Detailed speaker repair. Speaker repair - a guide in pictures

How to repair the speaker yourself? FAQ Part1

This is the first part of the loudspeaker head repair guide.

Here you will find information about the terminology used, speaker failures and the simplest repair, when only the replacement of the pigtails is required. Other issues will be discussed in future articles.

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How is the dynamic head arranged?

The diagram shows a cross section of a speaker. This is how low-frequency and mid-frequency loudspeaker heads are arranged.

1. Suspension (corrugation).
2. Flexible output (pigtail).
3. Bracket (attaches the pigtail to the diffuser).
4. Damper (protects the pigtail from breaking near the terminal).
5. Hole in housing for flexible output.
6. Insulating strip (holds the terminal).
7. Terminal.
8. Solders connecting the flexible lead to the terminal and the coil lead.
9. Coil output.
10. Coil.
11. Speaker housing (basket, frame).
12. Diffuser (membrane, diaphragm).
13. Dustproof cap (plug).
14. Centering washer.
15. Sleeve.
16. Pole tip.
17. Kern.
18. Top flange.
19. Magnet.
20. bottom flange.

The letters N and S denote the North and South poles of the magnet. This is the usual arrangement of the poles, although the opposite is occasionally found.

In the next picture, a conditional drawing of the tweeter in the context.

1. Coil output.
2. Insulating pad.
3. Suspension (elastic continuation of the dome).
4. Dome design diffuser (membrane, diaphragm).

The main difference between tweeters and midrange and woofers is the lack of a centering washer.

In addition, many tweeters use a domed cone, often referred to as a diaphragm. The dome and suspension of such speakers are a single unit, and the sleeve is attached to the dome.

Since the stroke of the tweeter cone is small, the coil leads often play the role of flexible leads.

What are speaker failures?

Speaker failures are caused by misuse, improper assembly, or normal wear and tear.

Incorrect operation.

Most often, damage occurs due to excess power supplied to the speaker. One of the reasons for such errors may be confusion with the method of determining the power of the speaker and amplifier. This is due to the fact that the same numerical values ​​​​of effective, root mean square (RMS), or as it is also called, sinusoidal power and amplitude or musical power create a current in the speaker coil that differs by two times.

Another reason for overloading the speakers is the careless redistribution of power between the heads of multi-band speakers. Most often, tweeters suffer from this - tweeters. The fact is that the power of tweeters in multi-band systems can be less than 10% of the total speaker power. And if the user, using an equalizer, supplies most of the power of the amplifier to the tweeter, then the death of the latter can be instantaneous.

They also take place mechanical damage dust cap, hanger and diffuser. Sometimes these damages lead to misalignment, which in turn leads to the destruction of the coil and sleeve.

The destruction of the sleeve and the coil can also be caused by the displacement of the core. In such cases, the sleeve together with the coil is wedged in the magnetic gap. This usually occurs as a result of a loudspeaker or speaker being dropped.

Unqualified assembly.

Due to improper assembly, the sleeve, coil, hanger or centering washer may come off. Poor gluing can also cause extraneous overtones.

Incorrect fastening of flexible leads can significantly reduce their life.

Normal wear.

If the loudspeaker head is assembled with high quality, then as a result of normal wear, the suspension and pigtails suffer the most. The diffuser can also collapse if its margin of safety does not match the power of the speaker.

How to identify a faulty speaker element without disassembly?

All speaker malfunctions can be divided into “mechanical” and “electrical” ones. However, it is very difficult to distinguish some electrical defects from mechanical ones by ear.

If none external changes, such as the destruction of the corrugation or diffuser was not detected, but at the same time, extraneous overtones appeared in the form of crackling or there was a periodic loss of sound, then the flexible conclusions should first be checked.

To do this, connect a pointer ohmmeter to the speaker terminals and move the pigtails with the diffuser stationary. If at the same time the ohmmeter needle moves, then the flexible output is damaged.

Other electrical defects include broken coils and short circuits in part of the coil turns or the entire coil. These defects can also be detected with an ohmmeter.

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To do this, a master oscillator signal is fed to the input of the amplifier.

A partially unstuck coil or part of the turns can be detected by smoothly changing the frequency of the generator or turning the generator into the GKCh mode (Sweeping Frequency Generator).

When checking this speaker, the GKCh range of 20Hz ... 2kHz with a period of 3 seconds was used. In this speaker, apparently, a significant part of the coil has come unstuck, since overtones are heard in a wide frequency range. If a small fragment of the coil is peeled off from the sleeve, overtones can appear only at some particular frequency, and only when the damaged structural element enters resonance.

In some cases, to identify a malfunction, it is useful to use an infrared generator. low frequencies. This can help to identify, for example, defects in the bonding of a rubber corrugation with a diffuser. The arrow shows the place where the overtone is formed.

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The rubbing of the sleeve on the core or coil on the inner surface of the upper flange can also be twisted at a frequency of several hertz, if you lightly press the corrugation waves with your fingers.

More serious damage to the speakers is even easier to identify.

So, for example, if something is heard when the speaker is turned over, it means that part of the turns or the entire coil has fallen off the sleeve.

If the diffuser moves very poorly, then most likely the coil has fallen off and stuck the sleeve in the magnetic gap.

If the diffuser does not move at all, then the core may have moved and jammed the coil along with the sleeve.

Never try to disassemble such a speaker without first releasing the sleeve, as this may also damage the cone.

How to replace speaker pigtails?

Be extremely careful when replacing pigtails on an unassembled speaker, as a steel tool attracted by the magnetic system can damage the cone and dust cap.

If access to the flexible outputs (pigtails) of the speaker is free, then you can try to replace them without disassembling the speaker. But, in some cases, the speaker will still have to be disassembled. The picture shows a broken flexible output.

Dismantling the old flexible leads should be done with the utmost care so as not to damage the diffuser or break the coil leads.

First, the brass bracket is unbent, holding the flexible output, if, of course, there is one.

Then the place of soldering is heated with a soldering iron in order to separate from the diffuser, both the flexible output and the output of the coil. Usually, after warming up, the glue softens and the leads can be dismantled.

What can replace damaged flexible leads?

Of course, the easiest solution is to borrow the pigtails from another speaker of similar power, or order from a supplier that sells speaker parts. But, if this is not possible, or you want to save on spare parts, then you can make surrogate pigtails yourself.

The first and simpler option is to replace a failed pigtail with a piece of MGTF wire of a suitable section. Who first came up with this, I don’t know, but it was with such flexible leads that the once popular 4A32 speakers went on sale.

Another option is to make pigtails from Soviet-made flexible telephone cable. It can still be found among all the rubbish at flea markets.

I am familiar with two types of such cable. In one, each wire consists of seven strands, and in the other of fourteen. Each core is made by winding a copper tape on a lavsan thread. In the section, the tape has the shape of a rectangle with dimensions of 0.03 x 0.3 mm.

0,03 * 0,3 * 14 = 0,126 (mm²)

As you can see, the cross section is small, so for powerful speakers, you can twist two or more stranded wires.

First, a piece or pieces of telephone cable are prepared with a soldering iron.

The insulation is removed in small sections to avoid damage to the cores.

Then the cores of each stranded wire are untwisted and twisted again into one wire.

And finally, the flexible lead is carefully glued twice with rubber or 88th glue with an interval of 20 minutes.

Before the first gluing, the twist must be free so that the glue penetrates between the cores. Immediately after the first gluing, the cores are twisted to the end. The second sizing finally fixes the cores relative to each other.

Thus, it is possible to make a flexible output for a speaker of any power.

If there is no telephone or MGTF wire, then as a temporary measure, you can use the MGSHV wire or even a braid from a shielded wire, but such pigtails do not last long, and the load on the diffuser is greater due to less flexibility.

When installing a flexible output, it must be taken into account that the weakest points of this node are the places where the pigtail is attached to the diffuser and the terminal.

If the fastening brackets are damaged or lost, then the pigtail is fastened with two crossed stitches of thread. Then the attachment point is glued with glue with a large dry residue. Suitable weathered BF-2 / BF-4.

To prevent premature fracture of the pigtail, the attachment points are covered with several layers of rubber or 88th glue with the transition to a flexible lead.

Even the highest quality speakers are not immune to breakage. They can be caused by a variety of reasons. If the speaker suddenly stopped producing sound, and during the diagnostics of the speaker system it became clear that the reason for this was some kind of internal breakdown of the speaker, it is not at all necessary to contact service center and even more so to go buy new equipment.

Nowadays, repairing a column is very simple - all spare parts are available for sale, it remains only to find the necessary tools and carefully study the technology of column repair. To make sure everything works out, you can watch the corresponding video and simply follow the proposed instructions step by step.

If you have difficulty disassembling the speakers, you can read.

Types of speaker malfunctions

The main part of any speaker is a dynamic radiator, which converts an electrical signal into sound waves. It also breaks down most of the time. What are the most common speaker problems?

All breakdowns of emitters are usually associated with three main reasons:

• incorrect operation;
• factory marriage - the use of low-quality parts or errors when assembling the device;
• natural wear and tear of acoustic equipment.

It is very simple to attribute the breakdown to one of the reasons - in the event of a marriage during production, the speakers, as a rule, break down within a short time after purchase, while natural wear and tear, on the contrary, takes a very long time - with correct use even cheap quality speakers can last at least a decade. Thus, a sudden breakdown most often refers to errors when working with speakers.

Misuse

The main cause of breakdowns during the operation of speakers is non-compliance with the permissible power limit of the signal supplied to the emitter. Most often this is due to the fact that the user is mistaken in determining the power of the speaker and amplifier. This is quite simple to do, since power can be calculated in several ways. The values ​​of effective, sinusoidal and amplitude powers can be strikingly different from each other - the excess when taking into account the wrong type of power can exceed 200%. Of course, the column burns out the first time you turn it on.

Overloading of dynamic radiators is very common in acoustic systems whose speakers are equipped with multiple speakers. In such a speaker, the power of the electrical signal may not be properly distributed between the tweeter, mid-range speaker and subwoofer. As a rule, the victim of such a problem is twitter, which requires significantly less power than its counterparts. The power of the tweeter is usually no more than 1/10 of the total power of the speaker. If the user tries to apply more current to the tweeter by boosting the ultra-high frequencies too much with the EQ, the fragile high-frequency driver can break instantly.

In addition to electrical problems, mechanical damage to any element of the speaker can also occur. Usually it is protected by a fabric or metal decorative grille, but damage to the emitter, however, is quite simple. The cap that protects the device from dust, the diffuser suspension and the membrane itself can be damaged - a thin film, often paper, which is extremely easy to tear or pierce. The consequences of these damages can be very serious: alignment is disturbed, due to which the coil or sleeve breaks - sound reproduction becomes physically impossible. The displacement of the core from the center of the speaker leads to the same result - in this case, the most important parts of the device get stuck in a magnetic trap.

As a rule, very careless handling of the speakers leads to such breakdowns - most often, the device falls. In this case, they can be damaged as fragile portable speakers from not the most durable materials, and massive floorstanding speakers with high power. Although the latter, of course, are better protected from mechanical damage.

Manufacturing defects

All parts of the column are usually glued together, and improper gluing can cause fixed parts to move out of their places. Even the diffuser can peel off, as a result of which its vibration and, accordingly, the receipt of sound waves will be impossible. Poor fastening of moving parts and wires significantly reduces the resource of the speaker, and natural wear occurs too quickly.

natural wear and tear

The most fragile parts of the device - the suspension and flexible leads - that is, the diffuser holder and the wire leading the signal to the coil, suffer the most from wear when properly assembled.

Diagnostics

It seems that it is very easy to distinguish mechanical damage from electrical damage - just remove the protective panel and inspect the speaker for damage. If everything is in order with the integrity of the parts, then the breakdown is related to the electrical part. However, it is difficult to distinguish some types of breakdowns by ear and eye - for example, a malfunction of the flexible output of the coil. In this case, most often the sound does not disappear completely - the column can make extraneous sounds and from time to time fall silent.

To determine the breakdown of the flexible output, as well as coil malfunctions, an ohmmeter is used, connected to the speaker terminals with a static membrane. If the arrow starts to twitch, the problem is here. To fix the breakdown, you will have to disassemble the speaker, separate the broken parts and put in new ones - you can buy them at any radio engineering store.

With the help of a low-frequency generator and infrasound, it is possible to calculate the unstuck coil, part of its turns, as well as the diffuser that has moved away from the suspension. In this case, extraneous sounds will appear. They will be heard at a certain frequency when the damaged part of the speaker comes into resonance with the sound.

As for more serious breakdowns, they are calculated much easier - even special tools are not needed:

• gently shake the speaker - if something rolls inside, it means that the coil has fallen off the sleeve;
• take a closer look at the diffuser - if it moves reluctantly, then the effect of the coil on it has decreased - probably due to the displacement of the coil, the sleeve is stuck between the magnets;
• if the membrane does not move, it is possible that the coil is stuck with the sleeve due to the displacement of the core.

In the last two cases, the repair consists in releasing the sleeve, then disassembling the device and eliminating the cause of the problem. It is impossible to disassemble the speaker while the sleeve is between the magnets - this can also damage the diffuser membrane.

Replacement of pigtails

Repair can be carried out in two situations - with free access to the terminals, in which case disassembly of the speaker is not required, and with the device closed. In the first case, of course, the repair is much simpler. Due to the presence of magnets inside the speaker, it is advisable to use a tool that is not made of steel, if one is available, since magnetizing it can damage the membrane or cap.

The pigtail is bonded to the solenoid coil's own wiring. To separate these parts, you need to warm up the place of gluing with a soldering iron and carefully tear off the old pigtail from the coil. Care must be taken not to damage serviceable parts.

New lead is best purchased from speaker replacement parts suppliers. But you can make it with your own hands - for this, any stranded copper wire with the same section as the original part. Its twist must be made the same as that of the flexible output being replaced. All cores are glued together with special glue and tinned. Then the spare part must be glued to the coil output and securely fixed on the inner surface of the diffuser.

Speaker disassembly to replace parts

The complexity of disassembly depends only on the type of glue used in the manufacture of the emitter. If the structure was fastened with epoxy, disassembling the device can be very problematic. But if the applied glue dissolves with acetone or alcohol, you can safely proceed to repair work. It is advisable to use acetone, even if the glue dissolves better with ethyl acetate - its toxicity is much lower, so the work will be safer for health.

Disassembly goes in the following order:

• The hanger is peeling off. This must be done carefully so as not to damage it. Under the suspension, acetone is carefully poured with a pipette. When the glue begins to dissolve, a match or toothpick is inserted into the unstuck place as a backup. Moving around the entire circumference, in the same way we peel off the entire suspension.
• The centering washer is peeled off. This can be done either from the body side or from the diffuser side.

After removing these two parts will open full access to the interior of the speaker. Then it will be possible to repair any of its parts: it is best to remove and replace them, although you can try and replace, for example, winding the coil with your own hands. However, without the experience of such work, the result is unlikely to be satisfactory.

Speaker repair: video

Have the speakers of your favorite acoustics begun to wheeze? Do not rush to write them off, with such symptoms it is very easy to repair the speakers yourself. Usually the speaker begins to wheeze due to the numerous dust that has accumulated over the years of trouble-free operation between the core and the coil, which, when the speaker cone vibrates, generates an unpleasant sound in the form of speaker snoring. In this case, the repair of the speakers must begin with disassembly and removal of dust or small debris that causes a wheezing sound.

The device and design of the speakers

To repair speakers, it is important to understand how a typical representative from the world of audio technology works, let's analyze its device and design, for this we turn to the figure below.

The speaker consists of a magnetic system located on the back side. It consists of a ring magnet made of special ferromagnetic alloys or magnetic ceramics, steel flanges and a cylinder (Core). Between the core and the flange there is a gap in which a magnetic field is generated. In the gap, there is an inductor wound with a thin copper wire on a rigid cylindrical frame. It is also sometimes called a voice coil. The frame of the coil is fastened to a diffuser - it then “moves” the air, creating compression and rarefaction - acoustic waves.

The diffuser can be made from various materials, but is usually made from compressed paper pulp. To prevent the coil from touching the walls of the core, it must be placed in the middle of the magnetic gap using a centering washer. The diffuser is mounted on a metal frame. Its edges are corrugated, for the ability to make free vibrations.

Thin wires from the coil go to the outer side of the diffuser and are fastened with special rivets, and a stranded copper wire is attached to them on the other side. Then these stranded conductors go to the petals, so the speaker is connected to the circuit.

Now you can start repairing the speakers with your own hands.

Speaker designation on the diagram

If an alternating current is passed through the voice coil electricity, then will arise, which will interact with the constant magnetic field of the speaker system. This causes the coil to either be drawn into the gap or pushed out of it, depending on the direction of the currents. The mechanical vibrations of the coil are transmitted to the diffuser, which oscillates in time depending on the frequency of the alternating current, generating acoustic vibrations.

The speaker on the diagrams is indicated as follows. Next to the designation there are letters B or BA and the serial number of the speaker in the diagram.

On the example of the Focal Polyglass 165 VRS model, because these speakers have high quality sound and, accordingly, are very expensive, I decided to try to repair them. On both speakers visual inspection I noticed a break in the wires, and it was impossible to solder without disassembly.

The cone in this speaker was woven from cloth. Rubber suspension. It took about an hour to disassemble the head. A solvent was used to separate the suspension. the main problem consisted in the fact that the main frame of the head was made of plastic, which was "dissolved" by the solvent.

The centering washer was separated with a mounting knife, access to the coil appeared. It is usually wound onto a metal sleeve to a very high accuracy tolerance. The sleeve itself is interesting with holes for cooling. The cap is made of plastic. It remains only to solder new flexible wires to the coil.

The assembly process must be carried out in the reverse order, what was peeled off with such difficulty must be glued back, I used super glue for this, as it dries quickly. If you use long-drying glue, you will have to clamp it under pressure and make special patterns. An hour later, the speakers turned on, the sound was just magical.

Speaker repair was successful

I doubt that this miracle device is of great practical value, but anyone can assemble just for fun in about thirty minutes. Although you may have had an unsuccessful repair and something is better than nothing.

The simplest electrostatic speaker is arranged as follows: the film is located parallel to a flat metal plate with holes for the free passage of air. Gap ( d) between the surface and the film, they try to make as little as possible, but at the same time nothing should interfere with the vibrations of the film.

If a certain voltage U n with a nominal value of about hundreds of volts (polarizing) is applied between the plate and the film with oscillations of the audio frequency U superimposed on it, then an electric field is formed in the air gap, causing some attraction of the plate and film, thereby creating sound.

Do-it-yourself electrostatic speaker design. The dimensions of the plates are 160 by 180 mm, each has many holes with a diameter of 2 mm. The plates must be slightly concave on the foil side, otherwise spacers will be required.

The design of the loudspeaker radiator is shown in the figure above. Plates 1 are arranged with foil to each other, between them there is a sheet of plastic film 2 (with metallization on the right), and the whole system is linked by screws 3 at the corners with a thickness of about 35 microns. Under the screws, you need to find insulating washers, and from the foil of the plates you need to draw conclusions 4, for the speaker terminals, or you need to make protrusions on the plates and the wires are soldered directly to the foil on the protrusions.

If the plates used do not have a natural concavity, a thin cardboard pad 5 should be installed around the perimeter on the side of the film where there is no metallization.

To reduce the effect of "acoustic short circuit", it is desirable to install the loudspeaker in any case, for this the polished side wall of the case of a very old kinescope TV is perfect.

For home-made tests, a self-assembled

The best acoustic results can be obtained with a differential design of electrostatic loudspeakers, in which the film does not experience a constant force of attraction, due to the polarizing voltage, and oscillates much more easily, encountering only some air resistance. However, two anti-phase audio voltages of the same amplitude are required here, obtained from a transformer with a symmetrical secondary winding. You will also need a two-layer film with a metallization in the middle.

A little theory for speaker repair

The theory behind our simplest speaker, the loudspeaker, is extremely simple: applied voltage U generates a field of tension E = U/d. per charge q force acting in this field F = qE. And the sound pressure created by the loudspeaker at the membrane itself: p = f/s, where S is the area of ​​the membrane. Divide by area and get p = qE/S. Value o = q/S is called the surface charge density (we assume that the charge is uniformly distributed over the surface of the film-membrane). Then p = aE. The surface charge density is directly related to the field strength: e0E \u003d a, where e0 \u003d 8.85 * 10-12 F / m- electrical constant. Finally, we have: p = e0E2. The expression on the right corresponds to twice the volumetric energy density of the electric field, and the sound pressure is proportional to it!

That is why one should try to increase the field strength (voltage between the film and the plate) and reduce the gap d between them. The limit is imposed by the electrical strength of the air - too much field strength causes a quiet or even corona discharge.

The sound pressure is proportional to the square of the field strength, and hence the applied voltage U. It does not depend on the polarity of U, which makes it necessary to use, in addition to sound, also a constant polarizing voltage. To reduce "quadratic" distortion U choose much more U.

As a consequence of the speaker device, it is, in its direct essence, a typical converter that converts an electrical signal into sound waves. But in accordance with Faraday's law, with a light tap on the cone, a sinusoidal signal is formed on its contact. The position of the first half-cycle of the generated signal determines the polarity of the device. Thus, in accordance with the diagram below, the position (positive and negative) of the half-cycle of the signal from the speaker is recognized.

Device polarity is defined as follows:

If the first half cycle of the sine wave is positive: it is amplified by the op amp from the loudspeaker (IC1:C). Then this amplified signal follows the input of the logic element (IC2:C), and its second input is connected to the output 2 of the flip-flop IC3:A. When the amplified signal is in a logic state, the output of the logic element is also one, which switches the flip-flop IC3:B, and LED1 blinks once.
When the first half of the sine wave is negative, LED2 will blink once.

Music in the car is a pleasure and entertainment on the road, but there is one unpleasant moment. The speakers in the car are constantly exposed to dust and dirt, all sorts of debris flies in from the street, especially the speakers in the rear shelf of hatchbacks suffer from this. Over time, debris accumulates in them so much that the diffuser begins to emit a terrible rattle during operation.

There are a couple of car, three-way, coaxial speakers measuring 6x9 "with the above symptoms. I must say right away that when working, you need to apply maximum caution, accuracy and patience, if this is not about you, then it's better not to even start.

In the preface, I would like to recall a little theory about the design and operation of dynamic heads, so it will be easier for me to further explain the process in the text.

The basis of a dynamic head (dynamics) is a basket, a frame on which everything rests. A diffuser is glued into the wide part of the basket through a suspension. The diffuser just makes a sound when it vibrates, and the suspension ensures its freedom of movement. The diffuser is usually dome shaped and can be made of pressed paper, polypropylene or even aluminum. The suspension is usually made of rubber, in low-power woofers and midrange speakers made of paper. At the narrowing of the diffuser there is a coil that moves on a core (core) around the magnet. The permanent magnet increases the EMF of the electromagnetic field, thereby increasing the course of movement of the diffuser. The coil on the core is centered by a washer creating the necessary uniform gap between the coil. The centering washer is also glued to the speaker basket. Without it, the coil would touch the magnet or core. From the coil, the wires are led to the diffuser and from it, through the flexible "antennae" to the contact pad for connection to the audio equipment.

The crunch and noise in the operation of the speaker occurs due to debris that has fallen between the coil and the core during their operation (movement). Such debris may contain metal particles and other magnetic dust, which is problematic to remove. in a simple way. In this case speaker repair starts with disassembly. I want to make a reservation right away that the speakers, by their design, are not intended for disassembly and, accordingly, the manufacturers of these speakers do not provide for this in their design. But everything that has been assembled can be disassembled, you just need to properly attach your head and hands.

Speaker disassembly begins with soldering the current-carrying conductors from the diffuser to the terminal block. In our case, this is a car multi-band speaker on the core of which two more smaller ones are attached - midrange and tweeters. From them, the conductors also need to be unsoldered, and the body that fastens them to the core must be unscrewed with a screw passing through the core from the side of the magnet. In the usual dynamics, there is a dust cap in this place of the diffuser and it is not necessary to remove it.

The next step in speaker repair there will be a separation of the diffuser from the basket. We will separate the diffuser together with the suspension, coil and centering washer. In factories and factories, glue is usually used in the likeness of a domestic "moment", so I dissolve it with acetone. We collect acetone in a regular medical syringe and moisten the suspension in places where it is glued to the basket. Well, if you can bend the suspension a little and process it under it, closer to the glue. We do the same with the centering washer, but do not pour a lot of acetone, you can peel off something you need.

A lot of time can pass before acetone takes effect, and it is necessary to periodically re-wet with acetone, because it quickly disappears. When separating the diffuser, you do not need to pull it, you can tear or deform the suspension and the diffuser itself, you can help with a flat screwdriver using it as a spatula. It is necessary to act carefully, slowly, especially when working with sharp objects, otherwise you can easily damage the diffuser and all the work for nothing, and the speaker for the trash. If it does not peel off, it is better to add acetone and wait. After separating the diffuser, we move on to the centering washer, it must be handled with the same care and do the same.

Having separated the diffuser from the basket, you can proceed to cleaning the hole around the core (core). To be honest, there are no special recipes here and it is not easy to clean a magnet from metal debris. The gap is very narrow and crawling there with any brushes is not realistic. I managed to clean it off with a metal clip (photo below), which magnetized itself and metal debris stuck to it. You can try with a wooden or plastic stick, sometimes you can blow it with air under high pressure. In general, we clean as it turns out, the main thing is that there would be no debris left around the core. It is also necessary to clean the coil itself, a lot of debris also sticks to it. It must be handled with no less care than with other parts, you can damage its round shape and then you have to look for a suitable round mandrels and straighten it, otherwise the noise from the speaker will be even more than before. By the way, the photo below shows how the aluminum frame of the coil is eaten away by debris during operation, it happens that the wire frays and a break occurs, in this case a new coil is wound, which will require even more time, concentration and action.

Upon completion of the cleaning, we can say that we have mastered this speaker repair, but it remains to be assembled, and here, too, there are some nuances.

The assembly is carried out in the reverse order by gluing the elements into place, but you must not just glue it, but glue it evenly! To do this, you need to find an old, unnecessary x-ray or a piece of film, and cut it to size so that it is folded into a tube and placed in the gap between the coil and the core (core). This film will help us center the coil and set an even gap. It is desirable to take the thickness of the film such that it fits snugly into the gap without backlash. We put the diffuser in the basket and center the coil with a film, align and position exactly on the basket. First of all, we glue the centering washer, we will glue it with the usual “moment” glue. We smear the gluing area and press it, in fact we do it as it is written in the instructions for the glue. Pressing is inconvenient, so ordinary clothespins will help us. Be sure to wait for the glue to set, otherwise our centering may go astray. As soon as the glue grabs the washer, we glue the diffuser to the basket, but do not remove the film, let it remain until the glue dries completely. After gluing the diffuser, you can put the rim around the suspension in place, turn the speaker over, put it on a flat surface and press it with something heavy. When the glue is completely dry, we check the movement of the diffuser by gently pressing it with your fingers, no extraneous sounds should not be, the diffuser should go in and out easily and without jamming. If yes, then we did everything correctly and centered well, if not, we will have to repeat everything.

Upon completion of work with glue and upon successful completion of the task of removing debris from the bowels of the speaker, it remains to put the midrange speakers in place on the cores and solder all the wires in place.

P.S. The metal mesh cover, which usually comes with the speaker, practically does not protect it from dust and small debris, in the future, in order for the speaker to live longer without repair, I can advise you to paste ordinary women's nylon tights inside this protective mesh in two or three layers. Through this filter small trash will not get inside, will remain appearance and the speaker itself, and the sound will pass without problems.

This concludes the article. speaker repair and I hope that the information will be useful to you.

Recently, a dynamic head was brought in for repair, which had a worn out suspension. I decided to share a simple speaker repair technology with you, dear radio amateurs. So, everything is very simple, but for repairs we need to have transparent adhesive tape and moment glue (rubber, waterproof) on hand, if such glue is not available, you can get by with universal waterproof glue. We take adhesive tape and glue the holes and dangling places of suspension with it.

After everything is already pasted over, make sure that there are no small holes left (so that there is no leakage of the poured glue). To give a round shape, the adhesive tape should be warmed up a little (you can use a lighter).

Next, we begin the restoration of the speaker suspension. We take the glue for a moment and spread it on the adhesive tape, try to do it as neatly and smoothly as possible. Make sure the glue sits evenly. Then you need to leave the head to dry.

Glue dries within 5-7 hours, and then turns into rubber. While the glue is drying, the head must be placed on a flat surface in order for the glue to dry evenly over the entire suspension parameter.

After a few hours, the dynamic head is ready for use. There is almost no difference between the factory and home-made suspension, the sound is clear and high-quality, by the way, the client really liked it, I hope you will like it too.

In general, for many years, almost the same technology was used to replace the suspension of dynamic heads by the S-30 radio technician. These heads are quite quality sound, they feel great at low frequencies (although the midrange is lame), in a word, a good head for a powerful subwoofer, but there is one drawback - the foam rubber suspension. On deep bass at full volume, it will last no more than 20 minutes. I used dozens of ways to replace the suspension of such a head, but not one of them suited me - it wheezes, then the speaker becomes very hard, then the alignment is disturbed and the varnish is peeled off the coil, but then I just decided to make a home-made suspension for such a head using adhesive tape and glue moment. The result was amazing! The head became the basis for a powerful car subwoofer and has been used in a friend's car for 3 years. The amplifier is powerful, assembled on the basis of the famous TDA7294 whose peak power can reach up to 110 watts! And imagine - the head can easily withstand this power, and the suspension does not break.

And here is another secret of a homemade suspension - do not spare the glue! The more you need to fill it, the better, and if there are dynamic heads with a worn out suspension at home (such a defect is very common), then do not rush to throw them away, they will still serve you faithfully for several years! It is advisable to use super glue to pre-fix the adhesive tape. The speaker parameters will not be affected by such a rework, and the response to low frequencies will even be better than when the speaker was released from the factory - AKA.

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