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Modernization of S-90 speakers by replacing standard cabinets with labyrinthine design of bass speakers

Upgrade of the S-90 labyrinth design by stuffing the corners with cotton wool and sticking them on the inner surface of the wool blanket
At first, only the frontal knees of the labyrinth were covered with wool, then the side surfaces too
Ready labyrinth S-90 with inner surfaces covered with wool

Remaking the most famous speakers of the USSR Radiotekhnika S-90

Alexander Rogozhin came up with the know-how of how to convert the Radiotekhnika S-90 speakers, most well known to most Russian-speaking people, into labyrinthine housings. The article is devoted to the most widespread and for more than 20 years considered the standard of acoustics Soviet period, which in its first generation was called 35AC-1. And Rogozhin proposes to make speakers from 35AC-1 (Radio Engineering S-90) with the name “Cheap, loud and super-bass”!

Ode to speakers Radiotekhnika S-90 (35AC-1)

There is no person who speaks Russian, Ukrainian, Belarusian, who at least once in his life has not heard the famous Soviet Radiotekhnika S-90 speakers, or has not had one of their modifications produced in the mezzanine, in the closet, at home or on the hacienda more than 30 years. You can think whatever you want about their sound, appearance, rubber speakers, but in fact these are the MOST common “People’s” speakers in the vast former USSR. Even now, tens of thousands of them work in the systems of music lovers, who feel sorry to throw them away because Compared to the branded “remake” they play very, very well.

If a person is faced with a choice on which speakers to listen to music on: with bass, loudly, and for ridiculous money, then despite all the disadvantages of the Radio Engineering S-90, they have practically no competitors, and even less so before. In the late USSR, in addition to the S-90 speakers, of course, “clones” appeared, taken from the best foreign samples, for example, Electronics 100AC063 or 75AC-063. But they were very expensive and not widespread; they could not compete in popularity with the S-90 acoustics. It was basically impossible to get three full-fledged bands with the same power as the S-90, a 10-inch woofer and almost nothing from any other speakers. This is even more relevant now.

Tens of thousands of these speakers still work in the rooms of young and not so young people who do not have the opportunity to carry out complex projects on expensive imported dynamic heads. For obvious reasons, many of our compatriots are in no hurry to abandon the Radiotekhnika S-90 acoustics. They are not eager to run to the store and buy beautiful branded speakers, which for the most part differ from the S-90 only in appearance, which often cannot be said about their sound.

And yet we all love to listen to music, it happens to everyone good mood, when you want to turn it on “to the fullest.” Everyone loves high-quality bass, without which almost any music loses its foundation and most of its emotions. Many styles of music without bass are generally impossible to listen to, because... without it, the lion's share of the important music information. The soul asks UUUH! And low frequencies are actually a very delicate thing; in order to sound adequately and make an impression, they require large speakers, cabinets and power. But even with all this (in large speakers like the S-90), the bass often turns out buzzing, drawn out and indistinct, and does not give us the “buzz” that it is supposed to give. We quickly get tired of such bass and start turning the tone control knobs or switching the equalizer modes on the receiver. And instead of getting pleasure, you get annoyed and think about the imperfections of this mortal world... Almost all music lovers and owners of this acoustics, in particular, have found themselves in this situation more than once.

Low Frequency Problems S-90

The reason that over the past 30 years, owners of the Radiotekhnika S-90 acoustics and its numerous modifications are not satisfied with its sound and are somehow trying to cope with this problem lies in several reasons. The main problem with the S-90 speakers, confirmed by repeated research by specialists, is an error made when designing the low-frequency design of the 30GD-2 speaker. Having entered the series, the error led to the fact that the potential for high-quality reproduction of low frequencies, originally inherent in the Radiotekhnika S-90 model and its modifications, is not realized even by 20-30% of the possible ones.

A huge number of S-90 owners, almost from the moment they appeared on sale in the 80s until today, have been trying to improve the low frequencies of these speakers by conjuring with filters, altering the bass reflex pipes, strengthening the original housings and filling them with anything.

Dear music lovers! I urge you to stop doing nonsense, because... this is absolutely useless... The S-90 speakers from the factory have a housing with a volume of only 45 liters - NOT corresponding to the optimal operating mode of the 30GD-2, 75GDN1-4 speaker installed in it. You can even trim it with the roots of rare species and cover it with porous rubber on all sides - it will still NOT work correctly.

That is, the question of radically improving the performance of these speakers at low frequencies, no matter how regrettable it may be, is that the question of replacing the housing arises in full force.

The task is somewhat complicated by the fact that over 30 years a huge number of modifications of 35AC-1 speakers with 30GD2/75GDN1-4 (8) low-frequency speakers have been released, which have a wide range of parameters. In the new enclosures, this problem has been largely resolved and allows speakers from the earliest releases to the latest to feel correct. The setup of new enclosures is “stretched” and allows you NOT to specifically select low-frequency speakers.

Mid Frequency ProblemsS-90

Almost all owners of s-90 speakers note unpleasant overtones and greater unevenness of output at mid frequencies, which become especially noticeable at medium and high volumes. All grandiose projects to remake filters by installing expensive imported capacitors, replacing wires, resistors, etc. as well as options for gluing halves of a tennis ball onto the diffuser of mid-frequency heads, etc. fail.

The main reason for the unsatisfactory sound at mid frequencies is not the 15GD-11 speaker at all, but its acoustic design. This “glass” covering the midrange head from behind has a tiny volume and is the second mistake made by the engineers who designed the S-90 speakers. The “glass” of the mid-frequency head 15GD-11 (20GDS...) has everything wrong, from the volume and configuration to the internal design. When replacing the housing of the s90 speakers with the correct one from the point of view of the design of the woofer, the mid-frequency speaker should also be designed accordingly.

Of course, replacing the “minuscule” standard glass with an acoustic design that is optimal in volume and shape will not make the 15GD11 head a different speaker, but will give it the opportunity to do what it can do initially.

What you can get

As a result, the updated S-90 speakers will sound radically different not only at low, but also at medium frequencies. Presented on the Internet large number attempts to remake the S-90 speakers in order to “deceive everyone” and turn them into studio monitors. Attempts concern everything except replacing the main “weak point” - the body, and most often turn out to be failures. While keeping the S-90 speaker cabinets unchanged, to radically change the sound, you need to change the speakers to modern ones or design three-way speakers from scratch, which most music lovers do not dare to do.

I suggest leaving the original set of S-90 speakers untouched. Their value lies in the minimum budget and, no matter how clever you look, their performance has been proven over decades of operation in the harshest conditions.

One thing that can be fundamentally improved about these speakers is to “get the most out of their speakers.” To do this, you need to make an acoustically correct housing for the original set of speakers and filters. As a result, you can reach a fundamentally new level of sound quality from these speakers without spoiling anything.

As a bonus, you don’t have to throw away the old cases and, if necessary, the “stock” S-90s can be put back together and sold to some lover of authentic speakers made in the USSR.

Problems with native boxesS-90

• The wrong amount of low-frequency design does not provide the required level of pressure on the low frequencies;
• Non-optimal bass reflex tuning frequency leads to uneven bass response and poor bass quality;
• The “bass reflex” type of low-frequency design in combination with a “tight” speaker on a rubber surround leads to an extended and monotonous “hum” at low frequencies, instead of a clear striking bass;
• Phase-inverted acoustic design leads to significant unevenness of sound pressure at low frequencies in the room, and places demands on obtaining high power from the amplifier;
• The weak walls of the S-90 speaker boxes lead to a loss of efficiency at low frequencies and produce noticeable overtones when operating at high volumes;
• Poor sealing of the boxes prevents even the low-frequency design that the S-90 speakers have in the stock version from working;
• The extremely small volume of the cap of the mid-frequency head 15GD11 (20GDS-) leads to “squeezing” of the mid-frequency dynamics;
• Non-optimal damping of a small-volume midrange box leads to noticeable overtones and “nasality” in the midrange;
• The shape and dimensions of the S-90 speaker cabinets in the stock version require their installation on furniture, which leads to a “wobbly position” of the speakers, resonance of the furniture at high volumes and, ultimately, to deterioration in the sound of low frequencies;
• The “low-profile” shape of the speaker housing requires installation on specialized stands for acoustics, which ultimately increases the cost of the system. Installing the 35AC-1 speakers on the floor leads to a lack of high frequencies and an incorrect scene.

Advantages of new buildings

• The design of the low-frequency head is a quarter-wave labyrinth with its radical advantages at low frequencies over a bass reflex ( detailed description Here);
• The optimally calculated frequency and quality factor of the quarter-wave resonator tuning provide a wide band and optimal level of low frequencies;
• The highest rigidity of the box gives the highest possible efficiency, clean, elastic and biting sound at low frequencies;
• The high-volume, hard-box midrange driver produces a lively, open midrange and clear vocals;
• The placement of the midrange and high-frequency speakers on the front panel, maintaining the distances to the cabinet walls according to the “golden ratio” principle, reduces diffraction phenomena on vocals and high frequencies and makes the sound much more comfortable;
• With the new enclosures, the acoustics turn into a classic floor-standing design with midrange and high-frequency speakers optimally positioned in height;
• The speakers have narrower and taller front panels than standard S-90s and do not require any stands. The appearance of the speakers is improved many times over.

Music lovers constantly start debates about which speaker system to choose for comfortable listening to music at home. And this is no accident: the entire contingent was divided into two camps. The first believe that it is worth shelling out a tidy sum to buy a cool Hi-Fi (or better yet, Hi-End) system in order to be happy and forget about headaches about this topic for the rest of your life. But there are also those who are not ready to give up their entire life’s savings for expensive acoustics (instead of the required car or apartment), and therefore consider the best option to purchase simpler equipment or improve the good old classics to good sound.

In this article we will talk about one of the most popular audio systems produced during the USSR, which could not leave any of its owners indifferent. Speakers S90, technical specifications which are capable of exciting consciousness to this day, became one of the highest achievements of the Soviet company Radiotekhnika.

Speaker models

The very first thing worth mentioning is the real and full name of the speaker model - 35AC-012. An important factor is that this acoustics was produced in several variations. The most popular of them are S90 and S90B. There were also S90i, S90D and S90f models, but they were not widely used and are now almost unheard of.

The model with the postfix “B” differed from the usual “nineties” in a wider range of reproduced frequencies. Another significant difference was the introduction of an electrical overload indicator for the speakers. The recommended power of a high-quality amplifier for these speakers is in the range from 20 to 90 watts. It is also worth noting that Radiotekhnika S90, S90B (and other modifications) were the first models of speaker systems that met international requirements for Hi-Fi equipment.

Design

The case in which the S90 speakers are enclosed is, in fact, a one-piece rectangular box made of valuable species tree. The thickness of the speaker walls reaches 16 mm, the front panel is made of plywood 22 mm thick. The internal joints of the cabinet walls are connected by special elements that increase the rigidity and strength of the structure, but do not interfere with high-quality sound.

If you look at the device from the front, the speakers are arranged in the following order (from top to bottom): tweeter, midrange speaker and woofer. Also on the front panel of the S90 speaker you can see the frequency response (amplitude-frequency response) graph and the bass reflex hole. While the frequency response is located at the top or bottom (depending on the acoustic model), the bass reflex is always located at the bottom. This was done for reasons of proper design for better sound and giving the speakers good bass.

Speakers S90: characteristics

If we take the regular S90 as an example, they have dynamic direct radiation heads installed. More precisely, a high-frequency head 10GD-35, a mid-frequency head 15GD-11A and a low-frequency head 30GD-2 (in later models - 75GDN-1-4).

Equipped with two step playback level controls to adjust the midrange and treble in the ranges from 500 to 5000 Hz and from 5 to 20 kHz. Each regulator moves in three fixed positions. In position “0” there is no obstacle for the signal from the crossover filter, and it is fed directly to the corresponding head. When using the “-3 dB” and “-6 dB” positions, the signal is attenuated by 1.4 and 2 times, respectively, relative to the “0” position. By switching the selected control, you can change the timbre of the sound.

The rated power of the S90 speakers is 90 Watts, while the nominal power is 35 Watts. The nominal electrical resistance of this speaker system is 4 ohms, and the range of frequencies available for playback ranges from 31.5 Hz to 20 kHz. The nominal sound pressure of the S90 is 1.2 Pa. I would like to note the rather impressive dimensions of one column - 71.0 x 36.0 x 28.5 cm, and the total weight of the entire system reaches 30 kg.

Speaker circuit and connection to the sound source

In order to understand whether it is worthwhile to modify any speaker system, you need to study all the data and aspects of the equipment. Below is electrical diagram speakers S90. Anyone, even a novice radio amateur, can understand it; you just need to have at least basic knowledge.

Another important point is the correct connection of the speaker system. After all, if something goes wrong, even during connection you can, without meaning to, damage the equipment. You don't need to be a professional to figure out how to connect S90 speakers. The main thing is to have at least 20 watts with the amplifier (in this case, most likely, the sound will not be loud enough for large rooms), but not more than 90 watts. In case of exceeding permissible value amplifier power, the user risks being left without acoustics due to its breakdown. To connect, you will need regular speaker wires, which must be connected to the terminals on each speaker and amplifier. The main condition for connection is compliance with polarity.

Revision 35AS-012

As it becomes clear from the description above, it itself has good technical characteristics and is capable of “rocking up” even small public spaces. But for home use, the most sophisticated music lover will prefer to modify the S90 speakers with his own hands. And all because the acoustic systems of the Radiotekhnika company, assembled more than twenty (or even thirty) years ago, did not already have high build quality and the materials used in those years.

Parsing

In the event that the acoustics were purchased in used condition and are currently well-worn by life, it is worth paying attention to the appearance. To do this, you need to disassemble the S90 speakers, first placing them on their “back”.

When removing the speakers, you need to take into account that the tweeter and midrange heads are attached to the housing using the same screws as the linings. The woofer is attached separately, and you need to be as careful as possible not to damage it when unscrewing it.

The HF/MF controls are much easier to dismantle than they seem. All you need to do is carefully remove the decorative plugs that are located in the center of each regulator. After this, using a screwdriver, you need to unscrew the screw that is revealed to the eye and remove the regulator handle itself. Plastic cladding you need to carefully lift it on both sides using flat objects and take it out, and unscrew the four screws remaining under it. Then you can push the S90 inside the speaker, not forgetting to unsolder it from the filter.

The cotton wool bags located inside the case must be removed. Again, if the previous owner of the speakers did not forget to return them to their place in case of disassembly.

You should first unsolder the panel with filters from the output on the rear side of the speaker, and then you need to dismantle it by unscrewing the screws. Now you can remove the panel with the terminals attached to it.

Appearance and body

If the grilles and decorative covers of the speakers are “tired,” then it is worth straightening them and painting them, having previously sanded and degreased them. This will give the speakers a fresh look. The body of the S90 speaker becomes loose over time and can be strengthened if desired. This will result in a better sounding woofer.

This can be done in various ways, including installing spacers and additional corners inside. It is also necessary to pay attention to sealing all joints and seams using conventional plumbing sealant. In addition, you can glue the inner walls of the case with foam rubber (except for the front), which will increase the volume of the latter.

Terminals and filter

Knowledgeable radio amateurs advise replacing the standard speaker terminals with universal type terminals with gold-plated connectors. The installation location must be lubricated with sealant and the panel with terminals must be put in place.

Considerable attention should be paid to the sound filter. If it was attached to the body with metal screws, then the filter settings will be lost. There are cases where the filter was assembled on a metal plate. This can be corrected by transferring all nodes to a plywood panel. The circuit of the filter itself may have been changed at the manufacturer due to different parameters of the speakers, so you should make sure that everything is assembled in accordance with GOST. If there are jumpers in the filter, then they must be removed and replaced, for example, with an oxygen-free copper cable with a cross-sectional area of ​​4 mm 2. It is worth removing the attenuator from the circuit, as it simply distorts the sound, and replacing the wires used to connect the speakers to the filter.

For low-frequency speakers, a wire with a cross-section of 4 mm 2 is suitable, for mid-range speakers - with an area of ​​2.5 mm 2, for high-frequency speakers - with an area of ​​2 mm 2. After these simple steps, the filter must be returned to its place and covered with foam rubber.

Speakers and other "trifles"

New seals should be cut for the speakers. This can be done using cheap or simply outdated computer mouse pads. This is the simplest option. After this, it is worth returning them to their seats and installing decorative overlays and nets.

Before installing the regulators in place, you will have to remove all resistance from them. When installing them in place, it is imperative to use sealant, as when installing a bass reflex.

Through such simple manipulations, the S90 speakers acquire new life. The sound quality becomes an order of magnitude higher, despite the low costs. As a result, we can say that if you don’t have the money for expensive 2.0 format acoustics, you can use a similar option and become the happy owner of the time-tested Radiotekhnika S90 speaker. If it happens that only half of the speakers are available, do not be upset. After all, it is remarkable that the S90 speaker, a photo of which can be found on almost any site for acoustics lovers from the times of the USSR, can work alone and give good results.

Rated power... 35 W

Nominal electrical resistance... 4 Ohm

Frequency range... 31.5-20000 Hz

Nominal sound pressure... 1.2 Pa

Overall dimensions of the speaker... 360x710x285 mm

Speaker weight no more than... 30 kg

S-90 is a classic of Soviet column construction. According to the manual, the S-90 speaker system is designed for high-quality reproduction of sound programs in combination with various types household radio equipment.

Well, for the early 80s these were truly outstanding speakers with high sound quality. However, foreign speaker construction is developing, and already at the beginning of the new century, the sound of the S-90 is perceived differently.

High frequencies sound disgusting, there is simply NO midrange! And if we talk about bass, then a similar effect will be when placing a healthy bass player in a large kick drum... The lows drone on in black. It is impossible to listen to D&B style music; IDM also hits the ears. What can we say about classics and calm music. After an hour or two of listening, my ears begin to hurt (however, my head and stomach hurt no less). Despite these shortcomings, many people buy these speakers.

All of the following applies to Radiotechnika S-90a (AC35-212) speakers. This is one of the very first releases (and one of the best), characteristic features- 2 controls on the front panel, the tweeters and midrange are shifted from the center, the speakers are paired, the resistance is 4 ohms. However, the meaning of the modification and the modification itself can easily be applied to other S-90 (S-90b, S-90F, etc.), their analogues (Orbit, Amphiton, etc.), as well as to homemade speakers . Main criterion- the presence of 3 bands (speakers) and a bass reflex. The modification of speakers with a closed cabinet (i.e. without a bass reflex) is somewhat different, I will write about this later. And one more thing - there are many options for improvement, so in some places I will describe 2 methods. You will choose the most suitable one yourself..
I will not write a list of necessary materials - in most cases, everyone uses what is most available at the moment.

1) Disassembly

We take one speaker and place it on the floor with its back wall (this is the most convenient way to remove the speakers). Using a figured screwdriver, unscrew the 6 bolts securing the decorative plastic trim from the bottom of the column. Using a flat-head screwdriver, unscrew 4 bolts and remove the decorative nameplates from the speakers and the protective grilles.

Next, you will need a heated soldering iron! Then we unscrew the 4 bolts securing the woofer and carefully lift one side of it and remove it from the housing. We unsolder the wires (you can, of course, mark which one was soldered where - but better later check the diagram and solder it 100% correctly) and put it aside. We remove the midrange speaker from the housing (it was secured with a nameplate) along with the glass in which it stands. Unsolder it and put it to the woofer. We take out the HF (tweeter) - it was also attached with a nameplate and unsolder it. If there is no mark on it at one of the terminals (+), we mark which wire was soldered where, then we look where it goes according to the diagram and find “+”. We put it with the other speakers.

Be careful with diffusers! The speakers can only be grasped by the magnet or diffuser holder supports!!!
Unscrew the 4 screws on the bass reflex and carefully remove it from the housing. It is held on by sealant, the main thing here is not to use excessive force - it may break! We take out 2 “sausages” of cotton wool from the body (if it is there). We unscrew and remove the filter from the housing (it can be either on an iron chassis or on a wooden plank). The wires going to it can be cut off with wire cutters (they still need to be replaced early). That's all with disassembly! Now we need to finalize and assemble.

2) Modification of the case - it is advisable to strengthen the back side of the case with wooden slats (attached with screws and epoxy). It is also necessary to place a wooden spacer in the center of the speaker (between the rear wall and the front) at the level of the midrange glass. (the main thing is to pay attention to the possibility of then installing a bass reflex!!!) This is necessary to reduce vibrations of the body - turn it up louder and put your hand on it - the body shakes! You also need to check the tightness of the housing at the joints and, if necessary, coat the joints with epoxy glue or sealant.

3) Refinement of the filter: You will need a diagram.

The point is to remove switches from the circuit, replace the wires with audio made of oxygen-free copper, solder the speakers directly to the filter, solder the lead wire directly to the filter and shorten the signal path

In the absence of finances, you can also supply suitable copper ones from the Soviet Union. The point of selecting wires is multi-core for the woofer, with a cross-section of less than the more - the more better (but not less than 2.5 mm2, and more than 4mm2 is bad to solder), to the midrange you can have a multi-core of at least 1.5 mm2, and to the HF - a single-core of at least 1 mm2 (I recommend using a core from a twisted pair cable of the fifth category at + and at -). It should be said that the selection of wires is a delicate matter. There are still fierce discussions about the choice of wire for speakers. I express my personal opinion. I advise you not to skimp and buy at least the cheapest audio cable! The sound quality greatly depends on it! Take my word for it.

I also highly recommend remounting all the filter parts on a small piece of plywood/wood, so that you can place the filter on the bottom of the speaker, next to the bass reflex. This is important (especially if the filter is mounted on an iron plate). The inductors should be attached to the new board not with iron screws, but with something plastic or mounted on epoxy. So, we replace all the wires on the filter board - we install it directly to the outputs of the capacitors, removing the contact plates from them.

I will not give the sequence for replacing the wires. As well as tips on where to solder the wires from the bass, midrange and treble. I hope you figure it out :). If you can’t cope, invite knowledgeable person(one that can distinguish a capacitor from a resistor will do). As a last resort, write to me by e-mail [email protected]. We're done with the filter - put it aside.

4) Hull damping:

The point is to, if possible, absorb and dissipate all standing waves inside the housing. The criterion for choosing a material is that the denser and thicker it is (felt), the better it absorbs; the thinner and lighter it is (sintepon), the worse it is. The best way to make a pancake is to coat the body with sound-absorbing mastic (automotive mastic will do), then glue a layer of felt under 1 cm + the low-frequency part with another such layer and stick chaotically pieces of felt on top. They also recommend covering it with a layer of material for kitchen hoods - I don’t know, I haven’t seen it. I did this myself - everything is upholstered with 1.5 cm felt + the bottom part is another 1.5 cm + pieces. The sound absorber must be glued throughout the entire inside of the housing. After installing the first layer of felt, I recommend placing a filter board (with wires soldered to it) and a bass reflex port on the bottom of the speaker (otherwise you won’t be able to put it in later!), placing the remaining layers of sound absorber while closing the filter. and also wrap the bass reflex with a sound absorber (the main thing is not to cover the internal section of the pipe and maintain direct access from the bass diffuser to the bass reflex). Need to look behind internal volume body - you can’t reduce it too much - it will affect the depth of the bass! The body is finished.

By the way, I advise those who want to find household felt, about 1.5 cm thick.

5) Midrange speaker and its glass.

I highly recommend replacing the standard 15GD-11A (or its clone) with a broadband 6-GDSH-5-4 or 6-GDSH-5-8. The difference between them is that the first has a resistance of 4 ohms, and the second has 8 ohms. Accordingly, when installing 6-GDSH-5-8, the filter does not need to be changed, and when installing 6-GDSH-5-4, put a 4 Ohm large resistor (6-10 W) power. Resistor R3 (4.3 Ohm) from the midrange divider (columns 35AC212) is just suitable for this. Don't worry about losing power with this swap! You will only benefit in sound quality. The method has already been tested on many S-90s, there are no negative reviews, the power has not decreased. Moreover, competitors for the 6-GDSh-5 still need to be looked for (even among foreign analogues). And this is when the cost of a pair of these broadband speakers (new!) is $4-6. They have only one minus - appearance. Although I like it :).

For the midrange you need to make a PAS. This means covering the windows of the diffuser holder on the back of the speaker with a layer of foam rubber 0.5-0.8 cm thick. Quilted batting will also work. It is convenient to cut a strip of foam rubber 4-5 cm wide and a length equal to slightly less than the perimeter of the speaker, sew it and stretch it over the windows (for 15GD-11A). Then sew with threads to the supports. We made a PAS (be sure to do it - it degrades the quality factor, which is vital for almost all Soviet midranges used in the S-90 15GD11, and even more so!) - you can install the glass and speaker in place. Insert the glass into the body and wrap the outside in 2-3 layers of a good, dense sound absorber. It is convenient to cut off a boot boot that is suitable in height and width from a felt boot, place it in the body, and then place a glass of midrange in it. The inside of the glass also needs to be covered with a layer of sound absorber (felt is just right). The purpose of such damping is to eliminate the influence of the low-frequency head on the midrange. Then you need to put fluffy cotton wool in the glass and you can put the midrange speaker in place. First check that its phasing is correct.

When you connect a 1.5V AA battery + to + the speaker, a - to - , the diffuser moves forward. Checking phasing is important! We solder the wires to it (+ according to the diagram to + on the speaker) and place them in the housing through the rubber gasket, between the midrange and the glass. Rubber 2-3mm thick. It is convenient to use window rubber insulation made in the form of hollow tubes and with a self-adhesive side.

We install the speaker, seal it with plasticine and screw it on top with a nameplate, placing rubber gaskets on the screws between it and the speaker. It is better not to install a protective grille - it spoils the sound. Have you seen good imported speakers with grilles on the speakers? When installing 6-GDSH-5 under the nameplate, you will need to put rubber gaskets about 1 cm thick on the screws.

More about the midrange speaker. If you don’t want to install another midrange driver, you can modify the old one, for example like this. Although if you have a speaker with a rubber, rather than fabric, surround, it’s better to go for the 6GDSH!

6) Vata:

This sweet word is cotton wool... It greatly affects both the overall sound and the bass in particular! So one day I reduced its amount by half. The speakers began to emit not bass, but some kind of hum...

So, we sew a couple of gauze bags (35 cm by 35 cm) and fill them with cotton wool from the 2 sausages that were removed from the body, so that almost the entire sausage goes into the first bag, and less than half of the second into the second bag. Fluff the cotton wool. We place these bags in the upper part of the case under the slot for

HF and next to the midrange glass. We fluff the remaining half of the cotton sausage and simply throw it on the bottom of the column, on the filter wrapped in felt. In my opinion, this is the best placement of cotton wool in these columns.

7) HF head.

Solder according to the diagram. We put it into the body through a rubber gasket and screw it on top with a nameplate. We also don’t install a protective grille!
Uhh... A hell of a job has been done, but there is very little left! Let's continue.

8) woofer.

We solder it (it is advisable to check the phasing, as well as the midrange) and place it through a rubber gasket (required!), fasten it with bolts, again through rubber washers and seal it with plasticine sealant. We put a nameplate on top.

9)End of assembly.

We install the plastic front, tighten all the bolts and wipe the front panel.

Yes - a few little things (quite important!): run the wires to the HF and MF under a layer of sound absorber, and wrap them around the LF; carefully check the phasing, keep in mind that the bass and midrange in the S-90 are connected in antiphase; be sure to place the speakers on rubber pads; remove all parts from the plates of the disconnected HF and MF dividers, and cover them with a sound absorber; don't skimp on wires; remove the grilles; do not suffocate the volume; the bass reflex pipe must communicate freely with the surface of the speaker diffuser; gauze is clamped inside the bass reflex pipe - it is needed there; place the speakers on spikes (for example like this); It is better to immediately solder the connecting cable to the filter; it is much cheaper than buying good connectors.

Acoustic design

Speaker design features that have a direct impact on sound quality. Possible options acoustic design : bass reflex type, closed type, open type, with passive radiator, . The body of a closed-type acoustic system is a hermetically sealed box with a speaker diffuser (sound emitter) located on the front panel. The disadvantages of such acoustics are low sensitivity, not very deep bass, the advantages are simplicity of design and good transient characteristics, which guarantee a low level of distortion and accurate sound reproduction. Speakers with a bass reflex have a closed housing, on one of the walls or at the bottom of which there is an output hole (or port) of the bass reflex, connecting the internal volume of the speaker system with the outside world. The bass reflex itself is a tube of a certain length, selected so that the sound wave emitted by the rear side of the diffuser is reversed in phase and exits through the port. As a result, sound waves from the rear and front surfaces of the diffuser are added, increasing the sound pressure level of the loudspeaker. The advantages of such acoustics are high sensitivity, reproduction of the deepest bass, and small sizes (compared to similar closed-type speakers). Disadvantages - poor transient response, which manifests itself in practice as a slight “smearing” of the sound. A type of bass reflex type speaker is a speaker with a passive radiator, or “passive radiator”. In design, they resemble speakers with a bass reflex, but instead of it a passive radiator is installed in an additional hole. It is part of a low-frequency loudspeaker without a coil and a magnetic system and performs the same role as a bass reflex. The passive radiator is selected so that its resonant frequency is equal to the lower operating frequency of the loudspeaker. This improves the reproduction of low frequencies. This design is often used in subwoofers. One of the advantages of a passive radiator over speakers with a conventional phase reflex is the absence of air flow noise in the resonator pipe. Open-type speaker systems are very rare; in them, the housing is a thick panel in which the speakers are installed. Such loudspeakers provide dipole-type acoustic radiation (see “Acoustic radiation”), that is, sound vibrations from the speaker propagate both from the front and from the rear. Due to the fact that there is practically no housing in such speakers, all negative vibrations that arise during resonance in speakers with a “regular” housing are minimized. "Open" speakers can be installed close to the wall, since the sound practically does not travel laterally. Open-type speakers have a weakened reproduction of low frequencies, so manufacturers have to install very large woofers (much larger than in closed speakers or speakers with a bass reflex). Bandpass or strip body contains elements of a closed box and a body with a bass reflex. This housing is divided into two parts by a partition. One part is completely closed, and the second has access to the outside in the form of a bass reflex tunnel, through which the bass is supplied outside in a concentrated form. The low-frequency speaker is mounted on the partition. The main advantage of a strip housing is high efficiency. In other words, a speaker installed in a bandpass will sound louder than the same speaker installed in a closed enclosure. In addition, the subwoofer in a bandpass housing produces sound in a narrow low frequency band. Most modern speaker systems use a bass reflex design.