High-quality sound speakers for home sound reinforcement equipment reproduce low-frequency signals with a frequency of 30-50 Hz, which corresponds to a sound wavelength of 7-10 m. To effectively emit such vibrations, dynamic heads with a large diffuser diameter are needed (there are examples with a diameter of 400 mm). However, in practice, “speakers” ranging in size from 200 to 300 mm are most often used. Their natural resonant frequency is 15-30 Hz.

When a sound signal is applied to the head, its moving system oscillates, emitting in both directions sound vibrations that are equal in strength but opposite in phase, which are non-directional. The “speaker” housing is not able to isolate areas of air compression and rarefaction from one another. As a result, the sound pressure level at the listening point is low. This phenomenon is known in the art as an acoustic short circuit. This is eliminated by placing the acoustic emitter in a closed box (Fig. 1). (The symbols in the figures indicate: a - width, b - depth, c - height of the box, x - thickness of the material, (1 - thickness of the strip). Often one or even several holes are made in it, placing them in certain places in the body (Fig. 2). Such holes are called phase inverters, or bass reflectors. Their type is a passive radiator (Fig. 3), which is an unconnected dynamic head. The location of the holes on the front panel of the speaker body is chosen so that the back radiation coincides with the front one, increasing it. thereby low-frequency sound pressure.

Important for acoustic speakers are their size, shape and materials from which they are made, internal “filling” and design of the front panel. Thus, the body influences technical specifications the dynamic head installed in it and, above all, to increase its own resonant frequency. An important role here is played by the diameter of the diffuser and the displacement of the housing. With an increase in its volume and a decrease in the size of the moving system, the resonant frequency changes slightly. If a head with a large diffuser is installed in a relatively small box, the resonant frequency will change noticeably - low frequencies are “cut off”, and as a result, the effective frequency range of the speaker is narrowed. In other words, an incorrectly selected housing can degrade the playback quality of even a very good dynamic head.

For effective head output at low frequencies, Bulgarian radio amateurs recommend choosing column volumes based on the data given in the table.

When using a bass reflex, certain requirements must also be met. The hole for it should be located at a distance of at least 60-80 mm from the woofer head and 40-50 mm from the rear wall of the housing. Sound-absorbing material is also placed at the same distance from the hole. It is better if the bass reflex is located under the woofer head.

Recommended sizes for bass reflex speakers depend on the volume of the speaker and the diameter of the head diffuser. So, with a head d 125 mm installed in a housing with an internal volume of B dm3, the bass reflex pipe has d 50 (46) mm and b = 60 mm. For a loudspeaker with a volume of 16 dm3, the diameter of the diffuser is 160 mm, you need a pipe d 50 mm and length 100 mm. Accordingly, for a head d 200 mm with a volume Y = 30 dm3, the pipe dimensions will be d 75 mm, b = 100 mm. The loudspeaker has d 300 mm, with N4 = 60 dm3 the pipe should have d 75 mm and b = 220 mm.

The shape of the cabinet, both internal and external, also affects the frequency response of the speaker. The most acceptable is spherical, and the most unsuitable is a cube, when the dynamic head is located in the geometric center of one of its sides. In a cylindrical body, the most favorable location of the head is transverse (Fig. 4a), rather than longitudinal (Fig. 46), although attaching it in the latter case is much simpler.

If the housing has the most common parallelepiped shape, it is best to install the low-frequency “speaker” asymmetrically relative to the sides of the reflective board (Fig. 1).

A type of parallelepiped-shaped column is shown in Figure 5.

A loudspeaker with a housing in the form of a triangular prism (Fig. 6) or a truncated pyramid (Fig. 7, 8) has good acoustic data.

For a volume of 5-10 dm3 and a “speaker” power of 6-10 W, a box wall thickness of 8-10 mm is sufficient, and for V = 40-60 dm3 and a power of 40-100 W, the rest are made of plywood or chipboard. However, with large dimensions of the case and significant power of the dynamic head, unwanted vibrations may still occur in it. To avoid them, the walls of the column are tightened with wooden slats with a cross-section of 40 X 40 mm or metal rods d 6-10 mm (Fig. 10).

Bass reflexes are made of plastic or metal (for example, duralumin) pipes with a wall thickness of at least 2 mm.

Minerals are also used as a material for building columns. Marble comes first. Thanks to its layered structure, it dampens sound well and therefore does not experience resonant vibrations. Marble is easy to process, but the disadvantage is that it is heavy and fragile.

The walls of the case are connected to each other using one of the methods shown in Figure 11. It is easier to make a box with removable front and rear panels.

First, cut out the side walls. Before assembly, it is necessary to glue and then nail with small nails restrictive mounting rails measuring 15X15 or 20X20 mm and the length indicated in Figure 12.

The walls of the body are glued together with Universal or S-200 glue and thin nails are driven in every 15-20 mm for greater reliability of fastening. The box will be even stronger if additional bars are glued into its corners (Fig. 13). Free spaces are filled with epoxy. Based on the covering assembled in this way, the dimensions of the front and rear panels are determined. They are made from coniferous wood. Based on the existing dynamic heads, the location of the holes for them is outlined (Fig. 14).

Speakers are often decorated with decorative frames made of wooden slats with a cross-section of 15x15 mm. The radio fabric is stretched over a reflective board and secured with buttons or furniture nails.

The internal volume of the speaker is filled with some sound-absorbing material, for example glass wool. Its quantity is determined by measuring the resonant frequency. The filling of the body is considered normal if it has decreased by 10-12%. It has been experimentally established that this will require 30-40 g of glass wool or 10-15 g of polyester wool (yambolene) per 1 dm3. You can also use rags. The sound-absorbing material is placed in a thick fabric cover.

If the dimensions of the housing are correctly selected and it is carefully sealed, then when you gently press the diffuser of the low-frequency head, its moving system smoothly returns to its original position. The absence of such a phenomenon indicates the presence of acoustic losses, which reduce sound pressure at low frequencies by 1-2 dB.

The quality of sound reproduction in a car depends entirely on the location of the device in the cabin. It is also necessary to take into account all technical parameters and the resonance indicator of the “boxes”. The housing of the sound reproduction device to be used in a particular application is ideally made of suitable materials capable of providing the necessary resonance. It is for this reason that the most productive work is working with your own hands. But how to make speakers if you have never done this before? To fully understand the matter and find an answer to this question, it is necessary to understand all the nuances of creating acoustic devices. Today you will get acquainted with information that will help you create a case yourself, which will have a positive impact on your budget and give you a lot of useful experience.

What is important for speakers?

First, you need to decide on the size of the equipment. And to determine the size, you should choose a location:

• The most popular place is the trunk because there is plenty of space. Also in this compartment there are all the conditions for creating a certain resonance, which makes the sound a little different.
• You can install it near the rear windows, but then you will have to reduce the size of the cases, since large devices simply will not fit.

How to make speakers with your own hands at home? To do this, you need to take a closer look at the four stages of creation.

Measurements

To determine the dimensions of the case you need:

• Choose a location.
• Evaluate the space you occupy.
• Measure the allocated area.

Important! If the trunk is chosen as the location, then 30 centimeters is quite enough, and for a location in the rear seats - at least 15 centimeters.

What are we building from?

In order to assemble the speakers, you should choose the following materials:

• Chipboard. It will be very easy to find such material, and the affordable price tag makes its contribution. The main advantage of chipboard is its good output, which will save the car enthusiast from listening to distortions. Also, the weight of a chipboard structure will be practically unnoticeable.
• Ebonite. Solid rubber products look good, but the muffled sound is a little disappointing. In addition, you will have a very difficult time finding a rectangle-shaped piece.

Important! Also, some buyers complain about an unpleasant odor, but ebonite is more flame-resistant, unlike chipboard, so short circuits (short circuits) are not scary for it.

• Wood. You can use any wood as a body, but seasoned experts recommend giving preference to oak or pine, since their structure has a good effect on the sound. Besides, no one forgets about appearance, which in this case can be made very attractive.

Important! Wooden structures can be coated with a layer of paint, which will have a positive effect on the aesthetics of your invention.

Let's get started

How to make a speaker at home? The body is the most important component, so let’s look at its creation.

The most common and convenient option looks like this:

• Using a hacksaw, you prepare future parts from the selected material.
• Select the components on which the speakers will be attached and make holes in the central part.

Important! The diameter of the holes must be selected so that it matches the diameter of the bottom of the device.

• Next, cut out small rings that you attach to the holes you made. This will help secure the speaker well. Create a shape that resembles a plate with a knocked out bottom. Glue these rings to the finished components.
• Create a few more holes, only in the shape of a triangle. They need to be made around the above-mentioned rings. These actions will help achieve optimal sound reproduction, in which all waves will penetrate the housing.
• Take care of the inside of the structure and make small partitions. Choose a length that is identical to the length of the body. These parts will be needed to fix the bass reflex.
• Make compact ports into which terminals will later need to be threaded.

Assembly phase

To connect the case together you will need:

• Fasten all the parts using glue and screws.
• Fill the structure with padding polyester.
• Place the speaker in its place.

• Apply varnish to the invention in order to protect the material and give it a decent appearance.

Important! For painting, you can also use special wood paint, and some of the components can even be made in any other color scheme.

Sound systems

In fact, speakers are not always required. You can create acoustics in a car in another way:

• Make foam podiums. To do this, you need to create a cardboard template and place it on the place where the podium is supposed to be.
• Cut a solid base. A sheet of plywood or reinforcement can help you with this.
• Create a base from two rings. The radius of the first must be identical to the radius of the mesh, which is intended for protection. The diameter of the second ring must be kept in accordance with the size of the column.
• Connect the rings using self-tapping screws.
• Make 6 bars to recreate the slope. All parts will need to be fastened together with glue.
• Pour foam into the structure and leave until completely dry.

Important! Instead of sheets of plywood, you can take pieces of different wood. For such a task, you should choose only dry materials that do not have visible defects or cracks. In this case, it is also recommended to varnish the entire structure in order to give it reliability. If you are looking for greater efficiency, then secure all components using 2 slats.

Before a detailed consideration of the problem, we will outline the range of tasks; knowing the final goal, it will be easier to choose the right direction. Manufacturing acoustic systems with your own hands is a rare occurrence. Practiced by professionals and novice musicians when store-bought options are not satisfactory. The problem arises of integrating into furniture or high-quality listening to existing media. These are typical examples that can be solved using a set of generally accepted methods. We'll take a look at it. We do not recommend scrolling diagonally through the device of the speaker system, delve into it!

Acoustic system design

There is no chance of making an acoustic system yourself without understanding the theory. Music lovers should know that the biological species Homo Sapiens hears sound vibrations with frequencies of 16-20,000 Hz through the inner ear. When it comes to classical masterpieces, the variation is high. The lower edge is 40 Hz, the upper edge is 20,000 Hz (20 kHz). The physical meaning of this fact is that not all speakers are capable of reproducing the full spectrum at once. Relatively slow frequencies are better handled by massive subwoofers, and squeaking at the lower edge is reproduced by smaller speakers. Obviously, this means nothing to most people. And even if part of the signal disappears or is not reproduced, no one will notice it.

We believe that those who set the goal of making their own acoustic system should critically evaluate the sound. It will be useful to know that a suitable speaker has two or more speakers in order to be able to reflect the sound of a wide swath of the audible spectrum. But even in complex systems there is only one subwoofer. This is due to the fact that low frequencies cause the environment to vibrate, even penetrating through walls. It becomes unclear where exactly the bass is coming from. Consequently, there is only one low-frequency speaker – a subwoofer. But as for other things, a person will confidently say from which direction this or that special effect came (the ultrasound beam is blocked by the palm).

In connection with the above, we will divide the acoustic systems:

1. Sound in Mono format is unpopular, so we avoid touching on historical excursions.
2. Stereo sound is provided by two channels. Both contain low and high frequencies. Equal speakers equipped with a pair of speakers (bass and squeak) are better suited.
3. Surround Sound is distinguished by the presence of a larger number of channels, creating a surround sound effect. We avoid getting carried away with subtleties; traditionally, 5 speakers plus a subwoofer convey the range to music lovers. The design is varied. Research is still underway to improve the quality of acoustic transmission. The traditional arrangement is as follows: in the four corners of the room (roughly speaking) there is a speaker, the subwoofer is on the floor to the left or in the center, the front speaker is placed under the TV. The latter is in any case equipped with two or more speakers.

It is important to create correct body for each column. Low frequencies will require a wooden resonator, but for the upper end of the range it doesn’t matter. In the first case, the sides of the box serve as additional emitters. You will find a video demonstrating the overall dimensions corresponding to the wavelengths of low frequencies according to science, practically all that remains is to copy ready-made designs; the topic is devoid of relevant literature.

The range of tasks is outlined, readers understand that a homemade acoustic system is built with the following elements:

• a set of frequency speakers according to the number of channels;
• plywood, veneer, body boards;
• decorative elements, paint, varnish, stain.

Acoustics design

Initially, select the number of columns, type, location. Obviously, producing more channels than a home theater has is an unwise tactical move. A cassette recorder will only need two speakers. At least six buildings will be released for the home theater (there will be more speakers). According to the needs, accessories are built into the furniture, the quality of low frequency reproduction is poor. Now the question of choosing speakers: in the publication by Naidenko and Karpov the nomenclature is given:

1. Low frequencies - CA21RE (H397) head with an 8-inch fit.
2. Mid range - MP14RCY/P (H522) 5" head.
3. High frequencies – head 27TDC (H1149) by 27 mm.

They presented the basic principles of designing acoustic systems, proposed an electrical circuit of a filter that cuts the flow into two parts (a list of three subranges is given above), and gave the name of purchased speakers that solve the problem of creating two stereo speakers. We avoid repetition; readers can take the trouble to look through the section and find specific titles.

The next question will be the filter. We believe that National Semiconductor will not be offended if we screenshot the drawing of the Ridico translation amplifier. The figure shows an active filter with a power supply of +15, -15 volts, 5 identical microcircuits (operational amplifiers), the cutoff frequency of the subbands is calculated by the formula shown in the image (duplicated in text):

P – number Pi, known to schoolchildren (3.14); R, C – resistor and capacitance values. In the figure, R = 24 kOhm, C is silent.

Active filter powered by electric current

Taking into account the capabilities of the selected speakers, the reader will be able to select a parameter. The characteristics of the speaker's playback band are taken, the overlap junction between them is found, and the cutoff frequency is placed there. Thanks to the formula, we calculate the value of the capacitance. Avoid touching the resistance value, reason: it can (disputed fact) set the operating point of the amplifier, the transmission coefficient. On the frequency response given in the translation, which we omit, the limit is 1 kHz. Let's calculate the capacity of the specified case:

C = 1/2P Rf = 1/2 x 3.14 x 24000 x 1000 = 6.6 pF.

It’s not that big of a capacitance; it’s selected based on the maximum permissible voltage. In a circuit with sources of +15 and -15 V, it is unlikely that the nominal value exceeds the total level (30 volts), take a breakdown voltage (the reference book will help) of at least 50 volts. Do not try to install electrolytic capacitors direct current, the scheme has a chance to fly into the air. There is no point in looking for the original circuit diagram of the LM833 chip due to Sisyphean labor. Some readers will find a replacement chip that is different... we hope for your understanding.

Regarding the relatively small capacitance of the capacitors (retail and total), the description of the filter says: due to the low impedance of the heads without active components, the ratings would have to be increased. Naturally causing the appearance of distortions due to the presence of electrolytic capacitors and coils with a ferromagnetic core. Feel free to move the range division boundary, general throughput remains the same.

Passive filters will be assembled with your own hands by anyone trained in soldering in a school physics course. As a last resort, enlist the help of Gonorovsky; there is no better description of the intricacies of the passage of signals through radio-electronic lines that have nonlinear properties. The presented material interested the authors in low and high frequency filters. Those wishing to divide the signal into three parts should read works that reveal the basis of bandpass filters. The maximum permissible (or breakdown) voltage will be scanty, the nominal value will become significant. Matching the mentioned electrolytic capacitors are capacitances with a nominal value of tens of microfarads (three orders of magnitude higher than those used by an active filter).

Beginners are concerned about the issue of obtaining a voltage of +15, -15 V to power speaker systems. Wind a transformer (an example was given, PC program Trans50Hz), equip it with a full-wave rectifier (diode bridge), filter, enjoy. Finally, buy an active or passive filter. This thing is called a crossover, carefully select the speakers, correlate the ranges more accurately with the filter parameters.

For passive speaker crossovers, you will find many calculators on the Internet (http://ccs.exl.info/calc_cr.html). The calculation program takes the input impedances of the speakers and the division frequency as the initial numbers. Enter the data, the robot program will quickly provide the values ​​of capacitances and inductances. On the page below, specify the filter type (Bessel, Butterworth, Linkwitz-Riley). In our opinion, this is a task for the pros. The above active stage is formed by 2nd order Butterworth filters (rate of frequency response reduction 12 dB per octave). It concerns the frequency response (frequency response) of the system, understandable only to professionals. When in doubt, choose the middle ground. Literally check the third circle (Bessel).

Acoustics of computer speakers

I happened to watch a video on YouTube: a young man announced that he would make an acoustic system with his own hands. The talented boy: he ruined the speakers personal computer- well, none at all - I brought out an amplifier with a regulator and placed it in a matchbox (speaker system housing). Computer speakers are notorious for poor bass response. The devices themselves are small, light, and secondly, the bourgeoisie saves on materials. Where does bass come from in a speaker system? The young man took... read on!

Most expensive component music center. Hi-end acoustics cost less than a cheap apartment. Repairing and assembling speakers is a good business.

The low-frequency amplifier of the speaker system will be assembled by an advanced radio amateur; no Kulibins are needed. The volume control knob sticks out of the matchbox, the input is on one side, the output is on the other. The speakers of the old sound system are small. The young man got hold of an old loudspeaker, not of fabulous size, but solid. From a Soviet-era speaker system.

So that the sound would not disturb the air with squeaking, the clever youth knocked together one-inch boards into a box. The speaker of the old acoustic system was placed in the size of a mailbox, moved, as is done by the manufacturers of modern home theater subwoofers. I was too lazy to decorate the inside of the speaker with soundproofing. Anyone can use batting or other similar material for the acoustic system. Small speakers are placed inside oblong boxes that just contain the end of a loudspeaker. The proud youth connected one channel of the speaker system to two small speakers, the second to one large one. Works.

The young man is a fabulous fellow, he doesn’t drink in the gateway, like his peers, he doesn’t spoil future brides in his free time, he’s busy with business. As one acquaintance said: “The younger generation is forgiven for a lack of knowledge and experience, not an excess of arrogance, strengthened by indifference.”

Improvements

We decided to improve the method; we sincerely hope that the addition will help make the acoustic system itself somewhat better. Problem? The concept was invented by radio engineers and creators of acoustic systems - frequency. The vibration of the Universe has a frequency. They say that it is even inherent in a person’s aura. It’s not for nothing that every good speaker can accommodate several speakers. Large ones are intended for low frequencies, bass; others - for medium and high. Not only the size, but also their structure is different. We have already discussed this issue and refer those interested to the written reviews, which provide a classification of acoustic systems and reveal the operating principles of the most popular ones.

Computer scientists are familiar with the system buzzer, which works by interrupting the BIOS, which seems to be capable of producing one sound, but talented programmers wrote elaborate melodies on it, even with an attempt digital synthesis and voice reproduction. However, such a tweeter cannot produce bass if desired.

Why this conversation... A large speaker should not only be adapted to one of the channels, but should be given a specialization for bass. As you know, most modern compositions (We don’t take Sound Around) are designed for two channels (stereo playback). It turns out that two identical speakers (small ones) play the same notes, this makes little sense. At the same time, from the same channel, the bass is lost, and the high frequencies die on a large speaker. What should I do? We propose to introduce passive bandpass filters into the circuit, which will help split the flow into two parts. We take the diagram from a foreign publication for the simple reason that it was the first one that caught our eye. Here is a link to the original site chegdomyn.narod.ru. The radio amateur copied it from the book, we apologize to the author for not indicating the original source. This happens for the simple reason that he is unknown to us.

So, here's the picture. The words Woofer and Tweeter immediately catch your eye. As you might guess, this is, respectively, a subwoofer for low frequencies and a speaker for high frequencies. The range of musical works is covered from 50-20000 Hz, with the subwoofer accounting for the band low frequencies. Radio amateurs themselves can calculate the bandwidth using well-known formulas; for comparison, A of the first octave, as is known, is 440 Hz. We believe that such a division is suitable for our case. I would just like to find two large speakers, one for each channel. Let's look at the diagram...

Not exactly a musical scheme. In the position occupied by the system, the voice is filtered. Range 300-3000 Hz. The switch is signed Narrow, translated as a stripe. To get Wide playback, lower the terminals. Music fans may want to throw out the Narrow bandpass filter; those who like to surf Skype should avoid a hasty decision. The circuit will completely eliminate the microphone loop effect, which is known everywhere: a high-pitched buzz due to over-amplification (positive feedback). A valuable effect, even a military man knows the difficulties of using a speakerphone. The owner of the laptop is aware...

To eliminate the feedback effect, study the issue, find at what frequency the system resonates, cut off the excess with a filter. Very comfortably. Regarding popular music, we turn off the microphone, move it away from the speakers (in the case of karaoke), and start singing. We will leave the high and low pass filters unchanged, the products were calculated by unknown Western friends. For those who have difficulty reading foreign drawings, we explain that the diagram depicts (the Narrow bandpass filter is discarded):

1. Capacitance 4 µF.
2. Non-inductive resistances R1, R2 with a nominal value of 2.4 Ohm, 20 Ohm.
3. Inductance (coil) 0.27 mH.
4. Resistance R3 8 Ohms.
5. Capacitor C4 17 uF.

The speakers must match. Advice from this site. The subwoofer will be MSM 1853, the tweeter (the word has not been written off) will be PE 270-175. You can calculate the bandwidth yourself. The capital letter Ω means kOhm - no big deal, change the value. We remind you that the capacitances of parallel-connected capacitors add up, like series-connected resistors. In case it is difficult to get suitable denominations. It is unlikely that you will be able to make speakers with your own hands; it is realistic to obtain small resistance values. Do not use coils; we cut out plates of nichrome or similar alloys. After manufacturing, the resistor is varnished, a large current is not planned, and the element should not be protected.

It is easier to wind inductors yourself. It is logical to use an online calculator, by setting the capacitance, we will get the parameters: number of turns, diameter, core material, core thickness. Let's give an example, avoiding being unfounded. We visit Yandex, type something like “online inductance calculator”. We receive a number of output responses. We choose the site we like, and begin to think about how to wind the inductance of an acoustic system with a nominal value of 0.27 mH. We liked the site coil32.narod.ru, let's get started.

Initial information: inductance 0.27 mH, frame diameter 15 mm, PEL wire 0.2, winding length 40 millimeters.

The question immediately arises, seeing the calculator, where to get the nominal diameter of the insulated wire... We worked hard, found a table on the website servomotors.ru, taken from the reference book, which we present in the review, consider it for your health. The diameter of the copper is 0.2 mm, the insulated core is 0.225 mm. Feel free to feed the values ​​to the calculator, calculating the required values.

The result was a two-layer coil with 226 turns. The length of the wire was 10.88 meters with a resistance of about 6 ohms. The main parameters have been found, we begin to wind. A homemade speaker system is made in self made case, there is a place to place the filter. We connect a tweeter to one output, and a subwoofer to the other. A few words about amplification. It may happen that the amplifier stage will not support four speakers. Each circuit is characterized by a certain load capacity; you cannot jump higher. The speaker system is designed with a fixed headroom in mind; to match the load, an emitter follower is often used. The cascade that makes the circuit work, full impact on any speaker.

Parting words for beginning designers

We believe that we have helped readers understand how to properly design an acoustic system. Passive elements (capacitors, resistors, inductors) can be obtained and manufactured by anyone. All that remains is to assemble the speaker system body with your own hands. And we believe that this will not be the case. It is important to understand that music is formed by a range of frequencies that are cut off by improper manufacturing of the device. When you are planning to make a speaker system, think about it and look for the components. It is important to convey the magnificence of the melody, there will be a strong confidence: the work was not in vain. The speaker system will last a long time and will give you joy.

We believe that readers will enjoy making speaker systems with their own hands. The coming time is unique. Believe me, at the beginning of the 20th century it was impossible to obtain tons of information every day. Training resulted in hard, painstaking work. I had to rummage through the dusty shelves of libraries. Enjoy the Internet. Stradivarius impregnated the wood of his violins with a unique composition. Modern violinists continue to choose Italian examples. Think about it, 30 years have passed, the cart has been left behind.

The current generation knows the brands of adhesives and the names of materials. Necessities are sold in stores. The USSR took away the abundance of people, providing them with relative stability. Today, advantage is described by the ability to invent unique ways to earn money. A self-taught professional will cut down cabbages everywhere.

Dedicated to those who have free time

We open a popular magazine about good sound and look with pleasure at the elegant images (if not the image) of acoustic systems, and there is something to look at. Powerful towers bristle with speakers in all directions, shine with their varnished sides, crush the parquet with sharp spikes and generally evoke a feeling of deep respect. The only downside they seem to have is, of course, the price. A completely logical question arises: what if you make a copy of a monster yourself? Buying a speaker is not difficult, assembling the housing, even if it is not so beautiful, also, the coils and capacitors can be domestic, carefully soldering 3 parts is a task for a 10th grade school student.

Considering the number of ready-made modules that Ebay offers, making a good amplifier is not much more difficult. What’s not there: switching, speaker protection, A-AB-D class boards, volume controls for every taste, beautiful cases made specifically for audio, handles, legs and transformers - just know, connect. In the next article we will definitely tell you how to assemble your own amplifier, which will not be inferior to most “branded” samples costing up to 60-70 thousand rubles.

You may come across unfamiliar words later in the text. Fortunately, an unknown audiophile came to our aid and left link to your personal archive of information on acoustics and amplifiers, there really is ALL and even more, we strongly recommend that you read it.

What to make it from? Plywood, MDF, chipboard, plastic, solid wood.

The world has seen many strange acoustic structures, for example, made of concrete or cinder block. Still, the above-mentioned wood-based lumber remains the most “in demand”. Let's try to understand which one is “more correct”. The basic rule is - regardless of the material chosen, do not skimp on its quality, that is, price.

First comes the king of modern Hi-Fi and Hi-End industry - MDF, The vast majority of speakers, both expensive and cheap, are made from it. The reason is simple - low cost, ease of processing and finishing, including options with ready-made veneer, and the absence of bright resonances. With proper design, optimal results are guaranteed. We recommend it for use, nothing more to say.

Plastic- the concept is very loose, its “authority” is significantly undermined by cheap Chinese counterfeits, although it has no fewer advantages than any other material. We are passing by the problem of the inaccessible opportunity for an amateur to cast his own blanks from the desired material.

A good material for making an acoustic system enclosure can be Chipboard. Perhaps its main drawback is the many problems with finishing, no matter what you decide: paint, veneer or upholstery. Chipboard has a huge advantage: if you need to do it quickly and very cheaply, you can use a factory-made laminated chipboard (LDSP). In this case, it is unlikely that it will be possible to achieve high aesthetics, but the price and speed will leave all other contenders far behind. If we compare the resonant properties of materials in terms of suitability for speakers, chipboard takes first place, although the difference compared to MDF is small.

Capricious, but invariably desired by “seasoned audiophiles” madam plywood. There are several types of plywood - birch, coniferous, alder, laminated. Why capricious? Any plywood “leads”, that is, when the sheet dries, it changes its geometry, and chips often appear when sawing. It is also not the easiest material to finish if you want to get a “dull” matte color without visible edges, texture, or edges. The reason for enduring this torment is quite controversial: according to “experienced” people, only plywood gives that very living breath that chipboard and MDF “kill”. What I most incomprehensible is the desire to make a body out of “living” plywood and “kill” it with layers of putty, primer, paint, varnish in an attempt to hide the “terrible” joints with veins (layers of plywood), which look at their owner with silent reproach day and night . Options for special impregnation, at least with the same “Danish oil”, are much preferable; these dark “stripes” on the edges of the body are not so scary...

What kind of poverty is this chipboard-MDF? Maybe straight from solid oak, but thicker!? Don't rush to insert the speaker into the first hollow you see. Contrary to expectations array valuable wood does not enrich the sound in proportion to the money invested; moreover, it even requires additional damping compared to cheaper materials. Although its undoubted advantages are the ease of finishing: if the acoustics are assembled carefully, bringing it to a nice eco-look will not be difficult. Instead of increasing the thickness, it is recommended to add (glue) another sheet of less resonant material on the back side, for example, the same MDF, to make a “sandwich”. The most successful option for using the array is in shield-type acoustics, where a beautiful and heavy front panel is required.

Exotic. Often the choice is determined by what is at hand. Just as a bird can masterfully weave all kinds of garbage into its nest, so a music lover drags everything that is in bad shape. You can find on the Internet ideas embodied in plumbing pipes, artificial stone, papier-mâché, cases and cases for musical instruments, primitive building materials, IKEA products, etc., etc.

Where should I put the speaker?

The main task of acoustic design can be formulated in simple language approximately like this: to maximally separate the vibrations emitted by the front side of the speaker diffuser from the same anti-phase vibrations emitted by the rear side of the diffuser. From the point of view of the textbook, the ideal acoustic design is considered to be an infinite screen, such an incredibly huge shield in which the speaker is installed. It’s clear that the words “incredibly huge” do not apply to our home or our salary, so engineers began to look for a way to “collapse” this screen with minimal negative consequences for the sound. This is how all the variety of options turned out, some have gained the most widespread fame on the Internet, and we will consider them in this article.

Just a speaker or housing without housing

It’s hard to imagine that there is such a type of “acoustics”, but, scrolling through the feed of photos on Pinterest on the topic of audio, I increasingly come across clusters of 12-inch speakers that are assembled together without any design and clearly represent a complete unit. Probably, the author’s intention is permeated with the following logic: any housing spoils the sound, an acoustic short circuit is better than wooden shackles, but in order to have at least some kind of “low”, you need to take speakers with the maximum cone area for which you can only afford enough money. If this is your path - no comments.

Shield and “broadband”

They say that those who have tried the tube, full-range speaker and open design will never return to the traditional, transistor-rubber lifestyle. Describing the properties of a shield is not a rewarding task; all the necessary information is in the archive, and for the laziest - on YouTube, where they explain in detail what kind of animal it is and what it is eaten with, for example:

The biggest advantage of this design is its ease of manufacture. You need a sheet of your favorite material and a jigsaw. The most important criterion that will influence the final sound quality is the cost of the installed dynamic head. The 4a32 speaker has gained unabated popular fame, even such grandees as fostex, sonido, supravox, sica or the visaton B200 itself are left far behind. The saying “size matters” is the best mathematical formula for a shield (the bigger the better). Next come variations of the shield, for example, a shield with folded side walls, a shield in which the low-frequency module is made in the form of a box with a bass reflex, etc. The signature feature of the sound is an “airy” sound with a minimum of resonances, and at the same time a relatively high sound pressure.

PAS – acoustic resistance panel

What if you try to cross a shield and a closed box? You will get a box with a back wall in which many holes are made. The number of holes, their total area in combination with the volume of the box will determine the degree of damping (resistance), the level of low frequencies (the fewer “holes” - the more bass, but also the more “mumbling”). The quantity is selected experimentally, according to taste.

Linear array of emitters, group emitter (GI)

In fact, this subtype of acoustics concerns more the speakers than the design of the cabinet itself. I think you’ve already seen speakers, each of which consists of a large number of identical small, small speakers, or not very small ones, as your budget and living space allow:

By electrical diagram, the heads are connected in series, that is, the “plus” of the previous one is connected to the “minus” of the next one, it is possible to combine a series-parallel connection. The number of speakers, in fact, is also limited only by money; common sense, as a rule, by this moment disappears without a trace. Don’t think anything bad about me, I tried such a perversion, I even liked it, if possible, I strongly recommend collecting it for yourself similar design at least for the sake of interest. Again, the budget for this outrage is not very large; as a rule, domestic speakers in good condition are used, 5gdsh, 8gdsh, 4gd-8e, etc.

Acoustic design - the same shield or closed box, preferably of a tricky shape, for example triangular. One of the problems to be faced is the high total resistance; not every amplifier will reveal the potential of the “array”. Serial samples produced at the factory have more complex solutions; speakers are often assembled into clever modules, and filters are added.

Bass reflex,bassreflexport, Helmholtz resonator, also known as a box with a “pipe”

Here it is - the most popular acoustic design option. The most favorable price/result ratio becomes widespread; our case is no exception for of this rule. For those who haven’t downloaded the archive of an unknown audiophile, we’ll explain it in layman’s terms. There is a certain volume of air in the bass reflex pipe, which depends on its length; it is also “connected” with the air contained inside the speaker. With successful adjustment of the pipe length (let's not dive into theory right away), it is possible to achieve more confident reproduction of low frequencies than just in a closed box. To put it even simpler, with a bass reflex you get deep bass. For a more in-depth understanding, here is a video from a channel we already love:

Though this type acoustics and popular, it is far from being so easy to manufacture, one thing leads to another. Speakers that are suitable for this design are called “compression”, most often have a rubber surround and a frequency band that requires the installation of a high-frequency link, tweeter or tweeter, that is, an electrical filter is added. The choice of the optimal housing volume, its geometry, and precise adjustment of the pipe length are of great importance and do not always correspond to the calculated values. The situation is made easier by the presence of a mass of projects on the Internet, where the authors have already gone through the thorny path and offer step-by-step instructions with a detailed description of what, how, and what to do. However, there are always enthusiasts who are not satisfied with what is “ready-made” and have the tenacity to go their own way. The disadvantages of the bass reflex are “mumbling” and “crushed middle”. The first is solved by careful selection of the shape, diameter, material and length of the pipe; the second is by adding a separate mid-frequency section. The right path to three-way acoustics.

Reverse hornTQWP and other labyrinths of fate

What people haven’t come up with to complicate the path of vibrations coming from the back of the speaker... Perhaps the company that distinguished itself most of all was B&W with its Nautilus, at least erect a monument to this mutant sea shell. But these are grandees, and all we, ordinary audiophiles, can do is remember our nightmares and place boards with nails inside the rectangular box so that this vile sound doesn’t seem enough. Seriously though, there are speakers for which the “bass reflex” type design does not suit, and the shield does not provide the desired amount of bass, and the sight of the subwoofer makes something clench in your stomach. Then a reverse horn or a more complex option - a labyrinth - comes to the rescue. For those who are interested in how it works, we wish you pleasant viewing.

Someone may object: a reverse horn is not exactly a labyrinth, we can partly agree, but what is more reliable is that it is closer to labyrinths than a classic horn:

It reminds me of an old gramophone. As you can guess from the name, a reverse horn or labyrinth is far from the simplest type of acoustic design; it requires a good understanding of the theory, accurate calculations, or at least compliance with factory recommendations. For example, large manufacturers of wideband speakers, as a rule, provide a couple of variants of housing drawings in the documentation for their speakers.

Onken, closed box (CB), horn, passive radiator and others

Our narrative follows in the footsteps of popular popularity, and this is a rather narrow list. A closed box almost always mumbles, it’s difficult to find a speaker for the onken, the horn is large in size, difficult to manufacture and calculate, the passive radiator works well, but for some reason it has not taken root in amateur designs. You can probably find several more rare types or subtypes of design that are not mentioned here, but what can you do, you can’t cover everything.

Damping, "stuffing", "plug"

The cases are ready, what to do with them next? That's right, damping. Damping can be divided into two types: vibration absorption and sound absorption. Automotive materials, mastics and special sheets with an adhesive layer are well suited for vibration absorption, the latter being preferable. With sound absorption there is confusion and swaying, some people like felt, others like wool, batting, padding polyester, etc. The answer is quite simple - for different effects, depending on the type of housing and the frequency that you want to suppress, the choice of material will depend. Filling the case with sound-absorbing material increases its virtual volume, however, in my opinion, it is impossible to determine a universal norm.

Setting up a crossover (crossover filter)

You decided to make multi-band acoustics. Is a measuring microphone necessary? If this is a one-time project, then no, it is not necessary, it is enough to have a test selection of tracks and some experience to understand which sound can be called more correct. You’ll just have to go through the details of the passive filter longer, listen and compare, but in the end the result will be exactly what your ears and the room need. The situation is a little easier with active crossovers. Previously, you had to make them yourself, etching and routing boards, soldering, a very tedious process, especially if the circuit has a decent slope of cut and adjustment, for three-way acoustics it’s just a wild thing. Fortunately, today you just need to go to ebay and choose an option that suits your budget, whether you want it on op-amps or on DSP. You can smoothly adjust the frequency, and sometimes the slope of the cutoff (in especially rare cases, the phase), even every day.

The final

Sometimes it seems to me that the situation in the audio world is reminiscent of the legend of the Tower of Babel. Once upon a time, in distant times, when Van Den Hul's foot had not yet set foot on the ground, people built together one set of home stereos. Large, large speakers, an equally large amplifier, and thick, thick cables stretched to them. Someone from above saw this and was horrified - what a joke, if only they had read some books... Severe punishment befell the unlucky audiophiles, since then they have been arguing until they are hoarse, but they still cannot agree on how to make amplifier speakers, so everyone makes their own , how can.

Study the design of the speaker system. Although the underlying technology hasn't changed much since 1924, audio technicians have been improving the design, electronics, and sound of loudspeaker systems throughout that time. However, all speaker systems consist of several basic components:

Purchase a speaker system assembly kit. Of course, you can purchase all the components separately, but it is very difficult to build a good speaker system unless you have spent years studying the principles of sound and electricity. However, the novice DIY speaker enthusiast has another option - purchasing a pre-designed speaker kit with speakers, crossover filters and enclosures. When looking for a good speaker kit, consider the following:

Solder the parts of the separation filter according to the diagram provided. You will need a soldering iron, hot glue, and a circuit diagram to make sure the decoupler works correctly. All kits for self-assembly of a speaker system include illustrations with a diagram of the connection of all components, and if you are creating a system from scratch, then examples can be easily found by searching the Internet. This will prevent your speaker system from shorting or burning out.

• Before proceeding, make sure you fully understand how to read electronic circuits.
• Once the pieces are soldered, secure them using a glue gun or cable ties to a small panel.
• Finish the assembly by connecting the crossover wires to the speakers using speaker cable.