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Dynamic head repair (dynamics) - laborious process, especially if it is associated with the need to rewind the coil of the electromagnetic system, since this operation requires almost complete disassembly speaker with extraction of its cone. It is advisable to carry out such a complex repair at a fairly high price for a new dynamic head, the availability of necessary tools and materials, as well as basic knowledge in the field of electronics.

The article considers a relatively simple case of restoring the speaker coil: without the need to manufacture a new base for the coil (the aluminum base is well preserved); due to the considerable power of the speaker, an enamel wire of an impressive cross section is used, which is easy to lay.

To rewind the speaker coil, we need the following basic tools and tools:

1. Cylindrical, all-metal mandrel (blank), for installation inside the coil frame during winding.
2. Glue "BF-2". Glue "Moment". Acetone. Ethanol.
3. Enamelled wire (enamel wire) of a certain length and section, for the manufacture of a new coil winding.
4. Winding machine.
5. Calipers.
6. Electric soldering iron.

100 ml bottle with BF-2 glue.
No more than 10 ml is consumed per coil rewind.

Aluminum (solid) mandrel.
The outside diameter is 49.5 +/-0.05mm. The diameter of the inner hole is 8 mm. Length - about 60 mm.

Coil IEK KU 09-18 (24V) as a source of winding wire.
Before winding, the wire must be thoroughly straightened and rewound onto another storage coil, which has a round shape.

Speaker disassembly.

Most of the dynamic heads are not intended for their disassembly and are, as it were, disposable (non-separable, of little use for repair) components of acoustic systems. In practice, successfully disassemble the speaker standard design and it is often possible to assemble it again. The main task is to soften the glue with which the set is held together. constituent parts dynamics, and separating them from each other without injury and deformation.

Speaker fixing screws are hex slot(photo on the left).
Subwoofer without speaker (photo on the right).

Subwoofer speaker (before repair).

There is a "10P32" marking on the speaker, probably indicatingdiameter 10 inches andresistance 3.2 Ohm.

The sequence of operations is as follows.

First, we solder the flexible braided conductors (current leads) from the socket on the speaker basket.

Secondly, remove the dust cap. To do this, we impregnate the adhesive seam with acetone (for example, with a syringe with a needle), separate the cap from the diffuser with the tip of a knife. Based on the results of this operation, a conclusion should be drawn about the quality of the softening of the adhesive with acetone, and the need to use some other solvent.

Removing the dust cap.

Thirdly, we disconnect the upper suspension of the diffuser from the basket, soaking the adhesive seam with a solvent. In the case of repairing a subwoofer speaker that has a durable rubber suspension, the task is greatly simplified.

Fourthly, we very carefully separate the centering washer of the lower diffuser suspension from the speaker basket. To do this, we abundantly impregnate the adhesive seam with a solvent, wait a few minutes, and slowly, using a small flat screwdriver, separate the washer from the basket.

The diffuser should now be free to pull out of the basket. It is not necessary to remove the centering washer from the diffuser.

The diffuser is marked "YC-246A".

We evaluate the state of the electromagnetic system of the speaker: coils, permanent magnet. In our case, the native coil of the SVEN speaker, wound with copper enamel wire round section, had a deplorable appearance: enamel blackened from excessive heating, several extreme turns peeled off, the coil is easily unwound (the glue is completely burned out). Most likely, this was the result of a failure. The conclusion is obvious - it is necessary complete replacement coil wires.

Condition of the old voice coil. The aluminum frame was not damaged.

The choice of wire for winding.

An easy way to determine with sufficient accuracy the required length of a new wire is to calculate the length of one turn (knowing its radius), multiply by the number of turns in the layer and by the number of layers. The SVEN subwoofer speaker has a four-layer coil with 34 turns in each layer. According to measurements, the outer diameter of the burnt coil is 53 mm, therefore, the length of one turn (at the maximum, on the surface of the coil) is: 53 x 3.14 = 166.42 mm. We multiply this length by the total number of turns in the coil: 166.42 x 34 x 4 = 22633.12 mm. Thus, rounding up (adding a small margin), we need at least 23 meters of enameled wire to rewind the coil.

The outer and inner diameters of the burnt coil are 53 and 50 mm, respectively (measurements are approximate due to the presence of winding deformations).

The wire diameter is determined using a micrometer or caliper. The circular area is calculated by the well-known formula: S = Pi x R 2, where R is the radius of the wire. It is necessary to measure the diameter of the wire both by copper (with the varnish insulation removed) and by insulation (the outer diameter of the future coil is also important for us). To remove the insulating varnish from the wire, when measuring the diameter on copper, it is necessary to heat the tip of the wire to red (burn the varnish) and remove the combustion products with a solvent. According to the results of measurements, the burnt coil of the subwoofer speaker was wound with a wire with a diameter of 0.38 mm for copper (section 0.113 sq. mm) and 0.44 mm for varnish. Now a very difficult task lies ahead - to find the same, or very close, wire. If you can’t buy the right wire, you can wind it from any electronic device. For example, as enamel wire donors, coils have proven themselves well. Depending on the voltage and type of contactor, wire is used in their coils. different sections and lengths.

The wire diameter of the burnt coil.
For copper - 0.38 mm (photo on the left); on varnish - 0.44 mm (photo on the right).

Wire diameter for new winding.
For copper - 0.35 mm (photo on the left); on varnish - 0.40 mm (photo on the right).

If, as a result of a long search, it was not possible to find the original wire, then you can use a wire of a different section, recalculating the number of turns, layers and coil resistance. It must be remembered that by changing the cross section of the wire, the characteristics of the dynamic head change, as well as the magnetic gap and the winding height. Before deciding on the use of "foreign" wire in the winding of the coil, it is necessary to accurately calculate the geometric and electrical parameters future coil, predict the operation of the dynamic head with new parameters in the speaker system.

To rewind the speaker coil from the SVEN subwoofer, we managed to find a wire with similar parameters (0.35 mm in diameter for copper, 0.40 for varnish) in the coil KU 09-18 (24V) of the IEK contactor. The length of the wire in the coil of the contactor is almost twice the required value.

Winding data (wire diameter for copper and number of turns) in the coils of starters of the PME and PAE series for a current frequency of 50 Hz.

Winding machine manufacturing.

The machine is a U-shaped structure with an axis of rotation of the mandrel (blank) of the speaker coil and an axis of rotation of the coil with a supply of winding wire. For the axes, it is necessary to provide for the possibility of adjusting the rotational forces, that is, some kind of brake, to prevent self-reeling of the wire. Also, the design of the machine must have places for fastening the degreasing and glue rollers, through which the wire will pass before the speaker coil enters. If the repair of speakers is not a frequent occupation, then it is enough to make hastily shown in the figure below, a construction from scraps of an MDF board.

Often you can meet requests for help in repairing and rewinding the coils of burned out speakers, articles on this topic have long been on the Internet, but we decided to make our own. So, I got my hands on a burned-out Pioneer subwoofer speaker from a TS-WX303 subwoofer, the nominal power of the speaker is about 250 watts. It seems to me that former owner went too far with power, as a result of which our speaker burned out.

When the diffuser was pressed, a clearly audible rattle was emitted, this is the coil rubbing against the magnetic core, possibly falling apart, after disassembling the speaker everything will become clear. The main difficulty is just to disassemble the speaker, because it is very important not to damage the speaker suspension, it’s good when the suspensions are rubber, they peel off and tear off with a bang, in the case of foam rubber and their analogues, everything is not as simple as it might seem at first glance.

So, a photo of my patient:

Personally, I disassemble speakers in one of two ways, with a thin blade, or by soaking in solvent. In the second case, you need to work strictly on the street or in a well-ventilated area, but not at home and not in the entrance. In advance, you need to prepare all the tools necessary for repair, you can use primary tools for dismantling the suspension and centering washer. The centering washer is located under the diffuser, usually yellow color made of thick pressed mesh fabric.

For soaking, you can use a syringe, draw the solvent into the syringe and carefully spray the extreme parts of the suspension, in the place where it is glued to the "basket". It usually takes a long time to soak, in 5 minutes you will not separate the suspension from the speaker housing. The centering washer is soaked in exactly the same way.

This is not the first time I rewind the speakers, and the dismantling operation for this speaker took me about 5-7 minutes. After soaking, we solder the conductive wires from the terminals and remove the diffuser with the coil from the frame, in principle it is possible and necessary to solder the wires before soaking, it will be more convenient ... We look at the photo of the coil of my burnt speaker:

The photo clearly shows overheated and charred turns of copper wire, this coil will have to be unwound completely and rewound again. some unscrupulous repairmen practice next view repair: part of the burnt wire is unwound and the break points are connected together by soldering. Naturally, such a "homeless repair" will not last long, in addition, after unwinding part of the turns from the coil, it will significantly reduce the overall resistance of the speaker, which will certainly affect the power.

In general, if the coil is more or less alive, you can leave it, after soaking the coil with varnish, it will last - but not for long. This option is applicable for beginners, for those who are afraid to rewind the coil due to certain circumstances (for example, there is no necessary wire for rewinding).

The speaker coil should ideally be wound with BF-2 glue. Finding it is not easy, but it is the most the best option. We glue the hanger rubber glue 88, it is usually sold in small jars in construction stores, with such glue glue carpets on subwoofers:

Finding the right wire is also a problem, good wire donors are coils of contactors (starters), which are sold separately in electrical equipment stores, are not expensive, I use just such a wire. Also, the necessary wire can be found in the degaussing loop of kinescopes (CRT), a sample of my wire for winding is below in the photo:

I removed this wire and rewound just from the starter, the wire diameter is approximately 0.35, by the way, winding too thin wire not recommended speaker power drops sharply. If you take the wire thinner than it was, then you will have to make a little more turns than it was, otherwise the speaker resistance will be less.

You need to wind the wire turn to turn, winding the speaker is a delicate and time-consuming matter, the main thing is not to abandon everything halfway ... I wound it with a wire of about the same cross section, in total I got 4 layers, each layer was covered with BF-2 glue and allowed to dry about two hours. It is not so difficult to determine the required length of a new wire with sufficient accuracy, you need to calculate the length of one turn (knowing its radius), multiply by the number of turns in the layer and by the number of layers. For my speaker, it took about 20 meters of enameled wire. The wire diameter is determined using a micrometer or caliper. For winding, it is better to use a specialized machine, which greatly simplifies the entire winding process, if there is no such machine, then you will have to wind the coil manually.

After the glue has dried, we begin to assemble the speaker. I note that it is highly not recommended to glue the centering washer and the suspension at the same time, because with a probability of 99% after the glue dries, your speaker will grunt. First you need to glue either a centering washer or a suspension (I glue the first one). That is, with a brush we coat the edges of the washer and the places of gluing on the speaker case, let it dry a little and carefully put the diffuser on the case so that the coil does not rub against the magnetic core.

From the first time it will be difficult, so you can coat the washer with glue not entirely, but only at several points, in case of successful centering, you can glue it.Next, we glue the suspension, when connecting the suspension to the speaker basket, it is necessary to center the suspension itself in parallel, so that there are no rustles and rattles during the course of the diffuser. After we add conductive copper wires(conductors) from the coil to the speaker terminals and let the speaker dry for 24 hours.

There is another, more exact variant centering the coil, but for this you have to remove the cap from the diffuser. After removing the cap, we put the diffuser with the coil into the basket, then we take A4 paper, cut it along the wide side into two halves and fold it into a tube of about the same diameter as the core of our speaker and carefully insert it into the slot between the core and the coil, then you can safely glue the centering washer with a suspension. After the glue dries, pull out the paper and glue the cap back.

Most of the dynamic heads are not intended for their disassembly and are, as it were, disposable (non-separable, of little use for repair) components of acoustic systems. In practice, it is often possible to successfully disassemble a speaker of a typical design and assemble it again. The main task is to soften the glue with which the many components of the speaker are held together, and to separate them from each other without injury and deformation.

If you have questions about rewinding speakers, ask them at, we will try to help!

To do this, you will need the following basic materials:

1. Suspension to match the dynamics

2. Any contact adhesive (Moment-1, 88)

3. Latex or diluted PVA

Hangers are supplied uncut as per internal size, and on the outside, because are used not only for the repair of 75 HDN. It must be cut to the desired diameter.

The cap is peeled off by soaking the glue with acetone. The place for gluing the suspension is cleaned (on the diffuser and holder). The diffuser is cut around the perimeter by 2 mm. With the help of strips of paper (plastic, etc.), the moving system is centered (the strips are placed in the gap between the coil and the core of the magnetic system). Contact adhesive is applied to the suspension, diffuser and holder (the suspension will lose its shape at the beginning, then return to its original position). And, armed with dexterous hands, we evenly lower the suspension onto the diffuser and holder. It is better to slightly pull the diffuser out of the holder so that it first lies on the diffuser, and then glue it to the holder together with it. We take out the strips, control the build quality and glue the cap. To do this, you can use PVA or 88 glue.

To facilitate the process, you can peel off the washer from the diffuser by soaking it with acetone (fortunately, the quality of the adhesives of our speakers leaves much to be desired), and solder the leads (or it’s better to replace them altogether).

It is possible, of course, to peel off the washer from the holder, using for this purpose the glue solvent 88 - ethyl acetate.

Then, you need to put the suspension on flat surface, smear the diffuser and suspension with glue, after which we lower the diffuser with the coil onto it. Then we apply 88 glue on the suspension, holder, and BF on the diffuser and washer, center the movable system using the above method and paste it.

good tone it is considered to fill in the place indicated in the figure with latex (or diluted PVA).

It is also good to make holes under the cap for better ventilation.

Prepared according to the materials of the portal www.diffuser.spb.ru

Acoustic systems are divided into active, passive, the difference is limited by the presence of sound processing chips inside, powered by electric current. Amplifiers, filters, interfaces for reading flash media, decoding compressed audio formats. In the latter case, the speaker system approaches the functionality of the player. Consider what to do when the speakers do not work. Speakers include a myriad of sound reproduction devices, readers are interested in how they repair speaker systems with their own hands. You will need special glue. When the USSR was BF 4, AK 20. Accordingly (the basis of the glue), solvents are selected. It will be necessary, disassembling, dismantling the connection, repairing the speaker system yourself.

The device of a typical acoustic speaker

The movable part with a rigid plate creates air vibrations that are perceived by the human ear.

Acoustic speaker classification

To repair speaker systems with your own hands, doubting how the device works, it is supposed to use the principle - do no harm. Regardless of speaker size speaker system formed by electrical, mechanical parts. The first is formed mainly by inductors. The second includes permanent magnet, membrane. Here is an incomplete classification of the speakers of acoustic systems.

• Electrodynamic playback devices form three classes, the concept of the presence of a magnet, a moving membrane combines:

1. Coil built according to the principle known to the owners (repairers) geysers. The magnetic ring, when the throttle voltage is applied, causes the membrane to move, according to the law of the supplied audio frequency current.
2. In tape role variable magnet performs a narrow corrugation. No coil, of course, inside. Speaker applications require matching transformers. A feature that identifies the type of speaker in the acoustic system.
3. Isodynamic loudspeakers include a square, round helix moving parallel to the membrane in the field of a permanent magnet.

• Electrostatic playback devices have no moving parts. The membrane oscillates without making translational movements. The speakers perfectly reproduce high frequencies due to their low inertia.

• Piezoceramic speakers exploit the effect of converting electricity into vibrations of a quartz crystal. It is clear that you cannot achieve high power of the device; the speaker is suitable for the purpose of reproducing high frequencies of acoustic systems. Main advantage technical solution in low energy consumption.
• Ionic dynamics are practically rare, the theory was developed in the 50s. The principle of operation is based on the modulation of gas ions by sound vibrations. Need to get electric arc. Ideas are being put forward to use a flame formed by positive, negative particles (air ions).

Readers are familiar with naturally occurring sound reproduction devices. Not always in the dynamics of the speaker system there is an inductor. Therefore, before repair, in the process, the master performs the correct classification of devices, properly carrying out the necessary operations.

The device of the speakers of the acoustic system

Partially touched the device. Let us consider electrodynamic models in more detail. The diffuser forms the support of the cap. Represented by the likeness of a wide horn, on which the coil is glued from the back. Directly to the cap of the membrane fit flexible copper wires that carry electricity, punching the diffuser from the inside. Soldering points are visible from the front of the speaker. The coil is light, it is required to provide a relatively small inertia of the system. Even the tuning fork for the first octave lies at a frequency of 440 Hz. It is clear that for fluctuations of the indicated speed, the moving part of the acoustics speaker must be light.

The magnet is fixed on the frame. Usually circular. An inductor runs in both directions in the hole, moving the cap-membrane assembly. Connecting wires make constant vibrations. A centering washer is used to position the moving part along the vertical, horizontal axis. Perforated piece of elastic material, centering the location of the cap, diffuser. The centering washer does not interfere with the displacement of the moving part along the axis of symmetry. Repair is ridiculously simple:

Since the membrane and cap do not break, the point is to check electrical installation, places for soldering wires, integrity of the coil.

The inductance is wound in the image and likeness of the old one. Each layer of turns is smeared with BF 4 glue. Poor-quality soldering is performed again. Select the appropriate inductance winding technique. Usually a special device is made, formed by two pairs of racks, standing on a long board opposite each other. Both are connected by axles. One contains the core of the new coil, the other contains the purchased wire. It is recommended to buy wire with varnish insulation. It is necessary to maintain the correct thickness. You can measure using a caliper.

Winding is carried out relatively quickly while the glue dries. The coils fit tightly one to the other, professing the principle of the shuttle. It is important to maintain the correct number of revolutions, properly position the conclusions.

Often you have to disassemble the speaker of the speaker system for repair. Stock up on solvent. Glued joints are wetted, waiting for a fixed time. Please note: the joints are carefully cleaned. It is done regardless of the glue used to assemble the speaker of the speaker system.

Speaker range

Loudspeakers speakers different types, each has a limited frequency range. Everyone works in their own way mechanical filter. However, it happens that you need to shift the range ... You can raise the resonance frequencies of the electrodynamic system by varnishing the centering washer. A 5–10% solution of CAPON, cellulose in acetone are used. The varnish is applied with a soft brush in a circle. Avoid misalignment of the moving part of the loudspeaker of the acoustic system. By sequentially performing operations, we will increase the resonance frequencies by 1.5–2 times, approximately one octave.

To lower the range, stick weights on the moving part. The correct ring of cardboard is attached to the back of the diffuser. It should be more precise to maintain the symmetry of the arrangement of parts. The sound pressure drops rapidly. The volume decreases, the range narrows from the high frequencies. However, in the resonance region, the loudspeaker will perform well.

You can expand the range in both directions (if there is no cap). In the center, from the front, a truncated cone is glued above the inductor of the speaker speaker. The mass is made as small as possible. Thin, thick paper impregnated with TsAPON varnish will do. Upper platform equal to the coil, the height is half the diffuser, the taper is 70 degrees. Due to the increase in the mass of the moving part, the resonant frequency drops, but the upper edge of the range rises, thanks to the rigid core, harder than the cone. The result is an expansion of the spectrum of reproduced sounds in both directions. The total increase will be one and a half to two octaves, the game is worth the candle. Take care to set up correctly electronic part: if there are passive filters on capacitors and resistors, they will limit (cut off) the possibilities of mechanics.

Masters raise sound pressure at the resonant frequency for an unshielded magnetic system. Try to find this or a similar installed ring. Then glue the second magnet on reverse side standing, the interaction of the fields will increase, therefore, the strength of the sound will increase.

The device of the speaker system is simple, which can break, they said. We hope the renovation goes off without a hitch.

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 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 have a fairly high-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 - 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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