Many music lovers know the situation: a loudspeaker installed in one of the speaker systems, suddenly begins to “wheeze.” An external inspection reveals nothing; when ringing, the tester shows what is indicated on the label, but the sound is annoying, sometimes driving you crazy. This malfunction is especially typical for those with a large stroke. What's the matter?
A regular radio repair shop will advise you to simply replace the loudspeaker with a new one. This is a solution to the problem. It is simple but expensive. You can buy a good powerful head, and even a branded one, but it costs a lot. It will always be done in time. In the meantime, you can try to repair the speaker yourself.
As a rule, wheezing that occurs when playing the bass spectrum of sound frequencies is caused by short-term disruptions in the contacts connecting the coil to the speaker cable. In the place where thin, literally hair-like wires glued to the surface of the diffuser are connected to thicker elastic cables leading to the block, metal tin fatigue gradually accumulates during sound reproduction.
Repairing a subwoofer speaker, which most often suffers from this disease, is not difficult, but requires care. Usually the joint is filled with a drop of compound, so you need to pick it out very carefully, preheating it with a soldering iron. Once the connection is exposed, the contact should be soldered very carefully and quickly. After checking, if everything is in order, the repair area should be re-filled with an insulating compound, nail polish or viscous glue.
Speaker repair may also be necessary in cases where vintage or antique radio equipment over half a century old is being restored. For example, someone got an old American tube receiver from the post-war years. The condition is quite working, but the diffuser is badly damaged. You can, of course, simply replace the loudspeaker with a similar modern one. But you want to achieve “that” sound, to feel the time. In general, there is a desire to save as much as possible original elements scheme.
Repair of a speaker with a broken or torn cone is carried out using the gluing method. The best material, which serves to apply such a “plaster”, is Scissors should cut the patch so that it matches the shape of the missing fragment with an overlap of half a centimeter. Since rigidity is good quality diffuser, then it is best to glue the restoration part to it acrylic varnish for nails. Where its edge adjoins the ring holder, rigidity, on the contrary, is inappropriate, the movement should be as free as possible, so it is recommended to restore the semicircular edge rubber glue, like “eighty-eight”. We can assume that the speaker repair is complete; all that remains is to let the varnish and glue harden and polymerize.
A common malfunction of loudspeakers is the wear and failure of the corrugated ring suspension, usually made of porous rubber and holding the diffuser along the edge. Repairing the speaker in this case involves removing the old one and gluing a new elastic ring. Kits for this procedure are sold, but it should be borne in mind that only expensive loudspeakers deserve such painstaking work; you shouldn’t bother with cheap ones.
Detailed description diagnostics and repair of medium and high power speakers. The article was written for those who want to repair speakers and have winding and soldering skills.
I have been repairing speakers for 15 years and want to pass on the acquired skills and techniques to the Datagorians.
Sorry for the absence detailed photos process, all equipment and work are now a thing of the past. Has your speaker whined or stopped sounding and want to bring it back to life? First - diagnostics. We remove the speaker, disconnect the wires from the terminals, having previously marked the polarity. In the future, we adhere to this rule: everything that we disassemble, draw or photograph will help a lot.
We check the winding resistance with the device. There are three possible options here.
1) Break.
2) Nominal resistance.
3) Reduced resistance.
Now for the second check. Place the speaker on the magnet and carefully move the diffuser up and down. If you hear a rustling or creaking sound, or there is no movement, the speaker will have to be disassembled.
If there is no grinding, and the winding is broken - you need to check the conductivity of the flexible wires from the terminals to the soldering of the winding. They are made of threads intertwined with copper strands, which break down over time. They can be replaced without disassembling the speaker with M.G. wire. T.F. suitable section or braided tape to remove excess solder.
We solder the wires so that they do not stretch when the diffuser moves and do not touch it. We glue the soldering area with Moment glue.
If the speaker needs to be disassembled, disconnect the wires from the terminals, place the speaker on the magnet and use a swab soaked in acetone to soften the glue around the protective cap and remove it by prying it off with a non-sharp scalpel. Using the same method, peel off the outer edge of the diffuser and the outer edge of the centering washer. Carefully pull out the diffuser vertically upward without distortion.
I do not recommend unsticking the coil frame from the diffuser and the centering washer, so as not to disturb the alignment of the speaker.
To rewind you need to assemble a simple device, the structure of which is clear from the figure. The most difficult part is the reel mandrel. To make it you need to contact a turner. Mandrel length 100-150 mm, material – any metal.
Measure the inner diameter of the coil (x). The spool mandrel should have a diameter of x+0.5mm on one edge and x-0.5mm on the other edge.
At the larger end we drill a 3.2 mm hole and cut an M4 thread for attaching the handle.
Drill a 6.5 mm through hole for the stud. The surface of the mandrel must be sanded.
Now you can start winding. We will need alcohol-based glue, for example, BF-2 or BF-6, paper from the MBM capacitor, wire and a lot of patience.
We dilute the glue with alcohol. We pierce the centering washer with a needle, thread the winding wire and solder it to the flexible wire. We fix the wire at the soldering point and at the beginning of the winding, gluing pieces of paper.
If the coil frame is made of metal, we paste it with a layer of capacitor paper without overlapping layers. We wind the wire turn to turn, gluing it before winding and over it. Remove excess glue with your finger. We try to wind it not tightly, but tightly.
On the first layer we glue the paper from the capacitor without overlapping layers and perform the same steps in reverse order. When the winding is ready and soldered to the terminals, you need to connect them to a 4-5 Volt power source with a current of 1-2 Amps for drying. The winding will heat up to 50-60 degrees, while the glue will dry and harden, the coil will expand slightly. This will help you easily remove it from the mandrel.
We check the free movement of the coil in the speaker gap and begin assembly.
We need to align the coil exactly in the center. There are 2 ways to do this.
1) Place a spacer made of photographic film or x-ray film into the gap.
2) Apply a small constant voltage of 2-3 Volts to the coil so that it is pulled inward a little.
Apply a layer of Moment glue to the outer edge of the diffuser and the outer edge of the centering washer and lower the diffuser vertically down without distortion and without radial displacement, and press it. You can turn the speaker over onto a flat table, and while the glue dries, solder the wires to the terminals.
After the glue has dried, remove the gasket and check the free movement of the coil in the speaker gap.
If everything is in order, glue the protective cap in place and enjoy the result!
Thank you for your attention!
The speaker coils are wound turn by turn until the specified coil length is obtained. In this case, as a rule, the number of turns is not counted.
When winding, maintain constant tension on the wire and carefully lay out the turns. The turns of the second layer are laid out especially carefully, when each turn must be strictly laid between the turns of the first layer.
To make it convenient to carry out such precise work, take care of the hand rest.
The coil with winding wire can be secured in any way convenient for you and installed on the floor.
More about it a simple machine for winding speakers you can read.
Another useful tool, which will be needed for winding the coils, is this kind of clothespin with a weight.
The required adhesive viscosity can be achieved by adding small quantity alcohol with thorough mixing.
Expand the player to full screen to see the video in full resolution.
Before the main winding, several extra turns are wound onto the sleeve in order to securely fasten the wire and sleeve to the surface of the template. Then, during the next extra turn, an even layer of glue is applied to the sleeve with a brush.
After this, the first layer of the coil is wound quickly. Then a weight is attached to the wire, which allows you to maintain the necessary tension on the wire and free up your previously occupied hand. Then, the first layer of the coil is covered with glue.
At this stage, do not try to secure the end of the wire by winding it around some object!
Any excess bend in the wire can increase the size of the coil, thereby reducing the external air gap.
If you still cannot avoid kinks in the wire, then pull the problem area through your thumbnail several times.
After fifteen to twenty minutes, when the glue has dried, you can begin winding the second layer.
First, one or two turns of the second layer are wound, and then the first layer of the coil is covered with glue. This is done so that the fresh glue does not dissolve the glue applied earlier, and the first turn of the second layer does not fall into the gap formed between the outer turns of the first layer.
After winding the second layer of wire, the coil is dried for 10-15 minutes and then covered with glue again.
When the glue dries well, you can either remove the coil from the mandrel along with the sleeve, if it is already glued into the diffuser, or glue it into the diffuser directly on the template.
However, in some cases, the sleeve is glued into the diffuser already during speaker assembly.
To remove the sleeve from the template, the place of the gasket where the fixing drop of glue was applied is cut off, and the sleeve is removed from the mandrel along with the spool and gasket.
If the gasket does not slide along the mandrel, it means that the wire tension during winding was too high. It should be noted that excessive wire tension can reduce the gap between the sleeve and the core and make speaker assembly impossible. This is because copper wire can stretch and contract like any other metal.
Since there is a gap in the sleeve, when winding the coil, glue penetrates into it and the sleeve is glued to the gasket.
In order to separate the gasket from the sleeve, it is enough to use a brush to lightly moisten the place where the gasket is stuck to the sleeve with acetone or alcohol.
Now our coil is ready. Now it should be completely dried.
For final curing of the glue, the reel is fed electricity. The current strength is selected to achieve optimal mode curing.
The temperature during the drying process can be measured with an electronic thermometer.
If there is no suitable power supply, then the coil can be connected to the ULF and a signal from the Low Frequency Generator (LFO) can be applied to its input. The link to the software LFO is in the “Additional Materials”.
Curing mode for adhesives “BF-2”, “BF-4”.
Leave for 60 minutes. at room temperature.
Then 15 min. at 55... 60ºС.
Then 60 min. at 85... 90ºС.
You can often come across requests for help in repairing and rewinding the coils of burnt-out speakers; articles on this topic have been on the Internet for a long time, but we decided to make our own. So, I got my hands on a burnt-out Pioneer subwoofer speaker from a TS-WX303 subwoofer; the rated power of the speaker is about 250 Watts. I think that former owner I overdid it with power and as a result our speaker burned out.
When you press the diffuser, a clearly audible grinding sound is produced, this is the coil rubbing against the magnetic core, possibly falling apart, after disassembling the speaker everything will become clear. The main difficulty is to disassemble the speaker, because it is very important not to damage the speaker suspension, it’s good when the suspensions are rubber, such ones come off and come 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.
Personally, I disassemble speakers in one of two ways: with a thin blade, or by soaking them in a solvent. In the second case, you need to work strictly outside or in a well-ventilated area, but not at home or in the entrance. You need to prepare in advance all the tools necessary for repairs, perhaps 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 outer parts of the suspension, in the place where it is glued to the “basket”. Soaking usually takes a long time; in 5 minutes you will not separate the suspension from the speaker body. The centering washer is soaked in exactly the same way.
This is not the first time I have rewinded speakers, and the dismantling operation for this speaker took me about 5-7 minutes. After soaking, we unsolder the conductive wires from the terminals and remove the diffuser with the coil from the frame. In principle, it is possible and necessary to unsolder 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 unwinded completely and rewound again. some unscrupulous repairmen practice next view repair: unwind part of the burnt wire and connect the break points together by soldering. Naturally, such a “homeless repair” will not last long; in addition, after unwinding some of the turns from the coil, it will noticeably reduce the total 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).
Ideally, the speaker coil should be wound with BF-2 glue. It's not easy to find, but it's the most the best option. We glue the suspension with rubber glue 88, it is usually sold in small jars in construction stores, this glue is used to glue carpets onto subwoofers:
Finding the right wire is also a problem, good wire donors are contactor (starter) coils, which are sold separately in electrical equipment stores and are not expensive, this is exactly the wire I use. The required wire can also be found in the demagnetization loop of picture tubes (CRT), a sample of my wire for winding is shown below in the photo:
I removed this wire and rewound it just from the starter, the diameter of the wire is approximately 0.35, by the way, it’s too much to rewind thin wire not recommended because The speaker power will drop sharply. If you take a wire thinner than it was, then you will have to make a little more turns than there were, otherwise the resistance of the speaker will be less.
You need to wind the wire turn by turn, winding a speaker is a delicate and labor-intensive task, the main thing is not to abandon everything halfway... I wound it with a wire of approximately the same cross-section, I got 4 layers in total, covered each layer with BF-2 glue and let it dry for about two hours. Determining the required length of a new wire with sufficient accuracy is not so difficult; you need to calculate the length of one turn (knowing its radius), multiply by the number of turns in the layer and the number of layers. My speaker required about 20 meters of enamel wire. The diameter of the wire 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 you don’t have such a machine, you will have to wind the coil manually.
After the glue has dried, we begin to assemble the speaker. I note that gluing the centering washer and the suspension at the same time is highly not recommended, because with a 99% probability, after the glue dries, your speaker will groan. First you need to glue either the centering washer or the suspension (I glue the first). That is, we coat the edges of the washer and the gluing points on the speaker body with a brush, let it dry a little and carefully put the diffuser on the body so that the coil does not rub against the magnetic core.
It will be difficult the first time, so you can coat the washer with glue not entirely, but only at several points; if centering is successful, you can re-glue it.Next, we glue the suspension; when connecting the suspension to the speaker basket, in parallel, you need to center the suspension itself, so that there are no rustling or grinding noises when the diffuser moves. Afterwards we solder the conductive ones copper wires(conductors) running from the coil to the speaker terminals and let the speaker dry for 24 hours.
There is another, more exact option centering the coil, but to do this you will have to remove the cap from the diffuser. After removing the cap, we put the diffuser and coil in the basket, then take A4 paper, cut it along the wide side lengthwise into two halves and roll it into a tube of approximately the same diameter as the core of our speaker and carefully insert it into the gap between the core and the coil, then You can safely glue the centering washer with the suspension. After the glue has dried, pull out the paper and glue the cap back on.
Most dynamic heads are not intended for disassembly and are, as it were, disposable (non-separable, difficult to repair) components of speaker systems. In practice, it is successful to disassemble the speaker standard design and it is often possible to reassemble it. The main task is to soften the glue that holds many components dynamics, and separating them from each other without injury or deformation.
If you have questions about rewinding speakers, ask them here, we will try to help!
