Dedicated to those who have free time
Opening 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 on 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 “minimize” 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 the shield and 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 assembling a similar structure for yourself, 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 to 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:
Although this type of acoustics is popular, it is far from 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 electric filter is added. Choosing the optimal volume of the housing, its geometry, and precise adjustment of the pipe length have 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 passed the thorny path and offer step by step instructions with a detailed description of what, how, and what needs to be made. 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 the crossover (crossover filter)
You decided to make multi-band acoustics. Do you need a measurement microphone? 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.
SPEAKERS
Everyone has one in their home monitor with TV and speakers. But here’s what’s strange: if a lot of time and money are spent when buying the first ones, then they buy acoustics most often on the “for change” principle. How many times have you seen expensive system systems in people’s homes with 10-core processors, sophisticated video cards for the price of a used Cossack, huge panels covering the entire wall. And next to it modestly stand computer speakers the size of a pack of cigarettes. At the same time, people don’t understand that the processor and video card will be outdated in a couple of years, and you’ll have to spend a lot of money again, the monitor will be replaced in 5 years, butsound speakers- it's forever. Even after 50 years, good speakers will not lose their sound! In the field of audio, the trend is not towards improving performance, but towards cheaper designs and more pop, and it is better now to invest very little money in good sound. And one of my friends, in response to my bewilderment, replied: “But in my system unit I have an audigy sound card for $30, everything should sound great.” Well what can I say!
Now you will learn only three basic rules that will allow you to have excellentsound speakers, and without extra costs.
First: Choosing sound speakers- take ONLY passive ones - there should be nothing in the speaker housing except the speakers themselves! Buy a separate amplifier, preferably a tube one.
Second: the main thing when choosing is not the manufacturer; the brand will cost more than half of the real costspeakers(ordinary Chinese companies do not sound much worse than Yamaha), and the dimensions of the acoustics also say volume, in liters. That is, the iron rule is followed - the more, the better. A volume of 30 liters and a weight of 10 kg and above are considered good.
Third: the diameter of the speakers installed insound speakers. Well, physically, a head with a diameter of 10 cm cannot produce good bass! The principle here is also: the more, the better. Aboutcalculation and production of a good case can be viewed on other resources
And lastly, no 6 channels, there will be no effect in our rooms anyway! Just a mess of sounds and noise. And multi-channel tracks are present only on expensive licensed discs. So, it is not often possible to realize the full surround sound of such a system.
Tweeters in inexpensivespeakersIt’s better to immediately replace it with new dollars for 20 pairs, the high ones will noticeably clear and increase the level.
Improved dynamic drivers
The most important part of the dynamic head of a loudspeaker is, as is known, the diffuser. It determines such parameters as the range of reproduced frequencies, unevenness of the frequency response, coefficients of nonlinear, intermodulation and so-called parametric distortions. These distortions are caused by the appearance in the emitted sound of components whose frequencies are an integer number of times less than the signal frequency (subharmonic oscillations). The timbre coloring of the reproduced signal also depends on its properties. At the same time, diffusers of mass loudspeaker heads, made of cellulose pulp together with the upper suspension and collar (the flat part glued to the diffuser holder), are considered the simplest and most inexpensive elements of the heads, requiring the least labor costs in production. This approach leads to the fact that diffusers are often unable to perform their functions at the level of the requirements currently imposed on acoustic equipment. Thus, the problem of improving this element of the heads is now very relevant.
Before offering radio amateurs a way to improve diffusers, let us briefly consider the features of their operation. On lower frequencies the diffuser behaves like an oscillating piston. The frequency response of a head with an optimally designed diffuser has a smooth shape in this area. At medium frequencies, the rate of change in the phase of the signal in the voice coil exceeds the speed of propagation of mechanical excitation in the diffuser material. The latter can no longer be considered as an oscillating piston, since not all of its sections oscillate in phase with the signal supplied to the coil. However, the damping of vibrations in the diffuser material at these frequencies is not yet high enough and, upon reaching the diffuser holder, they are reflected from it and propagate in the opposite direction. Due to the interaction of direct and reflected vibrations, areas with intense antiphase radiation are formed on the diffuser - standing waves (this excitation mode is called partial). As a result, significant irregularities (peaks and dips) appear in the frequency response of the head, the range of which in a poorly designed diffuser reaches tens of decibels.
At higher frequencies, the attenuation of mechanical vibrations in the diffuser material increases, and due to the weakening of the component reflected from the diffuser holder, standing waves do not form on the diffuser. The unevenness of the frequency response in this part of the range is determined both by the properties of the diffuser material and by the shape of its generatrix.
Nonlinear distortions of heads at lower frequencies (in the region of the main resonance frequency) are, as is known, a consequence of the nonlinearity of the diffuser suspension and unevenness magnetic field at the edges of the air gap in which the voice coil moves. At medium and high frequencies, the amplitude of the voice coil displacement is very small (tenths of a millimeter), and nonlinear distortions are caused by other reasons. One of them is Foucault currents that arise in the parts of the magnetic circuit (core and upper flange) during operation of the head, which, in turn, induce an EMF in the voice coil. To combat currents, Foucaults strive to reduce the electrical conductivity of the magnetic circuit parts adjacent to the voice coil.
The other two types of distortions, strictly speaking, cannot be called nonlinear, however, with the existing method of measuring them, when only the harmonic voltage is taken into account, they are considered nonlinear. The first of them is associated with the excitation of the so-called “structural overtone” in the diffuser material. It occurs due to insufficient damping of the material in response to mechanical excitation coming from the voice coil and gives the sound of the loudspeaker head a characteristic timbre coloring. The second type of distortion is caused by the formation on the surface of the diffuser of areas capable of emitting signals at their own frequencies in the presence of standing waves (their nature was discussed above).
The above analysis of the operating features of the diffuser shows that in order to improve the sound quality of loudspeaker heads, it is necessary to strive to reduce the intensity of vibrations reflected from the diffuser holder. For this purpose, diffusers of high-quality heads are usually made with a glued upper suspension made of a material with a high attenuation rate of mechanical vibrations. Such heads, however, are more expensive and low-tech to manufacture. At the same time, it is possible to improve the performance of the diffuser without using a glued suspension.
Improving loudspeaker heads Acoustics of the Moscow Electrotechnical Institute of Communications, under the leadership of Professor M.A. Sapozhkov, carried out work to improve the parameters of mass loudspeaker heads, as a result of which a way was found to increase the damping properties of their diffusers using vibration-absorbing mastics and coatings. In relation to heads, they must meet certain requirements: have good adhesion to the diffuser material, not change their properties (at least at room temperature) for a time comparable to the duration of operation of the head, and have a consistency at which the applied layer of mastic does not increase the resonance frequency heads due to reduced flexibility of the diffuser suspension.
The listed requirements are largely satisfied by the non-drying consistent mastic used in construction (TU400-1/413-78). It is a dough-like mass applied in a layer 4.5 mm thick and 200 mm wide on waxed paper and protected on the opposite side with a synthetic coating.
Before work, the mastic is diluted in gasoline to the consistency of sour cream. It is applied in the form of a ring strip with a width of 3...4 mm and a thickness of 0.5 (for heads up to 4 W with a light thin diffuser) to 1 mm (for more powerful emitters) on part of the upper corrugated suspension. For low-power heads with a suspension corrugated in the form of tangential strips, its peripheral half (adjacent to the collar) is covered with mastic. This can be done. for example, using a brush on the back of the diffuser through the windows of the diffuser holder.
When modifying powerful heads with a diffuser with a diameter of more than 200 mm, the mastic does not need to be dissolved. In this case, strips of the width indicated above are cut from the tape with scissors and glued (after removing the protective paper) into the first (from the voice coil) cavity of the corrugated suspension. After applying liquid mastic, the head must be kept in a ventilated area for an hour, remembering, of course. on compliance with fire safety rules.
The section of the upper suspension impregnated with mastic significantly changes its mechanical properties (losses due to viscous friction increase sharply), due to which the absorption of mechanical vibrations is enhanced and the damping properties of the diffuser are improved. Mechanical vibrations are absorbed twice; both in the forward direction (when propagating towards the diffuser holder), and in the reverse direction (from the diffuser holder). As a result, the possibility of formation of areas with intense antiphase radiation on the diffuser is eliminated. The consequence of improving the operating mode of the diffuser is not only a decrease in the unevenness of the frequency response of the loudspeaker head, but also a decrease in distortion caused by partial excitation.
The effectiveness of the proposed method for improving dynamic heads can be judged by the frequency response (Fig. 1-6), recorded in an anechoic sound-measuring chamber (the frequency response of the original heads is shown with a dashed line, modified ones are shown with a solid line; the acoustic design in all cases is a closed box filled with sound-absorbing material).
Analysis of the given characteristics shows that as a result of the modification, the frequency response of all heads has significantly improved: their unevenness has decreased, especially at mid-frequencies of the operating range, peaks and dips have disappeared or decreased. The 15GD-10 head stands somewhat apart: after modification, along with a decrease in the unevenness of the frequency response at medium frequencies, there is an increase in it at frequencies of 3...5 kHz. This is explained by the fact that the 15GD-10 head is equipped with a high-frequency emitter glued into the main diffuser, the oscillations of which in the specified frequency band interact with the oscillations of the main diffuser (optimized for an undamped diffuser, this emitter turned out to be not entirely suitable for the modified one).
In addition to measuring the frequency response, harmonic coefficients in the range of 250...10000 Hz were measured for the modified heads (ZGD-42, 4GD-53 and 1GD-50). At almost all frequencies, nonlinear distortions were significantly reduced.
An important advantage of the proposed method for improving the parameters of heads is maintaining their sensitivity, while the use of a glued suspension, reducing the radial rigidity of the moving system of the head, forces developers to increase the width of the working gap, as a result of which this characteristic worsens.
It should be emphasized that the above-mentioned improvement in frequency response and reduction in distortion was achieved by modifying ready-made heads with diffusers already optimized during development. If you cover the diffusers (or rather, their suspension) with mastic during the manufacturing process and only then optimize their parameters, then we can assume that the results will be even better. In combination with additional acoustic damping of mid-frequency drivers [L], the proposed method of modifying diffusers can significantly improve the sound quality of loudspeakers based on inexpensive mass-produced drivers.
LITERATURE: Popov P., Shorov V. Improving the sound quality of loudspeakers. - Radio, 1983, No. 6, p. 50-52.
V. SHOROV
RADIO No. 4, 1986″
What is Guerlain
Guerlain is a SEALING TAPE. It is used for sealing interpanel seams in panel buildings and similar places where sealing is needed. It is produced in the form of a “sausage” with a diameter of about 5-6 cm or in the form of rectangular pieces about 30 cm long and assembled in the manner of a machine gun belt. Packed in polyethylene, because... The mastic is terribly sticky and the only thing in the world that it doesn't stick to is water. Colloquially called "Velcro". Guerlain deposits are found on construction sites, for example, where panel residential buildings are being built. Guerlain supplies usually run out pretty quickly. In addition, it can simply be closed in a container or warehouse, so you should take a good look and approach the worker who is involved in this work (sealing), because The guard doesn't always have the keys.
You should take guerlain in “sausage” - it is pure, because... Guerlain in “machine gun belt” is produced with a mineral filler, which is not at all needed to impregnate the speakers. You can distinguish it by color - pure guerlain has a slightly (!) grayish yellow-white color with a slight creamy (or coffee?) tint and is terribly sticky. When heated, the sticky properties increase and guerlain becomes more plastic, and when heated strongly, it becomes fluid, but flows as if reluctantly. Guerlain with filler is noticeably darker and even has a brown color, it is not so sticky and the “grainy” structure is clearly visible. There is also white guerlain with white filler - again, it is given out by its “gritty” structure and slightly reduced stickiness. Pure guerlain is absolutely homogeneous and looks like some kind of candy mass or marshmallow.
Mastic dissolves in gasoline relatively slowly, so it should be thrown into gasoline in small pieces, the jar with this should be placed in a warm place and stirred regularly. Gasoline can be used for aviation or for lighters, but without any additives like tetraethyl lead, so that you don’t have to breathe in them in the future.
By the way, the device with which guerlain is stuffed into the cracks looks like some kind of machine gun, or, more precisely, a flamethrower with a wide barrel; in the top in the middle there is a hole into which the tape (or “sausage”) is tucked and works on the principle of an electric meat grinder. The remains of the tape are in the hands of the worker. Using knives, the entire polyethylene shell along with the contents is chopped into small pieces, mixed, the mass is heated under mechanical action and comes out through the barrel as ready for use as possible. A worker with this device, especially after a long drinking binge and without a hangover, really looks like a machine gunner from DOOM1&2 and it is dangerous to approach such a worker without a bottle. 😉
Finding it now is almost impossible. Builders sometimes didn’t hear the word “guerlain”; they were interested in it themselves. But it is possible that some of them still encountered this SEALING TAPE in their work in those distant times, but sometimes did not know what kind of material it was and what it was called... Ideal for impregnating paper corrugations of speakers. I myself am the owner of a small quantity of guerlain. I impregnated a number of pairs of speakers and was pleased with the results. Some have been working for more than 5 years. The material has not lost its properties. In general, I recommend it. The impregnation technique has been repeatedly described in Radio magazines from the 1980s. Only the corrugation of the speaker is impregnated with Guerlain, and only if it is made of paper or, in extreme cases, made of fabric, and in no case the diffuser itself, unlike Vorobyov’s chitin impregnation, with which the diffuser itself is impregnated to increase its mechanical strength. Without going into details, impregnating corrugations with guerlain makes the corrugation more elastic without reducing its strength. This will allow us to reduce the resonant frequency of the speaker and make a good decoupling between the diffuser and the basket, which will prevent the propagation of waves from the diffuser to the speaker basket...
***
N.B.
Most likely, the beige mass that came in 100x60x30mm briquettes has nothing to do with guerlain. This is the so-called cannon lard, used at that time in the automotive industry and car enthusiasts for anti-corrosion treatment of hidden cavities of the car body, on a par with MOVILE, which was popular at that time. By the way, it is ideal for applying to the surface of wheel arches before installing plastic fender liners. Less prone to leaching compared to liquid anti-corrosion materials. I myself used it to treat the body of my first car, proudly called Zhiguli.
It dissolves well in gasoline, kerosene, white spirit and other solvents. When frozen, the mass is solid, beige in color, and was previously produced in briquettes. Even now you can buy it at car markets.
The effect of treating corrugations with this mass, I think, will be similar to the effect of treating with castor oil or glycerin. But the latter should not be used categorically because the latter completely kill the corrugation and the paper begins to burst. Guerlain is a more homogeneous and elastic mass, not prone to drying out and losing its qualities. Cannon lard is still prone to drying out and hardening. So, I think it’s hardly worth using it for impregnating corrugations. If you still want to try, I think you should first try on another speaker, not your favorite one, of course.
***
Go to a hardware store and ask for weather stripping tape. There are tons of options. This is GUERLEN. I use SOUNDBAND tape both for damping the speaker baskets and for impregnating the corrugations. Dissolve in gasoline and white spirit, cutting into small pieces. Throw into the bottle along with the metal backing. The guerlain will dissolve and small pieces of the metal backing will settle to the bottom.
***
Everything is correct, just a few nuances need to be mentioned:
- dissolve only in Galosh gasoline, because White spirit dissolves paper fibers,
- it’s better to put it in a jar (transparent) in a water bath, then leave it for a day, use only the top transparent honey-like liquid,
- cover only the suspension - the corrugation, the diffuser in no case, (on the edge you can)
- you can buy polyisobutylene (high molecular weight) instead
***
You need to apply it while understanding what you want from the speaker. Maybe you don’t need to smear at all, but just soften the suspension, the washer, in order to lower the resonance and increase the movement of the diffuser (microdynamics). It depends on what kind of speaker you have and what you want to make of it. This is how Frez slides down. after impregnation. And the quality factor decreases at the resonance frequency. Which has a positive effect on the overall frequency response and nonlinear distortions.
Interesting notes on impregnating speakers with guerlain from the diyaudio.pp.ua forum
This is the kind of guerlain (sealed airtight) you can find today
Dmitry Kabanov: We've discussed various aspects of indoor audio before, and we did so in the winter when we discussed waterproof speakers that are resistant to snowfall. Now it’s almost autumn, it’s raining, and it’s worth returning to this topic.
Timofey Shikolenkov: Good topic. But first, let's talk about a related topic that is with us every day - let's talk about equipment, sound in public places. When you come to a bar, sometimes you see a tape recorder on the counter, almost a cassette center, playing the radio. There are cases: you come to a recently opened establishment, which has undergone a beautiful renovation, and at the same time you have bought some strange equipment and placed it on the counter. This oddity has always surprised me.
The second thing that surprises, however, is less common: in some rooms where ceiling speakers are usually used - in large spaces they practically do not take up space and produce uniform sound - instead of special built-in speaker systems, car speakers are installed.
Dmitriy: We realized that there was no need to put a tape recorder on the shelf, so we bought some kind of 5.1, 2.1 center and decided to distribute it all in the corners on the ceiling.
Timofey: I have even seen situations where [in public spaces] they installed a car radio with a transformer and connected wires to car speakers located on the ceiling. People don't realize that car speaker systems are designed to fit within the volume of a car's body.
It is important to understand that for each speaker system a very important factor is the acoustic design, that is, in which box or case it is located.
Dmitriy: I imagine a cafe the size of an average sedan. It would be great to sit.
Timofey: Unlikely. People are trying to reinvent the wheel. They are probably guided by the fact that professional equipment, and the word “professional” always scares everyone, is expensive. Professional speaker systems, which are designed for voice acting and background music, are cheap.
There are such options for acoustic systems: a small speaker, ceiling or wall-mounted, costs about a thousand rubles. It needs an amplifier. In such cases, hybrid devices and mixer-amplifiers are usually used. This is one box that can be placed on a rack or other convenient place.
Professional equipment is designed to work 24/7 – around the clock for a long time. Household audio equipment is not designed for such use, cannot and should not work this way. It has a certain, finite service life and operating conditions.
In this case, an amplifier is needed in any case. Maybe people find automotive equipment the most familiar, and [that's why] they install it.
The situation is similar when an office buys a [home] printer intended for small volumes of printing and prints on it from morning to evening. During the warranty period, the printer breaks down, and the workers do not understand what happened. It’s good that during the warranty period, and not a day later. The device is not intended for use in this mode.
Returning to the topic of audio: the economic aspect is unclear, it is not justified. Is the same car stereo costs money, it still needs to be adapted to work outside the car.
Dmitriy: It will be more expensive, and it must be fixed, but this is not provided for by the design.
Timofey: The money will be the same. Issues of reliability, stability, and volume are also important. I've been wanting to talk about volume for a long time. Everyone likes to measure volume in Watts, even though it is a unit of power. And people think that the larger the number written on the speaker or amplifier, the louder it is.
Of course, these quantities are combined to some extent, but loudness is not measured in Watts. Loudness is measured in Decibels - this is sound pressure. This is the primary quantity in which loudness is measured.
In professional equipment, sound pressure is always indicated in the description of the characteristics of speaker systems. It is very important. To understand what numbers may be indicated there: ten decibels is a quiet whisper, the rustling of leaves, fifty decibels is the sound pressure that we create during a calm conversation.
The sound pressure is different in headphones or speakers. Seventy to seventy-five decibels is a scream, ninety decibels is a subway car passing by us. One hundred and twenty decibels is the pain threshold; a person cannot bear more.
If we want to sound a room in which people sit and work, it should be quiet music. If this is a warning system... in English there is a phrase “public address”, in Russian you can try to translate this as “broadcast”, “radio broadcast”, “warning system”. There is simply no such phrase in the Russian language.
Dmitriy: This is similar to the system that used to be in [Western] universities, when some kind of announcement is turned on or a local local radio station is broadcast. Something like that.
Timofey: This is the same as apartment radio points, that is, sockets into which a loudspeaker is plugged in. Returning to power: there should not be more than 85 decibels in the room where people who need to be notified are sitting, and the music should be even quieter. In professional acoustics, sound pressure is usually indicated at a distance of 1 meter at a power of 1 Watt.
Let's move on to power. If we take small ceiling or wall speakers, in which the maximum sound pressure is 92 decibels, that is, more than we need, then it turns out that at 1 Watt we will already get what we need.
Dmitriy: It turns out that you don’t need to buy 100-watt amplifiers and spend a lot of money on it.
Timofey: The second question arises: why is it recommended to use such equipment? It's very easy to calculate power. If the power on the amplifier is, for example, 100 W, this means that we can connect one hundred speakers with a power of 1 W to it. Marketing “tricks” are rarely used in professional equipment. “They added an extra zero, and everyone immediately ran to buy it, it’s so loud, so powerful,” there’s no such thing there.
If on Public address systems it is written that the speaker power is 2 or 3 W, 5 or 20 W, then it is so. The speaker is designed for the power that will be supplied from the amplifier. The volume depends on the room and distance - we have already said this.
Another advantage of such systems: these systems allow the use of fairly long cables; sound can be transmitted over long distances - several hundred meters. It turns out something in between: on the one hand, professional use, on the other hand, not quite household ones.
Dmitriy: Considering that the cable is laid along the walls, and the room can be large, sound recording of fifty square meters will require tens of meters of cable.
Timofey: Of course, and it's very convenient. Why? Traditional Hi-Fi systems require each speaker to have its own separate cable, this is a given. In the case of Public address systems, this is not required. You can connect a large number of speakers in parallel, as many as you need.
Interestingly, such speakers have a power switch, that is, conditionally, a volume control for each speaker. In a bar, restaurant, where the cash register is located, you need the sound to be quieter, but the speakers can be the same.
Dmitriy: You can physically limit [the power supplied to] these speakers...
Timofey: Yes, exactly these speakers without any adjustments in the amplifier. And on the amplifier there is a general volume control and, accordingly, in some zones we can make it quieter, in others louder. In this case, the power will change, which will need to be calculated based on the capabilities of the amplifier.
It would be nice to make a small power reserve so that the amplifier does not operate at its maximum. If we buy a 35-watt, 50-watt amplifier, then these are real and sufficient numbers, we have already discussed this.
Dmitriy: Let's talk about prices.
Dmitriy: We can physically limit the power on certain speakers, and if we have some old systems from what we were already using, for example, an old stereo system, can we partially use these speakers, in addition to what we buy?
Timofey: In no case. Because the main difference between these systems is that they increase the amplitude by about five times when transmitting. That is, the amplifier contains a step-up transformer, and no Hi-Fi or non-Hi-Fi, that is, ordinary household speaker systems, are designed for this.
The speakers have a step-down transformer, and the speaker does not work in extreme mode. If you connect ordinary speakers that are not designed for this, they will work at the limit for some time and quickly fail. There is no need to use such options. One column for such a professional system can cost about a thousand rubles. A good one costs two thousand rubles, a very good one costs three to four thousand.
They can be of different power, but if it is background audio, then, as a rule, these are ceiling or wall systems. It all depends on how to place them in the room. An outdoor system option is possible, and all this is connected to one amplifier.
Dmitriy: If we take a small cafe, is it 50-70 thousand rubles for all the equipment?
Timofey: No. Twenty, maximum thirty thousand rubles, and only if we want to build something of high quality. If you just do background sound, then you can limit yourself to twenty thousand, including waterproof speaker systems on the veranda. It’s strange that people are trying to solve the problem in complicated ways, despite the fact that there is a solution that is very inexpensive and, most importantly, easy to install.
An inexpensive cable is taken, laid along the wall, a break is made in the right place, a speaker is connected, which is placed in this place. You can add speakers anywhere if you have cable supply. No need to run a hundred cables to a hundred speakers. All this is very simple, convenient and durable.
Dmitriy: Does it make sense to think about wireless solutions?
Timofey: No. Wireless solutions exist, but they are household ones. This means that they are not designed to last long.
Dmitriy: We dealt with the case of a small cafe. If we have a medium-sized cafe and are closer to a large one, then we can observe a division into two or three segments, where, among other things, some kind of mini-stage can be used for micro-performances.
Timofey: Yes, this often happens, since all these systems and mixer-amplifiers are usually multi-channel. There are, of course, single-channel ones and there are quite a lot of them, designed for several zones.
In this case, you can adjust the volume and connect a microphone. Naturally, they all come with microphone inputs: with one, two, three, four, various sources. You can send different sources to different zones. All this, again, is done once and then controlled in one place by one simple device.
Dmitriy: If necessary, you can bring the sound that comes from the microphone from the person performing to the farthest corner and zone, or, on the contrary, remove this sound and send music there that does not interfere with people enjoying what they are doing.
Timofey: The main thing is that these planned zones are connected to the amplifier at the very beginning different exits, that is, the outputs of different zones. If we initially created only one zone, then we should not hope that the speakers themselves will understand what sound to reproduce.
When we talk about performance, about live sound, such systems are not suitable. As a rule, if we are talking about restaurants and bars, then other equipment is used for stage equipment - mixers, large professional stage acoustic systems. In establishments that simultaneously have sound during the day and a stage in the evening, perhaps a disco, or live performance, two systems are used.
Firstly, this is a Public address, that is, there is sound during the day, and in the evening there is powerful professional acoustics, to which you can connect musical instruments. This is such a hybrid.
Dmitriy: Compared to a small cafe, how much more expensive will this solution be?
Timofey: Depends on how many more acoustic systems there are, how different sources are needed, for example, simple amplifiers can be divided into zones. Take the microphone: there is background music that plays everywhere, and there is an automatic function to mute the music when some kind of alert starts, as soon as you start speaking into the microphone. Typically, that's all.
If you need to do something more, you can install two mixer-amplifiers and make two separate systems. There are multi-zone, more serious mixer-amplifiers or separate amplifiers and mixers. The scope for creativity is unlimited. It all depends on the task. The main message I wanted to give to our listeners is that it is very simple.
A friend of mine, opening a cafe, turned to me for help in the field of sound. We did everything in the evening. More time was spent drilling holes in the walls to mount the wall speakers. The cable was laid very quickly, and the speakers were connected where needed.
Dmitriy: The main conclusion: “professional” does not mean that it is expensive, it means that it is necessary for the job, and not so difficult - it’s not like assembling a rocket.
Timofey: As for professional - in this area, “professional” means “inexpensive”. And you need to understand that the equipment is very different, and if a speaker is similar to a speaker, this does not mean that it will be suitable for every task. The tasks are different, and there are many of them.
And if we know which equipment is suitable for which tasks, then we can easily solve them without spending a lot of money, investing in the future, because it will work for a long time without requiring maintenance. This is reliability, quality, and reasonable spending of money, which is what everyone is looking for.
Dmitriy: Are there any other questions that are often asked by those who want to get into this?
Timofey: We can talk about street things.
Dmitriy: What to do in autumn and winter?
Timofey: It happens that people buy waterproof speakers, but they are very different. There is a standard that describes how much moisture can get on speaker systems.
There was a case when a client came with a desire to install speakers in the pool in the water. We couldn’t find out from him why this was happening, because nothing would be heard. Unfortunately, they couldn't help him.
In general, there are different classes and you need to understand that if it hangs on the street under a roof, and it is a humid environment, water will not flow directly, this is one system, if it is a completely open space - another system, if a sauna with one hundred percent humidity - third system.
Dmitriy: There is a moisture protection class that you need to pay attention to.
Timofey: You need to look in the description for what application this acoustics is used.
Dmitriy: If you remember the systems that look like floor stones and so on. How much should it be used outdoors?
Timofey: There are such very interesting and beautiful landscape solutions. You need to carefully read what they are for, external or internal. If the speaker looks like a beautiful pebble, this does not mean that it can be placed on the path. You need to look at what class of protection against moisture it is.
If it is assumed that the column will be placed in a lowland, then the equipment must be of the appropriate class, or it is necessary to reorient itself and place the column in another place. Nothing will change fundamentally, plus or minus half a meter is not very important, and the system will be more durable.
Dmitriy: Are there any issues with impact resistance? Accidental contact with furniture? Can people hurt something?
Timofey: No, as a rule, everything is built into the ceiling or hung on the walls or in the corners. Impact resistance is difficult to apply here. Speaker systems are made of plastic with various elements; of course, you cannot hit them with your fists.
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