Games

S90 body dimensions. Speakers S90 scheme, description

Small cabinet volume for a woofer. The consequence is the humming of low frequencies.
The phase inverter is designed for a frequency of 20 Hz. The consequence is large bass distortion.
Worthless mid-range speaker. The consequences are disgusting midrange, overtones.
low frequency tweeter resonance. Consequences - "quacking", hissing.
The filter is designed taking into account the previous shortcomings. The consequence is that when modifying any node, the filter must be changed.
The case is not rigid enough and is not "muffled". Consequences - vibrations, overtones, "barrel".
Etc. etc. …

Learning and laughing

Drinking beer, we reach three truths. There are three ways:

Lightweight and efficient.
Medium difficulty. More shamanism and snobbery. Some sound improvements compared to point 1.
Super complex, time consuming and super efficient. You are actually trying to make new speakers. It all depends on the quality of workmanship and musical flair. If nothing happens, then no one promised you anything.

Attention! Attention! Attention!

When carrying out all work, make sure that the phasing of the speakers is correct. If you have not encountered this yourself - invite a specialist - electronics!
Alteration of the speaker 15 GD - 11A is an irreversible process. In case of inaccuracy, the speaker has one road - to the trash can, and you have another - to the market.

Way one. Lightweight and efficient.

The mids are the main focus. By altering the speaker, we will achieve its operation in piston mode, increase the upper cutoff frequency, remove overtones, increase sensitivity, improve directivity, dampen.
Let's translate the column into the range from 31.5 Hz, instead of 20 Hz. There will be less noise.
We will suppress the resonance of the high-frequency head.
Calm down the overtones of the hull

We buy a Soviet tennis ball in the store. Chinese and others do not fit. They have different material. The ball should be exactly the same as in early childhood for 8 kopecks. In extreme cases, you can take it from friends or in the sports section of tennis. We buy epoxy resin (a little, you can 1 cm cube), glue (Supercement, Mars, Argo, etc. - hard after hardening), a couple of simple pencils, any medical bandage and cotton wool.

Dilute epoxy with double the amount of hardener. Cover the surface of the ball with the thinnest layer. If necessary, excess glue can be removed with newsprint. Sprinkle with graphite, shake off excess. It is necessary to ensure that the white plastic of the ball does not shine through the graphite. If it shines through, then the epoxy layer was small. We must add. After everything turned out, we leave to harden.

We collect the filter at 3 kHz. To do this, we take a 4.7 Mf capacitor and a 0.6 mH inductor. You can take a capacitor from 4 to 7 mF and fit a choke under it. In order not to fill your head with unnecessary formulas, the simplest thing is that the product of the capacitance of the capacitor in microfarads and the inductance of the inductor in mH should be equal to 2.82. Let's say the capacitance of the filter capacitor is 6.6 μF (MBGO and MBM with a tolerance of ± 10% from the nominal value), then the coil inductance is 2.82: 6.6 = 0.43 mH, (the winding contains 150 turns of wire PEV-1 0.8 wound on a frame with a diameter of 22 and a length of 22 mm with a cheek diameter of 44 mm). Based on these data, it is possible to assemble a circuit without an LC meter, since it is not the exact value that is important, but the "capture" of the resonant frequency, which has a certain spread. We mount the capacitor and inductor on a piece of fiberboard and solder one output of the coil to the output of the capacitor. We solder wires 40-50 cm long to the free leads.

We parse the column. We remove the low-frequency speaker, mid-frequency speaker, take out the glass from it, remove the high-frequency speaker, remove the decorative overlay, remove the phase inverter (on some speakers you will have to unscrew the filter). We take half of the dried ball, polish it on the outside with suede or newsprint and glue it over the dust cap of the midrange speaker head with hard glue. It is necessary to ensure that there are no unglued lye between the edge of the ball and the cap and that the ball is glued exactly in the center. We do the same with the second midrange. We leave to dry.

We place the bandage along the wire and twist it, clasping the wire. It is convenient to fix the bandage with threads. We collect the column. We coat with plasticine all the perimeters of all the speakers. put on protective nets not worth it, but only on the condition that there are no small children, the wife does not call in with a mop or vacuum cleaner, and that the speakers will not be transported. We turn on the columns. We don't know right. We call friends. Please come with your favorite entries. We listen. Comforting friends with beer. With a sneer, we notice how useful the bucks spent on the purchase of foreign rubbish would be useful to them.

Way two. Medium difficulty.

We do everything that is indicated in path 1, but do not collect the columns.

We will improve the properties of the body and kill overtones and "barrel"
Achieve better signal transmission
Hull sealing. We remove the influence of the body

So let's go. Strengthen the rear wall of the case by placing two rails with a section of 3x2 cm. vertically in full length at a distance of 15-20 cm from each other symmetrically, and attaching them with screws to the back wall. Pre-treat the attachment site with epoxy. It is necessary to take into account the possibility of installing a phase inverter later. Between the back and front walls, we install a spacer rail at the level of the midrange head, taking into account the possibility of installing a glass. We coat all the joints of the walls and corners from the inside with silicone glue such as "Bizon" or plumbing silicone putties. We paste over the entire body inside with felt (batting, synthetic winterizer, etc.). Thicker than 1.5 cm is not worth it, so as not to greatly reduce the internal volume of the case.

We reject all proposals to change 15 GD - 11A to 6 GDSH-5. Ours is already "cool", and such a replacement will lead to a loss of power, a decrease in dynamic range (very dangerous) and you will have to change the filter a lot. So when replacing 15 GD - 11A with 6 GDSH-5 for 35AC - 212, you will have to replace the following parts: L1 - 0.22mH, C2 - 1.0mF, C8 - 0.5mF, L4 - 0.1mH. New parameters are specified. When using 6 GDSH - 5 - 4, you will also have to put additional resistance in the circuit of this head at 4 ohms. Also, the appearance of the column changes. Well, if you really want to, then you can. Further. Remove tone switches. Remove unnecessary resistors R (1, 2, 4, 5, 7, 8, 9, 11, 12). We replace the wires on the filter installation with a copper wire with a diameter of 1.2 mm. We replace the wires going from the speakers to the filter with more travel ones. On a low-frequency speaker - stranded - with a cross section of 2.5 - 3 mm square, on a mid-frequency speaker - 2.5 mm square. On high-frequency - 2 mm sq. - single core. All wires are soldered to the filter directly, and not through the previous speakers. The filter is installed at the bottom of the column. All wires are laid under a layer of felt. On the side walls.

The filter controls are removable. We make wooden (chipboard, plywood) plugs in their place according to the thickness of the body. We pour them on epoxy and grind them. We cover the front panel with self-adhesive wood-like film to match the veneer of the speakers. Installing speakers. Low-frequency and mid-frequency through rubber pads. Suitable rubber from window insulation, thin rubber medical hoses, silicone hoses (worse). We process the installed speakers around the perimeter with plasticine or non-hardening window putty (it resembles a piece of laundry soap and is cheap). Checking the sound. We're just balding. Pushing back all sorts of "Pioner", "Technics", JAMO and ...

Way three. Super complex, time consuming and super efficient.

It is good to have the following instruments: oscilloscope, generator audio frequencies, digital multimeter, LC meter. A person who does not repair and assemble at home - of course, does not have all this, but there is a way out - go to the workshop and ask to measure what you need, taking filters, heads, etc. with you. If they ask for a fee for this, then it is purely symbolic. You can even order filters. This, of course, will be more expensive. Let's start. We take as a basis 35AC-212 with dimensions 710x360x285. It is desirable that the case be plywood, a woofer with a rubber suspension, a tweeter with a fiberglass dome. We understand everything. We no longer need a midrange speaker. The case must be increased for a low-frequency speaker with a rubber suspension up to 100 liters. If the suspension is polyurethane foam, then up to 120-130 liters. Our body is 70 liters.

There are two options:

Remove the front wall from the case, so that later it can be used for the matrix for the holes for the speakers in the newly manufactured case for 100 liters. From the remains of the buildings, good boxes are obtained for potatoes and markoshka in the cellar.
You can try to build up the old building.

In the first case, you need to focus on the dimensions - 1100x360x350 and manufacturing in a furniture workshop according to your drawings, with swearing and nitpicking about quality. We will consider the second way. So, you can try to get by with little bloodshed. We make it ourselves, or we order two boxes with tightly fitting walls and lids made of double 10-layer plywood with external dimensions - 380x360x285. In the bottom of the column and in the lid of the box, we cut out the same holes of approximately 270x210. Cover the inside of the box with felt. After assembly, it will be unrealistic to do this. We drill holes in the lid of the box and in the bottom of the column through which we fasten them together with bolts. The heads of the bolts should sink into the potai. Falling asleep a little - 10 kilograms of shot does not hurt, we throw a gauze bag with cotton wool on top. Pre-spill the connection with epoxy with a normal hardener content. We glue the junction with felt. The rest of the movements with the body, as in paths 1 and 2. We take the mid-frequency head 30 GDS-1. You just need to check them - a lot of marriage. Purely mechanical property. Further. We measure the resonance f of all speakers. You can sign with a felt-tip pen directly on the magnets so as not to get confused and not to measure everything again.

It would be nice if the resonance frequency of the paired speakers did not differ much. If the speaker emits extraneous sounds at any of the audio frequencies, then it must either be cleaned or changed if cleaning failed to achieve normal operation. We calculate and make filters for our case. The fewer inductances, the better. We continue to deal with the body. We remove excess resin at the junction. We grind it. We make two wooden boxes for filters. We will mount them on the back wall from the outside. We solder the wires from the amplifier directly to the filters. And we will drag the wires to the speakers through the fastening of the speaker connectors. All wires are branded audiophile. Price category choose yourself. Just take very expensive ones - it makes no sense. It is better to convert the phase inverter to a frequency of 31.5 - 40 Hz. If the dome of the high-frequency head is made of lavsan, then, having removed the cross, it is necessary to coat the suspension and the outer third of the dome with perchlorovinyl. We paste over the entire body with a self-adhesive film. For the rest, see path 1 and path 2. With mandatory step-by-step verification - better - worse. The best method, if there is no obvious result, is blind listening.

Literature

Zhagirnovsky M., Shorov 8. Improving the sound of 35AC-1 and its modifications. - Radio, 1987, No. 8, p. 29, 30.
Shorov V. Improvement of loudspeaker heads. — Radio. 1986, no. 4, p. 39-41.
Aldoshina I., Voishvillo A. High-quality acoustic systems and emitters. — M.; Radio and communication. 1985.
Zhbanov V. Mechanical damping of diffusers. - Radio, 1988, No. 5, p. 41-43.
Maslov A. Once again about the alteration of the loudspeaker 35AC-212 (S-90). - Radio, 1985. No. 1, S. 59.
Zhbanov V. On the damping of dynamic heads. - Radio, 1987, No. 8, p. 31-34.
Gennady and Karen Arzumanov. To the question of the modernization of acoustic systems. Vestnik A.R.F. №6" 2000

Actually there are four ways, not three. But the first way - to throw away - we will not describe. In our country house and in the garage, there are so many good things ...
The main disadvantages of the S-90 series speakers.
1. Small cabinet volume for the woofer. Consequence - mumbling of low frequencies.
2. The phase inverter is designed for a frequency of 20 Hz. The consequence is a large distortion of the bass.
3. Useless midrange speaker. Consequences - disgusting midrange, overtones.
4. Low frequency tweeter resonance. Consequences - "quacking", hissing.
5. The filter is designed taking into account the previous shortcomings. Consequence - when modifying any node, the filter must be changed.
6. The case is not rigid enough and is not "muffled". Consequences - vibrations, overtones, "barrel".
7. Etc. etc. …

Learning and laughing

Drinking beer, we reach three truths. There are three ways:
1. Lightweight and efficient.
2. Medium difficulty. More shamanism and snobbery. Some sound improvements compared to point 1.
3. Super complex, labor intensive and super efficient. You are actually trying to make new speakers. It all depends on the quality of workmanship and musical flair. If nothing happens, then no one promised you anything. I will describe everything. I recommend to start with the 1st way. Its value is that it does not take much time, you leave all the components of the columns. Minimum scarce parts and costs.

ATTENTION! ATTENTION! ATTENTION!

1. When carrying out all work, make sure that the phasing of the speakers is correct. If you have not encountered this yourself - invite a specialist - electronics!
2. Alteration of the speaker 15 GD - 11A - the process is irreversible. In case of inaccuracy, the speaker has one road - to the trash can, and you have another - to the market.

Way one. Lightweight and efficient

1. Mid frequencies - the main focus. By altering the speaker, we will achieve its operation in piston mode, increase the upper cutoff frequency, remove overtones, increase sensitivity, improve directivity, dampen.
2. Let's move the column to the range from 31.5 Hz, instead of 20 Hz. There will be less noise.
3. We will suppress the resonance of the high-frequency head.
4. Calm down the overtones of the body

Let's get creative. We cut the ball in half along the seam. The seam is visible through the light. It is overlapped and 1 - 2 mm wide. You need to cut in the middle of the seam. I sawed with the Neva blade, having previously made notches on it with a whetstone. After sawing, align the cut line on sandpaper, and process the outer surface of the ball with fine sandpaper. If there are large influxes inside in the area of \u200b\u200bthe seam, then they must also be removed. When working, the ball must be fixed with plasticine on the Mars battery (case from photographic film, jars of fish food, etc., by imagination) at three points. It's enough. Plasticine is removed with sweat or with a dry cloth or rubbing with gasoline. After the surface of the ball is processed, it should not be touched by hands. Grind pencil leads on sandpaper. Dilute epoxy with double the amount of hardener. Cover the surface of the ball with the thinnest layer. If necessary, excess glue can be removed with newsprint. Sprinkle with graphite, shake off excess. It is necessary to ensure that the white plastic of the ball does not shine through the graphite. If it shines through, then the epoxy layer was small. We must add. After everything turned out, we leave to harden.

We fasten a home-made filter to the back wall of the speaker (inside) opposite the tweeter. Solder the wires from the filter to the output of the tweeter. Which one does not play a role. We remove the connectors from the rear wall of the speakers and solder the wire coming from the amplifier directly to the filter. From the pipe of the phase inverter we saw off with a hacksaw for metal 10 cm along the center line. We wrap the phase inverter pipe and the glass of the midrange speaker with a layer of gauze and bandage it. It is necessary to check whether they will enter their nests after this procedure. If not included, then reduce the layer of cotton wool with gauze. We check if there is cotton wool and gauze in the glass. Add if little to complete. We dampen the midrange speakers. To do this, we additionally fit their diffuser holders with foam rubber rings made from blanks 10x27x355 mm. the ends of which are glued together with glue "Moment" end-to-end. We glue the bottom and ceiling of the column from the inside with felt (batting, padding polyester, etc.). We wrap the wires with a bandage. We place the bandage along the wire and twist it, clasping the wire. It is convenient to fix the bandage with threads. We collect the column. We coat with plasticine all the perimeters of all the speakers. It is not worth putting on protective nets, but only on the condition that there are no small children, the wife does not call in with a mop or vacuum cleaner, and that the speakers will not be transported. We turn on the columns. We don't know right. We call friends. Please come with your favorite entries. We listen. Comforting friends with beer. With a mockery, we notice how useful the bucks spent on the purchase of foreign rubbish would be useful to them.

Way two. Medium difficulty

We do everything that is indicated in path 1, but do not collect the columns.

1. Improve the properties of the body and kill overtones and "barrel"
2. Achieve better signal transmission
3. ?

So let's go. Strengthen the rear wall of the case by placing two slats with a section of 3x2 cm vertically in full length at a distance of 15 - 20 cm from each other symmetrically, and attaching them with screws to the back wall. Pre-treat the attachment site with epoxy. It is necessary to take into account the possibility of installing a phase inverter later. Between the back and front walls, we install a spacer rail at the level of the midrange head, taking into account the possibility of installing a glass. We coat all the joints of the walls and corners from the inside with silicone glue such as "Bizon" or plumbing silicone putties. We paste over the entire body inside with felt (batting, synthetic winterizer, etc.). Thicker than 1.5 cm is not worth it, so as not to greatly reduce the internal volume of the case. We reject all proposals to change 15 GD - 11A to 6 GDSH-5. Ours is already "cool", and such a replacement will lead to a loss of power, a decrease in dynamic range (very dangerous) and you will have to change the filter a lot. So when replacing 15 GD - 11A with 6 GDSH-5 for 35AC - 212, you will have to replace the following parts: L1 - 0.22mH, C2 - 1.0mF, C8 - 0.5mF, L4 - 0.1mH. New parameters are specified. When using 6 GDSH - 5 - 4, you will also have to put additional resistance in the circuit of this head at 4 ohms. Also, the appearance of the column changes. Well, if you really want to, then you can. Further. Remove tone switches. Remove unnecessary resistors R (1, 2, 4, 5, 7, 8, 9, 11, 12). We replace the wires on the filter installation with a copper wire with a diameter of 1.2 mm. We replace the wires going from the speakers to the filter with more travel ones. On a low-frequency speaker - stranded - with a cross section of 2.5 - 3 mm square, on a mid-frequency speaker - 2.5 mm square. On high-frequency - 2 mm sq. - single core. All wires are soldered to the filter directly, and not through the previous speakers. The filter is installed at the bottom of the column. All wires are laid under a layer of felt. On the side walls. The filter controls are removable. We make wooden (chipboard, plywood) plugs in their place according to the thickness of the body. We pour them on epoxy and grind them. We cover the front panel with self-adhesive wood-like film to match the veneer of the speakers. Installing speakers. Low-frequency and mid-frequency through rubber pads. Suitable rubber from window insulation, thin rubber medical hoses, silicone hoses (worse). We process the installed speakers around the perimeter with plasticine or non-hardening window putty (it resembles a piece of laundry soap and is cheap). Checking the sound. We're just balding. Pushing back all sorts of "Pioner", "Technics", JAMO and ...

Way three. Super complex, time consuming and super efficient

It's good to have the following instruments: an oscilloscope, an audio frequency generator, a digital multimeter, an LC meter. A person who does not repair and assemble at home - of course, does not have all this, but there is a way out - go to the workshop and ask to measure what you need, taking filters, heads, etc. with you. If they ask for a fee for this, then it is purely symbolic. You can even order filters. This, of course, will be more expensive.

Begin. We take as a basis 35AC -212 with dimensions 710x360x285. It is desirable that the case be plywood, a woofer with a rubber suspension, a tweeter with a fiberglass dome. We understand everything. We no longer need a midrange speaker. The case must be increased for a low-frequency speaker with a rubber suspension up to 100 liters. If the suspension is polyurethane foam, then up to 120 - 130 liters. Our body is 70 liters. There are two options:

1. Remove the front wall from the case, so that later it can be used for the matrix for the speaker holes in the newly manufactured 100 l case. From the remains of the buildings, good boxes are obtained for potatoes and markoshka in the cellar.
2. You can try to build up the old building. In the first case, you need to focus on the dimensions - 1100x360x350 and manufacturing in a furniture workshop according to your drawings, with abuse and nit-picking about quality. We will consider the second way.

So, you can try to get by with a little blood. We make it ourselves, or we order two boxes with tightly fitting walls and lids made of double 10-layer plywood with external dimensions - 380x360x285. In the bottom of the column and in the lid of the box, we cut out the same holes of approximately 270x210. Cover the inside of the box with felt. After assembly, it will be unrealistic to do this. We drill holes in the lid of the box and in the bottom of the column through which we fasten them together with bolts. The heads of the bolts should sink into the potai. Falling asleep a little - 10 kilograms of shot does not hurt, we throw a gauze bag with cotton wool on top. Pre-spill the connection with epoxy with a normal hardener content. We glue the junction with felt. The rest of the movements with the body, as in paths 1 and 2. We take the mid-frequency head 30 GDS - 1. We just need to check them - a lot of marriage. Purely mechanical property. Further. We measure the resonance f of all speakers. You can sign with a felt-tip pen directly on the magnets so as not to get confused and not to measure everything again. It would be nice if the resonance frequency of the paired speakers did not differ much. If the speaker makes extraneous sounds at any of the audio frequencies, then it must either be cleaned or changed if normal operation was not achieved by cleaning. We calculate and make filters for our case. The less inductance, the better. We continue to deal with the body. We remove excess resin at the junction. We grind it. We make two wooden boxes for filters. We will mount them on the back wall from the outside. We solder the wires from the amplifier directly to the filters. And we will drag the wires to the speakers through the fastening of the speaker connectors. All wires are branded audiophile. Choose your price range. Just very expensive to take - it makes no sense. It is better to convert the phase inverter to a frequency of 31.5 - 40 Hz. If the dome of the high-frequency head is made of lavsan, then, having removed the cross, it is necessary to coat the suspension and the outer third of the dome with perchlorovinyl. We paste over the entire body with a self-adhesive film. For the rest, see path 1 and path 2. With a mandatory step-by-step check - better - worse. The best method, if there is no obvious result, is blind listening.

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No matter what the snobs say, the Soviet ones were really high level. Even now they can bypass many modern "tweeters". And after appropriate refinement, even budget speaker systems from Yamaha cannot be compared with them. And now we will look at the legendary Radiotehnika S90. This is a symbol Even abroad noted the high quality of this (at one time). Therefore, it makes sense to consider these columns. Moreover, many people use them to this day.

A bit of history

Radiotehnika S90 speakers were first released in the early eighties of the last century. They were produced by a plant located in Latvia, which became an additional incentive for citizens to buy them. Despite the rather high price, the speakers sold like hot cakes. People saved for a long time, malnourished, hiccupped them wherever possible. They even bought used speakers. If only to decorate their closets with "Radio Engineering".

Nowadays, many audiophiles are still chasing this speaker system. Speakers "Radio engineering" - the blue dream of every connoisseur of high-quality sound. But now they can only be purchased on the secondary market. And it is far from a fact that their condition will be acceptable (however, this acoustic system can give odds to many modern speakers. And after the appropriate refinement, it completely turns into Hi-End class acoustics. And this is a completely different level.

Appearance and design

Looks impressive from Radio Engineering. These are very large speakers. Each of them weighs about 15-20 kilograms. This is not to mention the fact that it is not very convenient to carry them because of the bulky and voluminous case. The front panel (as well as the entire body) is covered with veneer. There are several color combinations. The speakers are covered with a metal mesh. Only the tweeter is not covered by protection. This, of course, is good, but it does not affect the acoustic properties of the speakers in the best way. However, the design is quite acceptable. Much better than other "clumsy" Soviet-made columns.

On the right side of the midrange and tweeters are two mode switches. It is not known why they were placed here. A normal amplifier itself is able to switch modes. And the work of the speakers is to reproduce the sound correctly. Nevertheless, in Radiotehnika S90 such switches are available. But in the process of refinement, they can be removed, because they affect the overall sound quality very negatively. But for those who appreciate retro and antiques, such proposals will seem like blasphemy.

Specifications

So, let's move on to the mean numbers. The normal power of the speakers is 35 watts. But these handsome men can easily give out 90. That is why they were called "the nightmare of the neighbors." However, for their full disclosure, appropriate power stereo amplifiers. Only then will this speaker system sound for real. The frequency range starts at 20 hertz and ends at 25,000 hertz. Such a wide range allows the speakers to reproduce almost all instruments quite reliably. Frequency response is quite acceptable for a speaker system given level. No miracles can be expected from her. But the sound is quite decent.

Now the most interesting part is the subwoofer. This is the legendary "Dean 75 GD". The thing, of course, is good, but it does not produce an ideally reliable bass. If the woofer is at least something of itself, then the mid-range and woofers, although they cope with their task, but it will not work to call them "kosher". Ordinary paper "bubbles". It would be much better to replace them with Kevlar or silk domes during refinishing. That's when the big speakers will sound. Yes, and it is better to rewind the woofer, since in used speakers it is often burned out due to "super-mega bass".

Sound quality

As mentioned above, the Radio Engineering speakers with standard components cannot boast of a very clear and correct sound. But the quality is enough for not very demanding listeners. The acoustic system does an excellent job with instrumental music (light rock, jazz, blues), the electronic one is also good at it. But heavy and other sub-genres of great and terrible metal - not so much. That is, the speakers reproduce it as expected, but the woofer twitches so that it can easily break. Especially when listening to those groups that often abuse the cardan on the "barrel".

The classic is also good. This is probably the only genre that the Radiotehnika S90 handles perfectly well. All instruments sound crystal clear. Nothing moves forward. Listening to the classics on these speakers may well appeal even to audiophiles. However, to call this speaker system a Hi-End level thing will not work. To achieve this level, the columns will have to be finalized. As standard, this is an average but confident Hi-Fi. And the Soviet people did not need more.

Amplifiers for S90

In order for passive acoustics to sound good, you also need quality amplifiers stereo. It should be noted that the "nineties" is able to shake and fully reveal only very powerful amplifier. The Soviet machines "Brig" and "Odyssey" will perfectly cope with such work. These monsters are capable of squeezing everything out of the speakers. "Amfiton U-001" will also do well. Just do not try to connect this speaker system to the Vega 50U. The amplifier will immediately refuse to work even at the minimum volume.

The ideal option for this speaker system is the Radio Engineering amplifier. They were produced in huge batches, with different power and resistance. Therefore, finding such a thing in the secondary market is not a problem. There are more than enough suitable amplifiers of such a plan. You can, of course, puzzle yourself and connect these speakers to a very modern receiver like Yamaha. But then such a kit will go far beyond the "budget". Yes, and such a decision is not worth the candle. It's like putting a Porsche engine into a Zaporozhets. It's possible, but it doesn't make sense.

S90 price

Now let's analyze the most interesting quality of Radiotehnika S90. The price in the secondary market depends on the "kill" of the kit and its originality. Speakers as standard and in good condition will cost from 1000 to 2000 rubles. Depending on how good they look. Speakers with a whole internal system cost almost the same. You can even find almost unused ones. It all depends on the seller and the degree of awareness of the buyer. Columns modified in accordance with all the rules will cost more, since this is an acoustic system of a completely different class. They will cost about 3000 rubles.

The Radio Engineering amplifier will also cost about the same amount. Such monsters as "Brig" or "Odysseus" in perfect condition will cost about 15,000 rubles. But the problem is that finding them is almost impossible. The total approximate cost of a complete set will be approximately 6,000 rubles. Much better than the incomprehensible Chinese speaker system for the same money. However, this is an estimate. It may vary depending on the degree of refinement of the speaker system and its condition. But it still works out much better. And the sound quality will be on the level.

Positive feedback from owners

Now consider the reviews of the Radiotehnika S90 speaker system. The amplifier is a separate topic, so we will not consider it here. So what will the owners say? Positive and negative reviews about these speakers go "nostril to nostril". Competent audiophiles have long finalized their "nineties" and therefore their reviews are laudatory panegyrics to the Soviet speakers. There is a clear sound, a clearly traced bass, a wide range, versatility (for all genres) with some equalizer settings. Also an important plus for many was a completely wooden case. And the power of these speakers is the talk of the town. Everyone noted this quality.

Negative owner reviews

However, there are snobs who are not satisfied with the sound quality of this speaker system. They note the insufficient drawing of the middle and high frequencies(and it is true). The case after so many years of use is already just rattling. The woofer thumps out of place. But, comrades, any thing must be monitored and timely preventive measures carried out. This also applies to columns. After the appropriate procedures, they will sound completely different. Dissatisfied owners of the S90 - take note!

Conclusion

Radiotehnika S90 is one of the most preferred budget options. It copes with its duties much better than any modern acoustics originally from China, lends itself perfectly to refinement and can provide Hi-End class sound. What else does a music lover need to be happy?

Video

Description

Acoustic system Radiotehnika S-90F

Radiotehnika S-90F - 3-way speaker system with bass reflex.
Release since 1980 at the Riga plant "Radiotehnika"

Designed for high-quality sound reproduction in standard household conditions.
"S-90F" is a speaker that meets the requirements of international documents for Hi-Fi category equipment. The difference between this modification of the AU from the S-90 is: in an extended frequency range, the introduction of an indication electrical overload loudspeakers and new appearance. The recommended power of the used amplifier is 20-90 watts.

Cases of all AC modifications are made in the form of a rectangular non-separable box made of chipboard, veneered with fine wood veneer. The wall thickness of the case is 16 mm., the front panel is plywood with a thickness of 22 mm. Elements are installed at the joints of the body walls from the inside, which increase the strength and rigidity of the body.

The speakers used the following set of heads manufactured by "Radiotehnika" software:

The heads included in the "S-90F" are each framed with decorative overlays and protected by a mesh; the location of the heads is similar to the location in the "S-90". On the front panel, in addition, there are: indicators of overloads of the loudspeaker heads, sound pressure level controls for the MW and HF loudspeaker heads, a nameplate with the name AC. There is a 95x75mm rectangular outlet at the bottom of the front panel. phase inverter, the tuning frequency of which is 31 Hz.
The internal volume of all AC modifications is 45 dm3. To reduce the influence of the frequency response of sound pressure and the sound quality of the AC resonances of the internal volume of the case, it is filled with a sound absorber, which is mats made of technical cotton covered with gauze. The mats are located and fixed on the inner surfaces of the body walls.
Inside the walls of the case, on one board, electrical filters are mounted that provide electrical separation of the bass, midrange, and high-frequency bands of the speakers. Electrical filters all modifications of the speakers have the same design and fundamental electrical circuits.
Section frequencies provided by filters: between LF and MF - 750 ± 50 Hz, between MF and HF - 5000 ± 500 Hz.
In the design of the filters and the overload indication unit, resistors of the VS, MLT, SP3-38B, S5-35V, PPB types are used; capacitors of type MBG0-2, K50-12, K-75-11 and inductors on cast plastic frames.
Removable decorative frame, included in the set "S-90", "S-90D" is covered with a knitted fabric with high acoustic transparency.
The scope of delivery includes 4 plastic feet, which can be attached to the base of the case if necessary.

Technical details:

Frequency range - 25 (-14 dB) - 25000 Hz;
- Sensitivity - 89 dB (0.56 Pa /? W);
- Uneven frequency response in the frequency range 100 - 8000 Hz: ± 4 dB;
- The directivity characteristic of the speakers, measured by the deviation of the frequency response of sound pressure at angles to the acoustic axis:
v vertical plane+2°: -4 dB
horizontal +4°: -3 dB
- Harmonic distortion at a sound pressure of 90 dB in the frequency range:
250 - 1000 Hz: 2%
1000 - 2000 Hz: 1.5%
2000 - 6300 Hz: 1%
- Resistance - 8 Ohm;
- Minimum impedance value -7 Ohm;
- Rated power - 90 W;

11-01-2009

Finalization of acoustic Radiotehnika systems 35AC-012 (S-90)

Radiotehnika 35AC-012, Radiotehnika S-90, Radio engineering 35AC-012, Radio engineering S-90

I am currently the proud owner of speakers Radiotehnika S-90.

Consideration of acoustics in normal condition

To begin with, the full name of acoustics should be specified - 35AC-012. From their issue, it immediately becomes clear that we are dealing with high-class acoustics, by Soviet standards, that is, acoustics with very high characteristics. It should be noted right away that by Soviet standards it was not the most best acoustics, but an ordinary ordinary workhorse. There were acoustics that had a more balanced sound, for example, the same Cleavers / Corvettes 35AC-008.

But as they say, we have what we have. Let's go back a little to the moment of their purchase. I took them from my friend for $ 50, when I came to him, when I saw the decorative grilles protecting the sound emitting heads, I wanted to cry, they were dented and very cruelly at that (mainly the grilles of the tweeter and mid-range speaker suffered). But this did not frighten me, since what was sold on our market cost at least $ 100, and the quality of the speakers deserved no more than 3, and in these speakers the speakers looked at 5. In general, I took these speakers to my home. When connected to an amplifier, the sound was quite decent. Nevertheless, two shortcomings should be noted, one of which is inherent in all 35AC-012, and, as it turned out, all of its 35AC clones, to one degree or another.

The first of the shortcomings that just killed me on the spot is an incomprehensible overtone during the operation of the woofer, very similar to the fact that something was stuck to the speaker from behind, and now this is something vibrating, as it turned out later, it was a drop of solder that stuck to diffuser with reverse side. The second drawback was precisely in the mid-frequency dynamics 15GD-11A - according to the old standard and 20GDS-1-8 according to the new one (these speakers went to in large numbers modifications for this reason, which one is extremely difficult for you to track). And again, a small digression, in which I will say that the differences in the standards are in the designation of power, that is, according to the old standard, the nominal power of the speaker was indicated, and according to the new standard, the nameplate power is indicated (from the sound engineering course:

The rated power of the speaker is such a power of the speaker, when summed up, it works with harmonic distortion levels not higher than the permissible
Passport power (often also called noise power): this is the level of power supplied to the speaker, at which the level of harmonic distortion is equal to ten times the level at rated power).

An additional division into the frequency ranges of the heads was also introduced, which was now indicated in the name of the speaker, in particular, this is the third letter.

So the disadvantage of this speaker is that it often starts to resonate at high volume and thereby spoils the sound picture, and as you know, the midrange speaker is crucial in shaping the sound picture.

Consider now in order all the speakers that we have available:

1)Low-frequency - 30GD2, aka 75GDN-1-4 (8):

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the highest complexity group as a low-frequency link when working indoors. Loudspeaker head of electrodynamic type, low-frequency, round, with unshielded magnetic circuit. The diffuser holder is made of die-cast aluminum alloy. The conical diffuser is made of impregnated paper pulp. Suspension - torroidal shape - made of rubber. The centering washer is made of impregnated fabric.

I also want to add that the speakers have a relatively heavy dome and a rubber suspension is used, which spoils the quality of the bass, it becomes more solid and booming than the speakers with a lighter mass of the moving part and a foam rubber suspension. But it should be borne in mind that the bass is affected not only by the design, but also directly acoustic design, for this reason, these troubles can be slightly eliminated and the speaker will play decently. On the other hand, due to the rubber suspension, the speaker turned out to be very reliable and practically unkillable, and the foam rubber suspension soon crumbles due to the presence of sulfur in the air and the speaker needs to be repaired.

Purpose - use in closed and phase-inverted remote acoustic systems of household radio equipment of the 1st and 2nd complexity groups as a mid-frequency link when working indoors. Loudspeaker driver of electrodynamic type, midrange, round, with unshielded magnetic circuit. The diffuser holder is made of die-cast aluminum alloy. The conical diffuser and the spherical cap are made of impregnated paper pulp. Torroidal suspension - made of polyurethane foam. The centering washer is made of impregnated fabric.

Here is actually a photo of this miracle of technology:

It should be said that at a good volume it decently distorts the sound, but as practice has shown this problem very easy to solve and very simple.

Purpose - the use in closed acoustic systems of household radio equipment of the highest complexity group as a high-frequency link when working indoors. Loudspeaker head of electrodynamic type, tweeter, round, with unshielded magnetic circuit. Mounting flange and acoustic lens are made of plastic. The dome-shaped diaphragm with a suspension is made on the basis of polyethylene terephthalate.

In general, they sound good, but the filter settings are close to resonant frequencies.

Upon closer examination of the acoustics (especially from the inside), you begin to be horrified by the build quality, for this reason we will begin to refine. We will refine it according to the simplest possible scheme, without interfering with the filters, since without specialized equipment there is nothing to do there. For those who are interested, here is the acoustics diagram:

Refinement 35AC-012

I will describe in order all the stages of improvement that my columns went through:
1. Disassembly:

First of all, we take them to a secluded place (meaning a room) in which our experimental subjects will not be available to children (if any) and other family members. We lay the speaker system on our back and begin to disassemble it.
Now remove the decorative trims from all the speakers and put them aside.

Here they are:

Then we get the speakers. ATTENTION When unscrewing the bass speaker (the tweeter and midrange speaker are attached with the same screws as the decorative trim, and the woofer is attached separately from the trim), be extremely careful, because if a screwdriver comes off, you will disfigure it. Then we solder the wires connecting the filter and the speakers with a soldering iron, and boldly hide the speakers in a secluded place.

We remove the phase inverter cover and pull out the phase inverter itself, and this must be done as carefully as possible, since we are working with plastic, and it can easily break. Then we hide these details in a secluded place.
Now we take on the regulator / regulators of the HF / MF links. To dismantle them, it is necessary to remove the decorative plug in the center of the regulator, then unscrew the opened screw and remove the regulator knob. After that, carefully pry off the remaining plastic lining with the help of two chisels and carefully remove it, then unscrew the 4 screws securing the attenuator itself and now it can be pushed out into the case. We push it out and solder it from the filter. We put it aside, in the future it will be necessary to conjure a little over it. By the way, the junction of the attenuator housing and the speaker housing is abundantly covered with a sealing viscous substance, I personally used it again when I assembled it in place, but you can use sealant or plasticine.
We take out the bags of cotton wool, which, in theory, lie in your speaker system and set aside.
We dismantle the panel with filters, it is screwed to the body, having previously unsoldered the wires from the output at the back of the speaker system. Putting it aside, as we will spend a lot of time working with them.
Finally, remove the panel with terminals from the rear cover of the speaker and set it aside.

It seems like a lot of work has been done, but in fact it is just a drop in the ocean. More interesting and labor-intensive work lies ahead.

2. Restore appearance:

For this purpose, we take the gratings and speaker covers we removed earlier, level them, carefully sand, degrease and paint several layers of automotive paint (which is in spray cans) several times and leave to dry. I’ll make a reservation right away that I restored the grilles only for the reason that I have a small child who can damage the speakers, in otherwise most simple solution there will be a rejection of the grilles as such, since they only bring minuses to the sound, then think for yourself.

3. Refinement of the speaker cabinet:

It's actually very simple, and is carried out in several stages:

If desired, the body can be strengthened. What will it give us? More precise and even bass, since the body panels will vibrate less and, accordingly, will introduce less overtones into the bass component of the sound. How to do it? This is purely everyone's business, because as many people as there are so many decisions. In general, everything consists in installing spacers, installing additional corners at the joints of the acoustic system walls, installing stiffeners on the speaker walls. Personally, I limited myself to pasting additional corners at the joints. You can also glue all the joints tightly. Unfortunately, I can’t show a photo, since the entire acoustic system is already dampened with foam rubber.
Sealing all joints and seams. It is carried out very simply with the help of various materials. For example, I used plumbing sealant. The procedure is simple: we cover the joints with sealant and gently smear it with your finger, thereby tightly sealing possible gaps.
In a hardware store we buy foam rubber 10 mm thick (I personally chose this thickness, do not take too much as you will strangle the case) and glue it to all walls except the front one with glue. Thus, we dampen the body, thereby increasing its virtual volume.

To do this, we buy terminal blocks with gold-plated connectors of a universal type in the store. Since the S-90 terminal block itself is large, and the new ones are small, we dismantle the connectors from the terminal blocks and install them on the body from the S-90 terminal block. After that, we lubricate the installation place with sealant (do not be sorry, then wipe off the excess) and put it all in place, tighten the screws. Here is a photo of what you should have:

5. We proceed to the alteration and installation of the filter in place:

First of all, carefully examine the filter, pay attention to the fasteners of parts, since inductors were often fastened with metal screws, which immediately knocks down the filter setting.
If there were problems in fasteners, bring it to the end by excluding metal parts from fasteners. There are also cases of assembling the filter on a metal plate, then transfer the filter to a plywood panel.
We take a leaf, a pen in our hands and carefully redraw all the elements of the circuit, restoring the filter circuit itself, so to speak, because the parameters of the speakers varied and for this reason they could change the filter circuit at the factory. By the way, we exclude the attenuator from the circuit, it just spoils the sound.
Now we pick up a soldering iron (preferably 100 watts) and disassemble the filter, or rather, simply remove all the jumpers that were installed from the factory.
Now we are assembling the filter, instead of jumpers we will now use an oxygen-free copper cable with a cross section of 4 mm 2, the cable can be bought at any car audio store. It should also be noted that you should not take a very expensive cable, as changes in sound quality will be insignificant, but the costs are simply enormous.
After assembling the filter, we solder the wires that will go to the speakers based on: for the LF link 4 mm 2, for the MF link 2.5 mm 2, for the HF link 2 mm 2.
We put the filter in place, after which we solder the terminal blocks to it (observe the polarity, otherwise you will lose the sound picture).
The very last step is to run the wires to the speakers, fix them and cover the filter with foam rubber.

You will get something similar to these photos:

6. Attenuator setting:

We remove all resistance from it.
We put it in its place.
We seal carefully.
Additionally, we close it with foam rubber (I closed it only on the front wall)
We install all the decorative panels to the end.

7. Installation of a phase inverter:

Everything is simple here, we put it back on the sealant, we carefully monitor that it is not pinched anywhere with foam rubber, as this will knock down its setting.

8. Install the overlay on the phase inverter:

We put it in the same way as it was removed, just put it on the sealant and on new screws, since the panel itself often rattles on the bass. Seal well the joint between the panel and the phase inverter.

9. Let's start installing the dynamic heads in place:

A) Install the HF head:

1) We remove that parody of the sealant that stands on it (some kind of felting gum, felting cardboard, is behind it).
2) We cut out a new seal, a mouse pad is perfect, in particular a black porous base.
3) Solder the wires to the speaker and install it in place.
4) We put in place a decorative overlay (grille if desired) and tighten it tightly with screws.

B) Install the midrange head:

1) We make a cylinder from foam rubber, of such a size that our box fits into it. We put this cylinder inside the column and pass a cable through it, which we bring out.

2) We pass the wire through the box (most likely you will have to expand the hole), after which we put the box in place, adjust the length of the wire and seal the hole into which the wire is passed.
3) Solder the wires to the speaker.
4) Now the crucial stage is the damping of the mid-frequency head. To do this, we sew a cylinder of foam rubber, of such a size that it fits tightly on the speaker frame and closes all the windows.

5) We fill the box with cotton wool, after fluffing it up.
6) We put the dynamic head, grille (optional) and frame in place and twist.

1) First, put back the bags with cotton wool that were removed during the disassembly of the columns. Solder the wires to the head. I tied the wires that are soldered to the head to the frame so that they do not hit the diffuser, because there is a possibility that when you put the speaker in place, the wires will bend and fall into the diffuser holder window.

2) We make a gasket from a porous material, for example
apply window sealant and carefully place the speaker in place.
3) Tighten the fixing screws. Do not apply great efforts, then the speaker will be spring loaded with a gasket and this will reduce the energy of vibrations transmitted to the case.
4) We put in place the grate (optional) and the decorative trim. If you nevertheless put a grate, then I advise you to cut out small triangles from the foam rubber and put it on the speaker at the place of its attachment, this will eliminate the vibration of the grate, and therefore remove overtones at high volume.

I came up with this solution a long time ago, look at the photos in more detail:

Conclusion:

After the revision, all the listeners (there were not many of them, five people, but I asked for the most honest information from them) noted more gentle and soft basses, a much cleaner middle, the tops remained practically unchanged (it seemed to me that they became a little cleaner). Also, the acoustics began to quietly take more high volumes.

In conclusion, I would like to say that the proposed method is the cheapest, simplest and most accessible. All components, of course, can still be repeatedly modified or changed. For example, instead of foam rubber, you can use felt (natural), which in theory will give top scores than foam rubber, it is also a good idea to use vibromastics. Many advise replacing 15GD-11A with a 5GDSH broadband, for me this is a bad idea, but this is everyone's business. 10GD-35 - it is advised to treat with a notch filter, 15GD-11A to be modified on the basis of halves from a tennis ball (by the way, the idea is quite interesting, I didn’t do it myself because I don’t have such speakers in stock).