightly yet.

How to make a damper. The damper material can be: felt, hard foam rubber, cotton wool, thick fleece, etc.

Turn on the music, the louder the better, listen for any extraneous noise, whistling, or rustling. If it whistles, it means there is a hole or gap left unclosed somewhere in the drawer, cover it with putty or sealant, and fill it with glue. If it rustles, the damper may be touching the moving speaker cone.

Now the final external processing of the box, the corners can be rounded, thoroughly sanded, and the cracks and holes can be covered with mastic or putty.

In the end, you can cover the subwoofer with vorsonite or some other material, put decorative grilles on the speaker and bass inertizer, screw on the legs if you are going to use it indoors, your imagination will tell you here.

Well, that seems to be all! I hope all my writing has helped someone! Thank you for reading to the end, all the best to you, success!

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The thought of assembling a subwoofer with my own hands has been haunting me for several months now. And then one day, when I went to the Radio Shop, a Semtoni woofer caught my eye, and I decided to buy it...

I spent the next week doing calculations. I downloaded several programs for calculating subwoofer enclosures (DLSBox2000, JBL-Speakershop, WinISD...) I liked the DLSBox2000 program most of all. With her help I did the calculations. And this is what happened - the efficiency of this design (FI) for my speaker is 76%, volume - 37 lire (external dimensions 45x35x35cm), bass reflex 75x100mm. (diameter/length).

Then I drew a sketch on paper and began making it.

I screwed all the walls together with 50mm long screws. All connections are made with PVA glue (advice - don’t skimp on the glue, the excess will squeeze out). Inside, for greater reliability, I coated the seams with silicone sealant. In principle, this is not necessary, but it’s better to miss and forget than to take it apart again later.

Next I started puttingty on the subwoofer body. I used two-component automotive putty (you can make putty yourself by mixing small sawdust and PVA glue, as an option). Once the putty was dry, I sanded the body until it was almost perfectly flat.

Then I cut out holes for the bass reflex, socket, and pocket handles.

I assembled the subwoofer body to see how it sounds.

All my doubts about the correct calculation of the volume of the subwoofer were instantly dispelled - a soft, even bass was playing. Having made sure that nothing was whistling anywhere, I removed the “accessories” and began to cover the case with self-adhesive paper with a leather texture. Collected.

What was needed to make a homemade subwoofer:

• Semtoni woofer 10”(25 cm) 350w(rms, max) - 1100 rubles.
• Chipboard 20mm. - free, found in the attic
• PVA glue - free, already in stock
• Self-tapping screws 50mm. 100 pieces. - 26 rubles
• Silicone sealant, transparent - 59 rubles
• Sealant gun - 40 rubles
• Socket with terminals - 65 rubles
• Speaker wire 1m. - 60 rubles
• Bass reflex 75x100mm. - 40 rubles
• Handles “Pockets” 2 pcs. - 100 rubles

Total about 1800 rubles.

How to turn a passive subwoofer into an active one

How to turn a passive subwoofer into an active one is often asked by beginners interested in improving car acoustics. If you know the difference between these types of speakers, then the conversion process will not be difficult.
The complexity of the process of how to turn a passive subwoofer into an active one lies in the fact that you need to be able to determine the difference in sound and make the correct calculations.

Subwoofer concept

It will be useful for a beginner to know what this speaker is generally intended for. Isn't it possible to just use a pair of multi-voice speakers and quietly enjoy the full sound? It turns out not.

Note. As you know, a subwoofer is designed to reproduce low frequencies that have low localization. If there were not one speaker enclosed in a separate housing, it would be difficult to determine from which point the sound is coming. It will seem unreal, too voluminous and enveloping.

In addition, if earlier, when the subwoofer was not invented (see), speakers for reproducing various frequencies, including low ones, had to be huge and expensive, then with the advent of a separate subwoofer everything was significantly simplified, both in terms of volume and and cost.

Difference

So, subwoofers are designed to reproduce low frequencies. It's clear. But why do passive and active types exist? What are the differences? Let's try to figure it out.

Passive

This sub, by its design, is a low-frequency driver enclosed in a separate housing. To achieve the required sound from it, you will have to connect it to two separate elements: an external amplifier and a crossover (see).
The latter is nothing more than a crossover filter that distributes frequencies and directs them to the speakers.

Active

This type of subwoofer already has a built-in amplifier in its design. A crossover is also built inside it.

This saves the user from the complex connection process and setting up the speaker is also quite simple.

Some users, in order not to overpay for an active subwoofer, decide to make one themselves from a passive one. The idea is interesting and fully justified in practice.

Note. Converting a passive subwoofer into an active one involves connecting it to a power amplifier and crossover, which must be built into the speaker. Only this setting requires specific knowledge.

Calculation of indicators

If we were making an active subwoofer completely from scratch, then first of all, we would need to download from the Internet or find another way a program for calculating acoustic designs.

Note. For example, it could be a GBI Speaker, which includes two more independent graphic schemes that are needed to determine the required volume and size of the housing, and also allow you to independently select two directions for the housing.

In addition, it would be necessary to find the known Thiel-Small values. By the way, they are needed in our case as well.

The fact is that the emitters installed in the speakers may not meet the above parameters. And then everything will have to be measured again.

Measurement

Started:

• First, the resonant frequency Fs is measured. This parameter specifies the frequency without any additional decoration.
  Fs is calculated as follows: the emitter is suspended in the air at a great distance from foreign objects so that this value is not influenced by external characteristics;
• It is better to measure the resonant frequency in an empty garage or other room. We hang the speaker on the ceiling;
• Open the Tone Generator program on your computer;
• The initial frequency is set to 10Hz, and then the frequency gradually increases in 1Hz steps. At the same time, you need to look at the voltmeter readings. Thanks to the graph below, you can determine the required value;

• The approximate speaker frequency Fs in 1Hz steps will be the maximum value of the voltmeter;
• To calculate the exact value, you will need to change the frequency not by 1Hz, but by five hundredths of it.

Note. Some people believe that a very low resonant frequency is ideal for a subwoofer. This is true, but partially, because for some designs such a low resonance can lead to interference.

Second meaning

• Then the total electromechanical quality factor Qts is measured. Interestingly, the quality factor has two indicators: mechanical and electrical.
  The first is determined by the choice of suspension material. Quality factor is often measured using a makeshift method: shaking. The low quality factor of the subwoofer is 0.3/0.35, and the high value is 0.5/0.6.
• The electromechanical quality factor is found using the formula, where the values ​​will be two components, one of which is lower than the resonant frequency, and the other is higher.

Equivalent volume

Finally, the third value we will need to calculate is the equivalent volume Vac:

• To determine such a volume, you will need a bass reflex box with a hole. The manufacturer has already agreed on the volume of such a box in comparison with the diameter of the speaker. Therefore, there is no need to do anything extra;
• Again, using the Tone Generator program we determine the value, as in the case of the resonant frequency. Only calculations are carried out using the following formula:

Hull alteration

In order to get high-quality sound, calculations alone are not enough. It is necessary to carefully prepare the subwoofer housing, converting it to the active version.
What have we achieved with calculations? We determined the internal volume of the box, the length and diameter of the bass reflex.

Note. It is believed that converting a passive subwoofer into an active one is much more difficult than doing everything again with your own hands. Thus, a homemade box is made with the necessary holes.

One thing you need to know: an active subwoofer (its housing) must consist of 2 compartments. The emitter or loudspeaker is located in one of the compartments, and the amplifier, crossover and power supply are in the other.

Note. From the inside, it is recommended to glue foil to the walls of the compartment where the amplifier, power supply and isolation filter will be located. It eliminates the negative effects of external fields and minimizes noise levels.

• After this, as soon as the signal is formed, it enters the amplifier, and only then into the emitter.

So, we found out that the alteration can be done with your own hands. In this case, it will be extremely useful to watch a video review on the topic or relevant photo materials.
You must act strictly according to the instructions. Thus, if everything can be accomplished, we will save a lot of money, because the price of an active subwoofer is quite high.