Speakers are an acoustic system and they come in a variety of sizes. From a huge music center to a portable small speaker powered by batteries. This device is quite simple and can be assembled at home.
Speakers usually consist of several speakers, which, in turn, consist of several magnets (usually two). The operation of the magnets is controlled by an amplifier that operates at audio frequencies.
Speakers are divided into two types: passive and active. In passive devices, the amplifying element does not require additional power. The simplest passive system is regular headphones. Active devices require additional power to function.
In order to assemble a speaker system for a PC, you will need:
REFERENCE. Instead of a digital amplifier, you can also use an analog one on transistors, but then you have to use the DAC, and the selection of the necessary digital-to-analog converter is a rather long thing that requires special calculations. At its core, the RAM 8403 is an ADC amplifier that makes it easy to assemble homemade speakers.
You will also need tools:
In order to provide the highest quality sound, it is necessary to make a spacious and closed case so that air circulates in it. This will make the sound deeper and richer.
For the case, chipboard, fiberboard or plywood will go. You can also use textolite or OSB. You should not choose too thick plates, as this will make the structure too heavy.
In order for the speakers to fit, you need to correctly measure the diameter and circumference, and then cut the holes on the front panel.
ATTENTION. Attention should be paid to the fixation, since the speaker cabinet is often affected by vibrations. In addition to glue, it is better to use corners on self-tapping screws. So the design will turn out more reliable and last longer, and it will also be possible to disassemble the device and then assemble it.
On the rear panel, you should cut in places for the power cable, connection cable and a separate connector for the power toggle switch.
There are several basic options for creating a power supply in a circuit. If the amplifier is a complex device with an ADC and an adapter (like the RAM 8403, for example), then it can be powered from a simple USB. This makes it easier to interact and work with the PC. If there is a separate power supply, then you should carefully consider the choice of components, according to consumption and output power.
ATTENTION. All wires and cables must be chosen to the optimal length, as too long wires can interfere and cause inconvenience. In this case, the cables should easily reach all the necessary connectors. The optimal length of mini Jack and USB wires ranges from 1 to 5 meters.
To assemble a home speaker system, the loudspeakers (speakers) are connected to an amplifier and a connector. The mini-jack plug has three channels (left, right and common). They are separated by black stripes on the connector itself and are mirrored from the middle.
On the board itself there are connectors for the wire (L-Left G-Central R-Right). Following the order, you should connect the mini-Jack connector with the amplifier board with wires.
Then, observing the polarity, the speakers should be connected to the amplifier. Speaker locations on the device are referred to as Rout and Lout.
IMPORTANT. Be aware of polarity when connecting speakers.
This device will be powered via USB, since 5 volts is enough for the amplifier. When soldering the power cable, you should also remember about the polarity. It is also important not to forget to bring the toggle switch from the power supply of the speaker through one of the wires, otherwise the device will be powered every time it is connected via USB.
After all the parts are assembled, you should use heat shrink at the folds, namely on the mini Jack, the power switch and the wires that connect to the speakers.
After the main device is assembled, it should be placed in the case assembled earlier. Assemble the speakers carefully, as there is a risk of damaging the wires or the connector.
ATTENTION. The RAM 8403 has a gain control knob. It should be displayed on the front or side panel of the device.
Sometimes, to improve the sound quality, the front panel (where the speakers go) is covered with fabric.
One day I decided to assemble high-quality acoustics for sounding a small room, as well as for use as near-field monitors when working with sound on a computer (hobby). The main requirement is an adequate sound in relation to the source. Not so that “the bottoms are sausage” or “cymbals rang”, but an adequate natural sound. So, we collect high-quality "shelf speakers".
In theory, the ideal system is single-lane. But, like everything ideal, such a system does not exist in nature. Yes, the same Vizaton has very high-quality broadband speakers, but for some reason all well-known manufacturers make two-way shelf systems. And when it comes to the floor version, then 3 stripes are not uncommon. There was no particular question here - the classic two-band version: bass and treble.
The main requirement for speakers is an optimal price / quality ratio. Those. it should not be "cheap" for 500 rubles, but not a mind-blowing "high-end" for $1000. Besides, I wasn't in a hurry. The idea to assemble “shelf speakers” with my own hands came a long time ago, and I threw the bait in advance to my good friend, the “sick” sound, with whom we have been constantly and fruitfully communicating on this topic for a long time.
The first to appear were HF - Vifa XT19SD-00/04 ring-rad. These are high quality 4 ohm tweeters, quite popular among audiophiles. They were planned for one set, but for some reason they did not go and ended up in my set.
LF arrived second. They turned out to be very decent midbasses from the Soundstream Exact 5.3 kit. Here you can read a little about them. It so happened that the “tweeters” burned out during installation, and the lone woofers were not needed by themselves. 4-ohm 5.5" midbasses, mounted in a die-cast aluminum basket, were immediately purchased.
Now that you have speakers, you can start creating acoustics.
Each option has its pros and cons. First, you need to take into account the compactness of the speakers themselves and the associated difficulties in layout in a limited space. And it makes no sense to mount outside. Secondly, individual modules as independent components can be combined in the future, and it is also easier to repair if something happens. And thirdly, active speakers are quite expensive. Because if you make a decent amplifier (and sometimes one in each case), then it will turn out to be more expensive than the acoustics themselves. Besides, I already had an amplifier. But in any case, I am for the scheme - passive acoustics + amplifier, it is more versatile.
We have decided on the speakers, now we need to understand which case is optimal for them. Dimensions are calculated based on the sound characteristics of the woofer. There are no recommendations on the manufacturer's website, because. The speaker was intended primarily for car audio. There is no point in keeping special equipment for these purposes, unless it is your job. Therefore, an intelligent dude with a special stand comes to the rescue. As a result of laboratory tests, we obtain the estimated case size of 310 x 210 x 270 mm. During the measurements, the parameters of the phase inverter were also calculated.
By the way, many manufacturers publish recommended cabinet sizes for speakers on their websites. When such information is available, it is logical to use it, but in this case I did not have such data, so I had to do laboratory research.
In my opinion, the most optimal material for the case is MDF. It is acoustically neutral and also slightly better in performance than chipboard. Plywood is also good, but quality plywood is not easy to find and is more expensive and harder to work with. A 22mm MDF sheet was chosen as the starting material for the body. In principle, the standard 18-20mm is enough, but I decided to do a little with a margin. There is no such thing as too much rigidity.
One of the most important steps. Before going for MDF, I advise you to decide on the design in order to immediately ask the seller to cut the sheet in parts, and at a normal point of sale there are always good machines with accurate and even cuts. At home, such a cut is difficult to obtain.
So, design. The speakers should look at least as good as the "industrial" ones, so that there is no feeling of a club of crazy hands. After all, we make not only high-quality, but also beautiful acoustics. In general, there are practically no beautiful, interesting and at the same time structurally simple acoustic systems. Beautiful acoustics are made by the Italian Sonus Faber, stunning in beauty - Magico Mini. But they are all made using precision machines, which, by definition, are not at home. Alternatively, you can order cases to a good "cabinet maker" with hands and CNC. Such work will cost, depending on where and what you order, from 10,000 rubles. up to 30 000 rub. along with materials. If the specialist is good, then the columns will look no worse, or even better than the “store” ones. In this case, I decided that I would do everything myself. Therefore, we look at things realistically and make a design without any bevels, curly cuts, etc. Those. it will be a parallelepiped. The calculated dimensions give a rather pleasant proportion, and the proportion in design is already half the battle.
What to design? Although I am connected with design by occupation, I know 3D packages, to put it mildly, superficially. At the same time, the program should be more engineering than rendering. Specialized "Kadas" for this purpose are too heavy and unnecessary. The solution was quickly found - freeware SketchUp is more than suitable for this purpose. It is so simple and intuitive that it was fully mastered in about an hour. He can do the main thing: quickly create any shapes, set dimensions, use simple textures. I think that such a program is ideal for "home" purposes. In it, you can easily, for example, design a kitchen or even a small house.
Here is the body structure:
The design is simple. Six walls glued together. Front 2 cutouts for speakers. There are 2 cutouts at the back: for a phase inverter and for a terminal block. A 120x80 rectangle indicates a place for a crossover. Inside, the phase inverter is another wall in the width of the internal space, attached perpendicularly under the cutout:
Based on the drawing, a diagram of cutting the sheet emerges:
How will we finish the body? Pasting with a film was immediately excluded - the acoustics should look decent. Painting was considered as an option. I abandoned this idea, because. such columns will not fit into every interior (at least they did not fit into the current one). I want more versatility. In this regard, natural veneer is more suitable. But acoustics completely glued with veneer looks boring. Finding a combined solution:
In general, the options are not bad in appearance, but purely constructively cause difficulties. As a result, it was decided to trim the side walls with ash veneer, and cover the remaining 4 walls around the circumference with leather, or rather with high-quality automotive leatherette. The pishchal is beautiful in itself, but the woofer has a constructive overlay on the front side of the case, which will not look very nice. Therefore, it was decided to make an additional decorative overlay (ring) for it, which will press it to the body, and at the same time add beauty to the column itself. We decided on the design and construction.
Before moving on to the next step, I will outline what basic tools are needed for the job:
- Circular.
- Electric jigsaw.
- Drill.
- Frazier.
- Grinder.
- Straight arms.
Without this set, it is better to order cases from a good craftsman.
So, we cut the budget sheet of MDF. I already wrote that it is better to saw on special machines - it's inexpensive, but it turns out exactly. But since I decided to make the case myself inside and out, then for the purity of the experiment I sawed it myself with a manual circular saw, and small pieces with a jigsaw with a guide. As expected, the perfect cut did not work. After cutting, pairs of walls (left-right, front-back, etc.) are installed in pairs, adjusted with a grinder and / or an electric planer and checked for perpendicularity with a square. And in the future, during assembly, they are finally adjusted after gluing. Loss of 2-3 mm is insignificant. But still, I recommend sawing immediately “at the base”, save a lot of time.
The walls are glued with PVA and tightened with screws. First, we glue the case without the front wall.
Now there is a hole for the terminal block, as well as a chamfer in order to “drown” it. Initially, according to the project, the terminal block was supposed to be placed below. But in the process, it became clear that mounting the crossover in the center through the hole for the woofer would not be very convenient, so I moved the hole for the terminal block higher, and the place for the crossover lower.
Before you “attach the lid”, you need to glue the insides with vibration-proof material.
You can close the box.
Now one of the very important stages is cutting holes for the speakers on the front panel. I have already said that the ideal speaker system is single-way. Why? Because the propagation of sound goes from one source to the listener without a mismatch in time due to the difference (negligible) in the distance, which is when using a multi-band system. Therefore, the speakers are best placed as close to each other as possible. So the sound picture is "dense". We calculate the holes so that the distance between the edges of the speakers will be approximately 1 cm. The holes are sawn with a jigsaw with a circular guide.
Speakers must be recessed. We apply the speakers and along their edge we outline the diameter for chamfering. The depth of the chamfer is measured by the overlay of each speaker. The chamfer was removed with a manual milling cutter. The depth of cut was set at the stop. No guides were used, layer by layer was carefully removed in a circle to the line. For "squeaking" two "ears" were additionally cut out for the terminals.
After the chamfers are removed, we apply the terminal block and speakers, after which we drill holes for future self-tapping screws with a thin drill. Without them, firstly, the MDF itself can “spread out” when screwing in the screws, and secondly, it will be more difficult to place the speakers evenly during the final installation. For a very long time I thought about how to set the speakers relative to each other, I came to this scheme:
Screw holes on exterior surfaces must be repaired before final finishing. I used epoxy. In order not to wait until one surface hardens, I sealed each surface with adhesive tape and took on the next. When the epoxy was dry, I went through the grinder.
The veneer was left from some ancient times, so I didn’t have to buy it. The sheets were not wide, so a couple of sheets were selected, fastened with adhesive tape and glued to the body. First one side, then the other.
The veneer needs to be protected. I covered it with clear yacht varnish.
Now you need to fit the body with leatherette. There are many options for how to do this. I decided to do the following. A strip is cut 20 mm larger than the body width and slightly longer than the body circumference. On each side it is folded by 10 mm, the hem is glued to the "special glue 88". Then, on the same glue, the strip is glued around the circumference to the body. First the bottom (partially), then the back wall, then the top, then the front and again the bottom. At the last stage, before gluing, the strip is cut in place and glued end-to-end. I glued all sides at once, i.e. didn't wait for each side to dry. After each side, I took a short pause (the glue sticks quickly enough), and started on the next one.
After everything is dry, the skin is carefully cut and glued inside on the opening of the phase inverter.
If you really want to, then you can somehow ennoble the fazik.
Then holes are cut on the terminal block, "woofer" and "tweeter". The skin on the terminal block and HF will sink down, so the cutout diameter can be left 5-10 mm smaller. The skin on the bass will be pressed by a decorative ring, so you need to cut it so that it is not visible.
First of all, we mount the crossover. Cross - self-made, on a good elemental base. Air core coils, tweeter film capacitors and MOX resistors are used. I didn’t solder it myself, but I ordered sensible guys.
By the way, many manufacturers sin by the fact that sometimes they put not very good crosses into even rather expensive acoustics. On the Internet, you can find many “gutted” systems on this topic. Before mounting the cross, you need to solder three pairs of wires: for the terminal block, LF and HF. It turned out that it would be necessary to mount directly on a plate with vibration isolation. He considered that it was superfluous and dismantled it. Now you can screw. As a substrate, I used a piece of packaging film from under some kind of device.
Now we solder the desired pair of wires to the terminal block and fix it on the case. The terminal block and speakers are screwed with decorative black self-tapping screws with an asterisk head. The overlay on the “squeaks” is screwed with similar self-tapping screws, so it would be logical to use the same for the rest. The back wall is ready.
Before mounting the speakers, it is necessary to dampen the case with a special padding polyester. For these purposes, Visaton cotton wool was used. The synthetic winterizer is glued along the circumference along the walls.
With what dynamics to start, in principle, it does not matter. I started with the squeak. We solder the corresponding pair of wires from the cross, insert the speaker and fasten it with screws. Ready.
Midbass must be slipped under the skin, and pressed down with a decorative ring from above. Solder the remaining pair of wires and mount the speaker.
All? All. We fasten the speaker cable to the terminal block and begin testing.
The system was tested in the following configurations:
1. Receiver Sherwood VR-758R + acoustics.
2. Computer + Unicorn (USB-DAC) + Self-made stereo amplifier + acoustics.
3. Computer + E-mu 0204 (USB-DAC) + Sherwood VR-758R + acoustics.
A little about the configurations themselves. I personally think that at the moment the ideal option for a home music center is: computer + USB-DAC + amplifier + acoustics. The sound in the digital without distortion is removed via USB and fed to a high-quality DAC, from which it is transmitted to a high-quality amplifier and then to acoustics. In such a chain, the amount of distortion is minimal. In addition, you can use completely different backing tracks: 44000/16, 48000/24, 96000/24, etc. Everything is limited by the capabilities of the driver and DAC. Receivers in this regard are less flexible and obsolete in advance. The size of modern hard drives allows you to store almost the entire media library on them. And the tendency to subscribe to Internet content may abolish this option, although this is not the near future and is far from suitable for everyone.
I will say right away that in all three configurations the acoustics sounded great. To be honest, I didn't even expect it. Here are some subjective aspects.
1. Adequate and natural sound. What is recorded is reproduced. There are no twists in any direction. As I wanted.
2. Greater sensitivity to the source material. All flaws in the sound recording, if any, are clearly audible. High-quality mixed tracks listen perfectly.
3. Well-readable basses for such sizes. Of course, you can't fully appreciate organ music on bookshelves (it's hard to appreciate it on acoustics in general), but most of the material can be "digested" without problems. It is difficult to expect more from such babies.
4. Very good detail work. Every instrument is heard. Even with a rich sound image and a decent volume, the sound does not go into mush (the amplifier plays an important role here).
5. I want to make it louder;) Ie. acoustics does not yell, but plays smoothly. Although there is also no small merit of the amplifier itself, because. as the load increases, a good amplifier maintains linearity.
6. From long listening does not hurt the head. For me personally, this often happens, but here he plays all day and at least something.
7. Fears about the incorrect panorama and strong dependence of the sound on the position of the listener were not confirmed. As far as I know, car acoustics have a specific sound phasing due to the location of the speakers in the cabin. Namely, I read about this kit that its midbasses are more universal in this regard. Which is actually confirmed. You can sit in the center in front of the speakers, you can stand next to them sideways - the sound is excellent. There is a relationship, but it is very small.
As for the configurations themselves, the best sound quality was achieved with the second configuration.
First, a very high quality Unicorn DAC was used. you can read about it.
Secondly, the "self-made amplifier" is the know-how of one sensible Togliatti "sound player". Here it is in a nice little aluminum case:
And here is the "gutted" one:
In a nutshell, we managed to find a circuit solution in which the amplifier retains its characteristics when the volume changes, i.e. does not distort the sound at any (structurally permissible) volume. A lot of amplifiers (even very expensive ones) suffer from this. It was amazing to listen to how such an amplifier brought many loudspeakers to life, i.e. made them sound like they should sound. By the way, some industrial amplifiers were also redesigned according to this scheme (in particular, quite good Xindak itself), and they had a “second wind”.
Compare acoustics with something else, you ask? Yes, for example, with the ProAC Studio 110, these are quite high-quality bookshelf acoustics, here's a little about them. Compared, realized that they sound exactly no worse. The “proaks” may have a slightly lesser dependence of the sound on the position of the listener due to the specific placement of the inverter and the “tweeter”, where they somehow cleverly calculated all this. And the rest is absolutely no worse, even I personally liked my homemade products more, but we’ll write it down to subjectivity;) I also put on headphones (quite good Koss) and compared by panorama, tops and bottoms. Absolutely identical sound. Even downstairs. In general, the delight is complete.
Mid/bass speakers (pair): 3 000 rub.
Tweeters (pair): 3 000 rub.
Crossover (pair): 3 000 rub.
Sintepon: 160 rub.
Terminal (terminal block): 700 rub.
Screws: 80r.
MDF sheet, 22mm: 2 750r.
Scotch tape: 30 rub.
PVA: 120 rub.
Special glue 88: 120 rub.
Vibration isolation: 200 rub.
Figured ring-lining: 500 rub.
Cable: 500r.
Total: 14 160 rubles.
Some materials were or got free of charge, respectively, are not taken into account here.
In any more or less complex device or complete functional system, absolutely everything is important. When it comes to a musical system, a large number of factors influence the final result:
Soundtrack quality.
- A device for playing a phonogram.
- Digital-to-analogue converter.
- Signal amplifier.
- Wires.
- Speakers installed in the speaker cabinet.
- Properly designed for speakers and high-quality assembled cases.
- Scheme and kit for the crossover.
This is a basic but not complete list.
It is wrong to assume that the main thing is the amplifier or the main thing is the wires, or the main thing is the speakers. A home music system is like an orchestra. And if in this orchestra someone will be bad, and someone will play brilliantly, then in general it will turn out - average. Or, as a very precise example said: if you mix a barrel of shit with a barrel of jam, you get two barrels of shit.
There is another extreme. A good system costs fabulous money. So each component should cost half a million. And phonograms should be exclusively in Super Audio CD or on branded records. Like a closed society of elite audiophiles. Bullshit is everything.
I came to the conclusion that it is quite possible to assemble our own relatively budgetary system, which is described in one word “Sounds”. And if as a DAC or amplifier, due to its peculiarities, it is better to use real-life solutions, which are now very numerous. Then a properly made (independently or on order) speaker system will sound better than a “branded” one purchased for the same money. Almost all components can now be ordered online. Moreover, many manufacturers publish enclosure diagrams for the corresponding speakers. There is a lot of software for calculating the parameters of cases. There are many specialized forums on the network, and offline there are people with hands. Of course, it is impossible to be an expert in everything. As in any field, the main thing is to know the general principles.
The article does not claim to be the ultimate truth, but I hope that my thoughts and my experience will be useful to someone else.
Upd. In the comments, many people ask about the amplifier. If anyone is interested, write in a personal, I will give the coordinates.
At first glance, making your own speakers is quite simple. However, this is misleading. First of all, it should be noted that the models are made with various elements. Depending on them, the device parameters and sound quality will be different.
There are special requirements for computer speakers. You can also make a model for a car or a studio yourself. In this case, it is very important to follow the instructions. First of all, to assemble the speakers, you should consider the standard scheme of the model.
The speaker layout includes speakers, overlays, a diffuser and a crossover. Powerful models use a special phase inverter. Amplifiers can be installed with field-effect or switching transistors. Capacitors are used to improve sound quality. The woofer is selected with an amplifier. The dynamic head must be attached to the seal.
Single speaker speakers are very common. To assemble the model, you will first have to deal with the case. For this purpose, plywood is often used. At the end of the work, it will have to be sheathed. However, the first step is to make side racks. For this purpose, you will have to use a jigsaw. you can pick up a small power.
The inner side of the plywood is necessarily stitched with a vibration-proof tape. After fixing the speaker, the seal is fixed. For this purpose, glue is used. Next, it remains only to attach the diffuser. Some make a separate shelf for it and fix it with stacking screws. To connect the speaker to the plug, a terminal block is installed. How to enable speakers? For this purpose, a cable from the terminal block is used, which should lead to a power source.
Speakers for two speakers can be made for home or car. If we consider the first option, then the diffuser will need an impulse type. First of all, strong plywood is selected for assembly. The next step is to cut out the bottom rack. Models with legs are very rare. To cover the veneer, you can use ordinary varnish. Vibration isolation tape on the front pillar does not need to be glued. The diffuser is attached under the speaker. To make a hole in the panel, you need to use a jigsaw. The phase inverter is fixed at the rear wall. Some make devices with horizontal speakers. In this case, the diffuser will be at the top of the structure. The speaker wires are of the two-wire type.
Speakers (homemade) with three speakers are very rare. These devices are most suitable for multi-channel type. To assemble the model, first of all, sheets of plywood are selected. Some also advise using veneers. However, natural wood models are quite expensive on the market. Speakers should be installed in a horizontal position. Also, the device will need an amplifier.
For its fixation, metal corners are used. To connect the plates, you will need lag screws. In some cases, the plates are attached with glue. Next, the model will have to be partially covered with leatherette. The next step is to install the terminal block. In order to fix it on the case, you will need to make a separate hole. It is also important to note with regulators. Microcircuits for them are used capacitor type. When the speakers are phoning, you need to change the diffuser.
Studio speaker drawings involve the use of powerful speakers. The diffuser is most often used of the impulse type. Many experts recommend installing two amplifiers. For normal operation, a zener diode is required.
For the purpose of self-assembly of the speakers, the case is first made. Round holes are made on the front panel for the speakers. You will also need a separate output for the phase inverter. The layout of the columns is quite different. Some prefer to varnish the surface of the case. However, there are models covered with leather.
Speakers for computers are often made on one speaker. To assemble the model, veneer sheets of small thickness are selected. A hole for the speaker is cut out on the front panel. The phase inverter should be located at the rear of the case. If we consider low power models, then the amplifier can be used without a resistor.
In order to adjust the volume of the speakers, special crossovers are used. These elements are allowed to be installed on a phase inverter. If we consider devices with a power of more than 100 W, then amplifiers can only be taken with resistors. Some select impulse diffusers for the model. At the end of the work, a terminal block is always installed.
Available for two or three speakers. For self-assembly of the model, you will need sheets of plywood. In some cases, varnished veneer is used. To fix the speaker, you need to make a hole in the panel. The next step is to install a phase inverter. Some modifications are made with low-frequency cores. If we consider speakers (home-made) of low power, then the phase inverter can be installed without an amplifier.
In this case, a multi-channel crossover is used to adjust the sound. Some specialists install terminal blocks behind the phase inverter. If we consider speakers with a power of more than 50 W, then the microcircuits are used for two amplifiers. The diffuser is installed as standard with an impulse type. Before fastening the case, it is important to take care of the vibration isolation layer. For the terminal block on the plate, you need to make a separate hole. Some believe that the body must be cleaned without fail. Speaker wires are suitable for two-wire type.
Portable speakers with an open case are quite simple to make. Most often they are made with one speaker. Holes are made on the back of the device with a drill. The plates are connected directly with lag screws. The diffuser for such devices is suitable for a pulsed type. Phase inverters are often installed with a single amplifier. If we consider powerful portable speakers, then they use a resistor crossover. It is attached to the phase inverter. Many experts recommend installing speakers on a seal.
Speakers (homemade) with a closed case are considered the most common. Many experts believe that they are the best in terms of sound quality. Phase inverters for devices are suitable for operational type. Woofers are installed in holes. For the purpose of assembling the case, ordinary sheets of plywood are suitable. It is also important to note that there are modifications with cores. If we consider high-power speakers, then the terminal blocks are installed at the bottom of the case. The design of the model is quite different.
Assembling 20 V speakers is quite simple. First of all, experts recommend preparing six sheets of veneer. They should be varnished at the end of the work. It is more expedient to start the assembly with the installation of speakers. The phase inverter is used pulse type. In some cases, it is installed on linings. Also, experts recommend lining rubber seals.
The speakers are powered through the terminal block. It attaches to the back panel. The phase inverter can be installed with or without an amplifier. If we consider the first option, then the cores are selected of the phase type. In this case, the woofer can not be used. If we consider speakers without an amplifier, then they use a crossover. At the end of the work, it is important to clean the body and varnish it.
Speakers (homemade) at 50 watts are suitable for conventional acoustic players. In this case, the body can be made from ordinary plywood. Many experts also recommend using natural wood veneer. However, it is important to note that he is afraid of high humidity.
After choosing the material, you should deal with the speakers. They must be installed next to the phase inverter. In this case, an amplifier is indispensable. Many experts recommend selecting only low-frequency crossovers. If we consider modifications with a regulator, then they use an impulse diffuser. The terminal block in this case is installed last. You can always use leatherette to decorate the speakers. A simpler option is to cover the surface with varnish.
Columns of 100 W are suitable for powerful ones. In this case, the phase inverter is taken only as a pulsed type. It is also important to note that the amplifier is installed with a crossover. Many experts recommend using veneer to assemble the case. It is more expedient to install the woofer on a lining.
I want to tell you about the Sony neodymium dynamic heads I purchased, made in Vietnam. The Vietnamese are generally great - they make very high-quality things, I always give preference to them when shopping. Who does not know, neodymium is a magnet that is lightweight and powerful, which is especially important for manufacturers of home acoustics. In voice coils, neodymium is responsible for the transmission of the frequency range, and therefore for the purity of the sound and its saturation. All these qualities are present in my speakers, which cost me only 750 rubles. - the truth on the action, as the last product. The declared peak power of these 3.5 inch loudspeakers is up to 200 watts :-) In Russia, as far as I know, the power differs from both China and Western manufacturers. However, with a 2 x 50 watt amplifier they work perfectly.
So, the goal was to make a homemade cabinet for them that would provide maximum bass transmission and differ in minimum dimensions, so all these abstruse Internet programs for calculating the speaker cabinet would not suit me.
I designed the speaker cabinet in such a way that the sound bounces off the cabinet wall and then off the magnet and exits through a fairly large bass reflex.
Believe it or not, the bass is quite impressive at this size (h,w,d - 115 x 115 x 130 mm.). In order to avoid the unnecessary effect of "knocking on a piece of wood", I glued the inner walls of the case with mineral wool.
After everything was done, it remained to attach the legs to the new speakers, and since they are homemade, I also decided to make the legs myself, and not buy them.
I made oval-shaped recesses in the plasticine, filled it with epoxy glue and, after hardening, leveled it with a file in height. I thought to put an LED in each leg - it would be very unusual, but these are an extra pair of wires, in general, I didn’t.
These speakers serve as computer speakers for me, but they can be used as rear speakers in a cinema or if put together (they fit perfectly in size) - you get a front speaker. That's all, see what happened in the photo. Especially for - Valery K.
Discuss the article SIMPLE HOME-MADE ACOUSTIC SPEAKERS
Before a detailed consideration of the problem, let's outline the range of tasks, knowing the ultimate goal, it will be easier to choose the right direction. Making speaker systems with your own hands is an infrequent case. It is practiced by pros, novice musicians, when store options are not satisfactory. There is a task of embedding in furniture or high-quality listening to existing media. These are typical examples that are solved by a set of generally accepted methods. We will take a look at it. We do not recommend flipping the speaker device diagonally, delve into it!
There is no chance of making a speaker system yourself without understanding the theory. Music lovers should be aware that the biological species Homo Sapiens hears sound vibrations of frequencies from 16-20000 Hz with the inner ear. When it comes to classic masterpieces, the spread is high. The bottom edge is 40 Hz, the top edge is 20,000 Hz (20 kHz). The physical meaning of this fact is that not all speakers are able to reproduce the full spectrum at once. Relatively slow frequencies work better with massive subwoofers, and beeping at the lower border is reproduced by smaller loudspeakers. It is clear that for most people this means nothing. And even if part of the signal is lost, will not be reproduced, no one will notice it.
We believe that those who have set themselves the goal of making an acoustic system on their own 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 band of the audible spectrum. But the subwoofer, even in complex systems, is one. This is due to the fact that low frequencies make the environment vibrate, penetrating even through walls. It becomes unclear where exactly the basses are coming from. Therefore, there is only one bass speaker - a subwoofer. But as for other things, the person will confidently say from which direction this or that special effect came (the ultrasound beam is blocked by the palm of your hand).
In connection with the above, we will divide the acoustic systems:
It is important to create the right enclosure for each speaker. Low frequencies will require a wooden resonator, for the upper end of the range it does not 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 in science, it practically remains to copy finished designs, the topic is devoid of sensible literature.
The scope of tasks is outlined, readers understand that a home-made acoustic system is built with the following elements:
Initially, we select the number of columns, type, location. Obviously, to produce in a larger number than the home theater has channels is an unreasonable tactical move. A cassette recorder needs two speakers. At least six cases will be released for the home theater (there will be more speakers). According to the needs, accessories are built into furniture, the quality of bass reproduction is lame. Now the question of choosing speakers: in the publication of the authorship of Naidenko, Karpov, the nomenclature is given:
They gave the basic principles for designing acoustic systems, proposed an electrical circuit for a filter that cuts the stream 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 repeating ourselves, readers can take the trouble to look through the section, find specific titles.
The next question is the filter. We believe that National Semiconductor will not be offended if we scan the drawing of the Ridiko translation amplifier. The figure shows an active filter powered by +15, -15 volts, 5 of the same type of microcircuits (op-amps), the cutoff frequency of the subranges is calculated by the formula shown in the image (duplicated by text):
P - Pi known to schoolchildren (3.14); R, C - ratings of the resistor, capacitance. In the figure, R \u003d 24 kOhm, C - is hushed up.
Active filter powered by electric current
Given the capabilities of the selected speakers, the reader will be able to choose a parameter. The characteristics of the column 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 transfer coefficient. On the frequency response given in the translation, which we omit, the boundary is 1 kHz. Let's calculate the capacity of the specified case:
C \u003d 1 / 2P Rf \u003d 1/2 x 3.14 x 24000 x 1000 \u003d 6.6 pF.
Not so hot what a large capacity is selected from the condition of the maximum allowable 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. Don't try to put in DC electrolytic capacitors, the circuit has a chance of blowing up. There is no point in looking for the original circuit of the LM833 chip because of Sisyphean labor. Some readers will find a replacement chip that is different ... we hope for understanding.
As for the relatively small capacitance of 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 distortion due to the presence of electrolytic capacitors, coils with a ferromagnetic core. Feel free to move the range division boundary, the total bandwidth remains the same.
Passive filters will assemble with their own hands each trained in soldering, a school physics course. In an extreme case, enlist the help of Gonorovsky, the intricacies of the passage of signals through radio-electronic lines with non-linear properties are nowhere better described. The presented material interested the authors in low and high frequency filters. Those who want to divide the signal into three parts should read the works that reveal the basis of bandpass filters. The maximum allowable (or breakdown) voltage will be scanty, the value will become significant. To match the mentioned electrolytic capacitors 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 powering speakers. Wind the transformer (an example was given, PC program Trans50Hz), supply 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, more accurately correlate the ranges with the filter parameters.
For passive speaker crossovers, you will find many calculators on the Internet (http://ccs.exl.info/calc_cr.html). The initial figures of the calculation program takes the input impedance of the speakers, the division frequency. Enter the data, the robot will quickly supply the capacitance and inductance values. On the given page, set the filter type (Bessel, Butterworth, Linkwitz-Riley). In our opinion, a task for the pros. The active stage shown above is formed by 2nd order Butterworth filters (frequency response reduction rate of 12 dB per octave). It concerns the frequency response (frequency response) of the system, it is clear only to professionals. When in doubt, choose the golden mean. In the literal sense, check the box on the third circle (Bessel).
I happened to watch a video on YouTube: the young man announced that he would make a speaker system with his own hands. The youth is talented: he ruined the speakers of a personal computer - well, none at all - brought into the world God's amplifier with a regulator, placed it in a matchbox (acoustic system case). Computer speakers are notorious for poor bass reproduction. The devices themselves are small, light, and secondly, the bourgeois save materials. Where does bass come from in an acoustic system? The young man took ... read on!
The most expensive component of the music center. Hi-end class acoustics bypasses a cheap apartment in cost. Repair, assembly of speakers is a good business.
The low-frequency amplifier of the speaker system will assemble an advanced radio amateur, no Kulibins are needed. A volume knob sticks out of a matchbox, input on one side, output on the other. The speakers of the old speaker 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 a squeak, the clever boy knocked together inch boards in a box. The speaker of an old acoustic system was placed in the size of a mailbox, shifted, as is done by manufacturers of modern home theater subwoofers. I was too lazy to finish the speaker from the inside with a sound insulator. Those who wish can use batting or other similar material for the speaker system. Small speakers are placed inside oblong boxes, just containing the end of the loudspeaker. The proud lad 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, does not drink in the alley, becoming like his peers, does not spoil future brides in his free time, is busy with business. As one acquaintance said: “The young generation is forgiven for the lack of knowledge and experience, not for the excess of arrogance reinforced by indifference.”
We decided to improve the technique, frankly we hope that the addition will help make the speaker system a little better on its own. Problem? The concept was invented by radio engineers, the creators of acoustic systems - frequency. The vibration of the universe has a frequency. They say that even the human aura is inherent. It is not for nothing that each good speaker can accommodate several speakers. Large ones are for low frequencies, bass; others - for medium and high. Not only the size, but also the device they have is different. We have already discussed this issue and we refer those who are interested to the written reviews, where the classification of acoustic systems is given, the principles of operation of the most popular ones are revealed.
Computer scientists know the BIOS interrupt system buzzer, which seems to be capable of producing a single sound, but talented programmers have written fanciful melodies on it, even with an attempt at digital synthesis and voice reproduction. However, if desired, such a tweeter cannot produce bass.
Why this conversation ... A large speaker should not just be adapted to one of the channels, but bass specialization should be awarded. 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, there is little point in this. At the same time, bass is lost from the same channel, and high frequencies die on a large speaker. How to be? We propose to introduce passive band-pass filters into the circuit, which will help to split the stream into two parts. We take the scheme of a foreign edition for the simple reason that it was the first to catch our eye. Here is a link to the original site chegdomyn.narod.ru. The radio amateur re-shot from the book, we apologize to the author for not indicating the source. This happens for the simple reason that it is not known to us.
So, picture. The words Woofer and Tweeter are immediately evident. 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, and the subwoofer accounts for the low-frequency band. Radio amateurs themselves can calculate the bandwidths using well-known formulas, for comparison, for the first octave, as you know, 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 see the diagram...
Not quite a musical scheme. In the position occupied by the system, the voice is being filtered. Range 300-3000 Hz. The switch is signed Narrow, translated as a stripe. To get Wide (wide) playback, omit the terminals. Music fans can throw away the Narrow bandpass filter, Skype surfers are advised to avoid a hasty decision. The circuit will completely exclude the microphone loop effect, known everywhere: a shrill buzz due to overamplification (positive feedback). A valuable effect, even the military knows the difficulties of using a speakerphone. The owner of the laptop is aware...
To eliminate the feedback effect, study the question, find at what frequency the system resonates, cut off the excess with a filter. Very comfortably. Regarding popular music, we turn off the microphone, take it away from the speakers (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, the diagram depicts (the Narrow band-pass filter is discarded):
Speakers must match. Suggestions for this site. The subwoofer will be MSM 1853, the tweeter (the word was not written off) will be PE 270-175. You can calculate the bandwidth yourself. The capital letter Ω means komas - it's okay, change the denomination. Remember, the capacitances of capacitors connected in parallel add up like series-connected resistors. In case it is difficult to get suitable denominations. It is unlikely that it will be possible to make speakers with your own hands, it is realistic to dial small resistance values. Do not use coils, we cut out plates of nichrome, similar alloys. After manufacturing, the resistor is varnished, no high current is planned, the element should not be protected.
It is easier to wind inductors yourself. It is logical to use the 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, we type something like "online inductance calculator". We get a number of issuance responses. We choose the site you like, we start thinking about how to wind the inductance of the speaker 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 servomotors.ru website, taken from the reference book, which is given in the review, consider it to your health. The diameter of copper is 0.2 mm, the insulated core is 0.225 mm. We boldly feed the values \u200b\u200bof the calculator, calculating the required values.
It turned out a two-layer coil, the number of turns is 226. The length of the wire was 10.88 meters with a resistance of about 6 ohms. The main parameters are found, we begin to wind. A home-made speaker system is made in a hand-made case, there is a place to fit the filter. We connect a tweeter to one output, a subwoofer to the other. A few words about amplification. It may be that the amplifier stage will not pull four speakers. Each scheme is characterized by a certain load capacity, you cannot jump higher. The loudspeaker design is designed with a fixed headroom to match the load, often with an emitter follower. The cascade that makes the circuit work, full return on any speaker.
We believe they helped readers understand how to properly design a speaker system. Passive elements (capacitors, resistors, inductors) can be obtained and made by everyone. It remains to assemble the speaker cabinet with your own hands. And for this, we believe, it will not. It is important to understand that music is shaped by a range of frequencies cut off by improper device manufacturing. If you are going to make a speaker system, think about it, look for components. It is important to convey the splendor of the melody, there will be firm confidence: the work was not in vain. The acoustic system will last a long time, it will give 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 draw tons of information every day. Training resulted in hard painstaking work. I had to rummage through the dusty shelves of the libraries. Rejoice in the internet. Stradivari impregnated the wood of violins with a unique composition. Violinists of today continue to choose Italian specimens. Think about it, 30 years have passed, the cart is left behind.
The current generation knows the brands of adhesives, the names of materials. Necessary is sold by shops. The USSR deprived people of abundance, providing them with relative stability. Today, the advantage is described by the possibility of inventing unique ways to earn money. A self-taught professional cuts down cabbages everywhere.
