Manufacturing of structural parts and assembly of emitters. Membrane. Mylar film from K73-16 capacitors is well suited as a membrane material. This is a wonderful base in many ways, with the exception of one drawback - its width is only 35 mm, which imposes certain restrictions on the area and shape of the membrane. In capacitors on operating voltage 100 V film thickness is 4...5 microns.

How to make your own headphones

This is quite enough for an amateur design. After all, even with such a film thickness, its mass, as follows from, is comparable to the mass of oscillating air. The capacitance value of the capacitor does not matter; it is important that the length of the capacitor body is 48 mm. This is the maximum possible size, and the width of the film removed from such a capacitor is exactly 35 mm.

Of course, if it is possible to use a film with similar properties suitable sizes, then the task of manufacturing a larger-sized membrane is significantly simplified. However, the option with a capacitor film, although problematic from a technological point of view, is quite accessible and requires separate consideration. To do this, you can refer to, where the manufacture of a membrane for TDS-7 phones is described in detail. In relation to this case, the revised part of the description looks like this: Carefully saw along the capacitor body and take out its “filling”.

Rewind and delete initial part a roll 20...30 cm long, where a thick film is used as a dielectric. Next, the working part of the capacitor actually begins, which consists of two films folded together (capacitor plates). We cut a strip 15 cm long from the roll. Using a sharp scalpel, we separate the films from each other. The main difficulty is to “catch” to the beginning of the section of films fused together.

Next, to facilitate the process, you can drop a few drops of acetone into the gap formed between the films. After the films are separated, the metallization should be removed from them. In this case, you can use ordinary bleach, the process time is 20 minutes.

After which the films should be thoroughly washed, dried and ironed with a hot iron (temperature for wool) through a sheet of paper, preferably just between the sheets in a book. The output of the process is transparent, even, smooth films suitable for use. To obtain the desired width of the membrane, the resulting two films must be glued together. Unlike the method described in this case, gluing must be done overlapping.

Let's do it like this.

Place the pre-prepared films, as described above, on a flat smooth surface and connect them together with long sides with an overlap of 1.5...2 mm. Holding them in this position and bending one of the sides, we apply BF-6 glue a little at a time (literally in micro portions) along the line of film overlap. You can press immediately. In this case, it is better to start gluing from the middle. This method is more labor-intensive than others, but in terms of seam strength the result is much better.

In addition, the adhesive layer is protected on both sides from the active influence of the working coating (spraying) of the membrane. To eliminate irregularities, the film thus obtained must also be ironed again. In this case, the adhesive seam should be isolated from the paper with Mylar film (from a roll), otherwise the heated glue, if it ends up outside the seam, will stick to the paper sheet. After heat treatment, microfolds may appear on the film as a result of eliminating irregularities. The main thing is that the resulting film should be completely flat without bulges or warping. One should not hope that in the future, when stretching it on an insulator, such defects will be corrected.

The thickness of the adhesive seam after smoothing with a heated iron is approximately 20 microns, and its influence on the total mass of the film is minimal, and the strength of such gluing is quite sufficient.

After trimming, a workpiece with dimensions of 70x120 mm is obtained with an adhesive seam running along the axis of symmetry (Fig. 2). It should be added that it is better to stock up on such semi-finished products for future use so that in case of failure you do not have to repeat the whole process again.

Despite the fact that the film removed from the capacitor is initially metallized, the issue of coating the membrane is not decided in favor of its native conductive coating. And there are two reasons for this. Firstly, one-sided metallization, as in this case, leads to curling of the film, which is practically impossible to eliminate, which is very inconvenient to work with and ultimately leads to warping of the membrane.

Secondly, extremely thin layer metallization is prone at fractures, in particular at the output lobe, to complete loss of conductivity, which, in turn, leads to loss of performance of the entire emitter as a whole. Therefore, removing metallization, as described in, does not contradict the general idea in this case.

So, the semi-finished product in the form of a smooth, without signs of warping, transparent film with the indicated dimensions is ready, and now you can proceed to the next stage - the stage of membrane spraying. Judging by the debates on thematic forums, the technology for manufacturing proprietary membranes remains a secret, and, perhaps, they are not feasible at the amateur radio level, nevertheless, there are a lot of ideas. One of the most affordable methods of coating a substrate is spraying antistatic agent “Lana” or other similar ones in their own way. physical properties aerosols.

This coating is classified as high-resistivity, and its resistivity- 2…5 GOhm/cm². And despite the fact that such a coating is presented as a trial, temporary one, in fact the end result in relation to GT can be quite acceptable. Thus, almost all prototypes, subject to the manufacturing technology, worked without serious complaints about such deposition. However, it was not possible to estimate the lifetime of such sputtering.

Some samples worked successfully for more than a year without reducing sensitivity, after which, one way or another, they underwent modernization. It should also be noted that such membranes are unpretentious to storage in the cold (-30 °C) or at elevated temperatures (+50 °C). 100% humidity (followed by drying) is also satisfactory. Over time, the resistivity of such a coating tends to increase, which can lead to a noticeable increase in the time of charge accumulation on the membrane from the moment the polarizer is turned on.

The spraying process is quite simple. First you need to make a protective frame from thin, even cardboard. The frame is needed so that the jet from the sprayer hits only the working area of ​​the film. In Fig. 2 this area is highlighted gray. It is better to reduce the internal dimensions of the frame by 0.5... 1 mm to limit the transition area of ​​deposition. The indicated cuts on the membrane petal are made immediately before stretching it on the insulator or during the stretching process, in place. We apply the frame to the film and spray it from a distance of 20...25 cm.

This should be done moderately, so that there are no sagging on the film. The antistatic agent is active against BF-6 glue, but the latter is already protected by layers of films. The operation must be repeated twice with an interval of 2 hours. In the same way, spray and the opposite side membranes. It is recommended to cover the petal with an additional layer or even two, since problems associated with decreased sensitivity due to

Self-tapping screws with flat heads are easy to use specified diameter, clamped along the thread by the “crocodiles” of the voltmeter. Of course, these voltage values ​​are approximate and depend on the properties of the antistatic agent, which may differ depending on the different manufacturers. In this case we are talking about the products of the Novomoskovsk plant. If necessary, the number of spray layers can be increased. The principle is simple - the thinner the layers, the more there are.

But an antistatic agent such as Lyra is less preferable. A coating based on it has a noticeably higher resistivity and may ultimately be comparable to the leakage resistance of the entire structure, which will complicate the task. For example, in the previous measurement scheme, the voltmeter readings may be in the range of millivolts. In addition, Lyra is more sticky, which creates certain problems.

Fixed electrodes

From one-sided foil-coated fiberglass laminate with a thickness of 1.5 mm, we cut out two identical blanks according to the dimensions of the finished electrode, as in Fig. 4. Both NEs - internal and external - are the same, except that on the external (farthest from the ear) electrode, instead of mounting holes with a diameter of 2 mm, as shown in Fig. 4, do threaded holes M2.

There is no need to drill the mounting holes yet. But to drill holes for perforation when using a stationary drilling machine possible at the same time. To do this, both parts must be pressed together with foil sides and a stencil must be applied to them. The package thus obtained is secured with miniature clamps. Holes should be drilled within the boundaries of the foil area, with the exception of the outlet petal.
At the end of drilling, the package is separated, burrs on the drilled electrodes are removed with a small needle file and sandpaper. After this, you may have to go through all the holes again with a drill to clean out the holes. Ultimately, the working surfaces of the NE must be, as they say, in perfect condition. If you intend to use a hand-held electric drill, then in order to avoid possible distortions It is better to drill NE holes separately, one at a time.

The next stage is the production of insulators. To do this, you will need one-sided foil fiberglass (use of getinax is allowed) with a thickness along the width of the selected gap. Let this be a compromise option from the previously indicated values, for example 0.8 mm, from the standard range of fiberglass laminate grade SF-1. Of course, the gap and thickness of the NE can be chosen differently based on available materials or for other reasons.

This will basically only lead to a change in the thickness of the emitter, which is easy to take into account in the future. The sensitivity is adjusted by selecting the polarization voltage. For one emitter you will need two parts - A and B, as in Fig. 5. Insulator B is shown only in fragments (lower part), and non-foil fiberglass laminate can also be used for its manufacture, otherwise the parts are identical.

You can cut the insulators with a regular cutter, having previously drilled holes in the corners with a thin drill. Afterwards, the foil should be removed, with the exception of the area highlighted in color (Fig. 5), this is the contact pad for gluing the membrane petal and soldering the cable conductor.
The cutout in the lower part of insulator B is designed to prevent the adhesive contact between the membrane petal and the contact pad from being deformed when assembling the package. If foil fiberglass laminate of the specified thickness is not available, the contact petal can be cut out of copper foil and glued in place universal glue"Moment".

Then epoxy glue(plasticizer is required) glue the insulators to the inner (foil) sides of the stators, and the petal of insulator A should be directed in the same direction as the foil side of its stator. In order to save material, insulators can be made from individual strips 5 mm wide. In this case, it is better to use a mandrel in the form of a thin rectangular plastic plate with dimensions of 50×85 mm, which guarantees good repeatability internal dimensions insulator frames. After drying, possible sagging of epoxy glue on the working surfaces of the stators must be removed.

Now you can drill the mounting holes and it is better to do this simultaneously on both NEs, precisely aligning them with insulators to each other and securing them with clamps. First you need to drill out through holes with a diameter of 1.5 mm. Then disconnect the NE and drill holes up to 2 mm on the inner (closest to the ear) electrode, and cut an M2 thread on the outer one using the first tap number. Ultimately, the package will be held together with M2 screws 5 mm long with a countersunk head. Therefore, on the outside of the internal electrode it is necessary to make countersinking holes for the screw heads. Threads in fiberglass laminate have reliability limitations, and this must be kept in mind when assembling the package.

Upon completion of all work related to machining, parts should be thoroughly cleaned of dust and degreased. Before painting conductive surfaces, NE insulators must be protected with adhesive tape from paint getting on them. After painting, you should pay attention to the quality of the coating. Hard inclusions protruding above the surface, which sometimes still occur, must be cleaned off.

Emitter assembly

At this stage, first of all, you should correctly stretch the membrane, which is attached to the NE with insulator A. This important point, on which the success of the work as a whole depends. Stretching the membrane itself is not so complicated or time-consuming. It is much more difficult to adjust its tension when you have to partially peel off the membrane. In this case, film tears are possible. Therefore, it is desirable that the required result is obtained the first time. You can first practice on a dummy - uncoated film, which you don’t mind. Acquiring a certain skill plays a decisive role. In extreme cases, you can use a film with a thickness of 10 microns. This film is used in K73-16 capacitors for a rated voltage of 400 V.

The prepared membrane is carefully placed on the stator so that its sprayed part is exactly above the perforation of the electrode, and its petal coincides with the foil section of the insulator. In Fig. 6 numbers indicate the sequence of actions.

First, at point 1 on the end side of the stator, apply a smear of universal “Moment” glue and after 10...20 s, bend and fix the upper edge of the membrane on it. Next, at points 5 and 8, you also need to apply light dotted strokes of glue on the end. After exposure, fix the lower part of the membrane with moderate tension in the direction of the arrows. There is no need to be particularly zealous with glue.

The film is lightweight and holds well even with minimal use. After waiting for about 10 minutes, lightly coat the end sections 1-2 and 1-11 with a thin layer of glue (hereinafter indicated by thick lines). Again, hold for 10...20 s - and the upper edge of the membrane is folded onto the end of the NE with simultaneous tension in the direction of the arrows. The same operation is performed with bottom membranes (areas 5-6 and 7-8).

Thus, the vertical stretch is completed. In this case, the middle part of the membrane should be flat, longitudinal (vertical) waves can only be at its edges. After a longer exposure of up to 30 minutes, you can do a wide stretch. To do this, apply a thin layer of glue to section 3-4 of the stator end along its entire length. Hold for 10...20 s - and also bend the side edge of the membrane to the end along the entire length with a tension slightly greater than necessary to eliminate waves.

Again, hold for 10 minutes, after which the opposite edge of the membrane is glued to the other end of the electrode in the same way (section 9-10). The result of the work performed should be a completely flat membrane without waves or folds. You can blow lightly on the membrane, making sure that there are no vibrations in its individual sections. The higher quality the membrane is made, the less problems when stretching it.

Moment glue holds membrane tension well, while allowing you to correct possible defect. To do this, you will need acetone, but it should be used in minimal portions so that it does not flow onto the sprayed part of the membrane, otherwise leaks may occur, which can often be eliminated only by replacing the membrane itself. But if the defect is noticed even at the moment of gluing, when the glue has not yet completely adhered, then you can quickly separate a section of the film from the insulator without resorting to acetone. A NE with a membrane stretched on it is shown in Fig. 7.

Now you can roughly evaluate the quality of the membrane tension by listening to its resonant response when you tap the electrode with your finger. A “flabby” sound indicates that the tension is too weak, while a ringing sound, on the contrary, indicates that the tension is too high. The sound should be low in tone and elastic. Generally speaking, it is better to over-tighten the membrane slightly than under-tighten.

Ultimately, the somewhat larger losses at frequencies below 40...50 Hz are not as important as the consequences of a membrane that is too loosely tensioned. These include a rather unpleasant phenomenon that occurs when the gap is small or due to excessively weak tension of the membrane - its relaxation vibrations, and sometimes sticking to one of the NEs. The reason for this phenomenon is that in the event of an asymmetry in the position of the membrane in the gap, a difference force acts on it, tending to attract the membrane to the NE that is closest to it at the moment.

But as follows from communications on Internet forums, even branded products are not immune from this. Then, at the point of contact of the membrane petal with the foil section of the insulator, a little conductive glue should be applied so as to ensure contact with the foil of both sides of the membrane petal, cutting off its excess, as shown in Fig. 8 (fragment of NE).

Such contact, despite its apparent dubiousness given the oily properties of Lana, is in fact quite reliable. The remaining free corner of the insulator lead is intended for soldering a conductor with a polarizing voltage of +Uо. You can also prepare a conductive adhesive paste yourself by thickly mixing fine copper filings filed with a file into a drop of PF-283 varnish. This paste hardens quickly and should be prepared immediately before use.

Subwoofer headphones are especially popular among professionals and music lovers. These headphones deliver clearer sound that allows you to enjoy your favorite music. However, not everyone can buy subwoofer headphones, since they cost a lot of money. What to do if you have a great desire to acquire such headphones, but do not have the appropriate funds? You will find the answer to this question in this material.

And first, we suggest you familiarize yourself with the author’s video

What do we need:
- round headphones;
- speakers;
- construction tape;
- screws;
- cotton wool;
- glue gun.

Let's start right away with the shape of the headphones. It depends entirely on the shape of the speakers. The author uses round speakers, so his headphones have round shape. As for construction tape, we don’t need all of it: we need a cardboard tube, that is, its base. The speakers can be removed from the TV, as the author does.

First we need to disassemble the headphones. It needs to be almost completely disassembled. We throw out the old speakers from there, that is, plastic with wires and rubber elements remain.

We cut off the old wires and connect new ones with connectors for the new speakers. If there are none, then you can leave the old wires, but in this case you will have to solder the new speakers with a soldering iron.

For greater convenience, you can remove the plastic mounts of the new speakers and use them between the speakers and the rubber elements.

We take a cardboard ring from an old scotch tape and divide it in half.

For greater aesthetics, you can wrap the rings with red electrical tape, as the author does.

Let's start assembling the headphones. First, we screw the speakers to the plastics.

We put the rings on the speakers and connect the wires. We check if everything works as intended.

Apply a layer of hot melt glue to the plastic parts of the headphones.

Glue the first ring.

We stuff cotton wool in there.

Apply another layer of glue to the ring, and then glue the speaker itself.

We repeat the same with the next speaker.

We put on the rubber parts.

Subwoofer headphones are ready. Finally, we note that new design headphones can harm the hearing mechanism if you listen to music for too long and too loudly. The fact is that the new speakers transmit more low frequencies, so you need to be extremely careful and follow all safety rules. Headphones should not be used with an amplifier.

The design of these homemade headphones uses 0.25GD dynamic heads without any modifications. The ear pads and cushions are made of rubber sponge (you can buy it at the pharmacy). For heads with a diffuser diameter of about 55 mm, jaws measuring approximately 155 x 90 x 35 mm are suitable.

First, take a piece of pressboard or hard cardboard measuring 130X130 mm. A hole is cut out in it and the head is glued into it (Fig. 1).

Fig.1. Dynamic head panel:
1 - cardboard, 2 - head, 3 - leads

Then a recess for the speaker housing is cut out (or plucked out) in the ear cushion sponge (Fig. 3), and an oval-shaped hole is made in the cushion sponge (Fig. 2). Its inner edge is cut off from the side adjacent to the ear.

Fig.2. Sponge pillow.

Rice. 3. Sponge-embouchure with a recess of the head under the body.

Solder the lead wires and, if necessary, an additional resistor, the resistance of which is selected experimentally depending on the power of the amplifier. Several holes are punched in the cardboard panel and wires are passed through them.
The surfaces of the sponges and panels are covered with glue and allowed to dry. After this, glue is applied again and all three parts are connected to each other, after passing the wires out. The finished earphone should be placed under a press for several hours until the glue dries. So that it doesn't happen short circuits which can damage the ULF, pass the wires through a sponge using an invisible pin.

The second phone is made in the same way.

The headband is a piece of rubber band about 5 cm wide (it is also sold at the pharmacy).
A decorative overlay is glued to the outer side of the ear pad, under which the headband tape will lie (Fig. 4).

1 - rubber band, 2 - leads.

Now all that remains is to solder a three-wire connecting wire with a connector to the head pins, and the stereo phones are ready for use.
You can connect the phones using steel tape or use a ready-made case from old headphones that have become unusable.

Fig.5. Appearance ready-made headphones made by yourself(phones are upholstered in velvet).

If you have trash that you would hate to throw away, then this article is just for you. All the component materials were given to the author of the homemade product completely free of charge, and for this reason you will only benefit.

Once upon a time the author had Explay headphones and a Prolife BT55 stereo Bluetooth headset. In the picture you can see that the headphones were missing some of the wires, and the headset was making wheezing sounds, that is, the speakers were completely faulty.

First of all, let's sort everything out. We didn’t even need a screwdriver for this operation, because all the fasteners are ordinary latches.

You need to remove the remaining wires from the headphones, unsolder the speakers from the headset and remove the battery for a while. We do this so that it is possible to get the wiring; it is located in the headphone housing.

As a result of the manipulations done, the headset only has a block with buttons and internal contents.

Next we need to attach the block with buttons to our existing headphone body. This is done very easily.

After the cover has been removed, you can see that the space underneath is identical in diameter to the existing button block.

The last task at this stage is just to remove the wiring.

After we have separated the internal contents, we process the entire body so that it matches the size of the lining.

Let's try this case on the body of the existing headphones.

Next you need to unsolder the mini-usb socket intended for charger and the author figured out how to make a small adapter from this socket to the socket that previously belonged to mobile phone nokia.

It turned out that the socket fit perfectly in that small hole that was previously intended for the wire.

Next, you need to make a small hole for the microphone using a drill.

After installing the board in place and securing it and the accompanying parts in place using hot glue, what came out was what you can see in the picture.

This photo is from the front. Here the author made a small mistake. It’s just that when he was drilling holes for the microphone, it turned out that he slightly touched the body with the cartridge.

As soon as the glue has hardened, we immediately attach the speaker itself using a soldering iron, and after that we close the case.

Well, finally everything is soldered and you can snap the case into place. Now let's put the foam rubber pads in place and put them on charge in order to carry out the test.

The check shows us that the indicator lights up red, which means everything is working.

Due to the fact that these headphones are regulated using a wire, the author decided to leave everything as it is. The only thing you need to do is throw the wire behind your head while the headphones are on. The sound in the headphones has become much better and even much stronger than the headset had before. The buttons, as well as the microphone, perform their functions perfectly, which is good news.

Hello Dear friends. Today the subject of my review will be these inexpensive and high-quality headphones.
Let's start with the fact that I needed high-quality headphones for my computer. By the quality of headphones, I mean, first of all, high-quality sound and secondly, reliability and durability of the design. Naturally with a minimal budget.

After a long and painstaking task, such as looking through dozens of other models, reading hundreds of reviews, and choosing a price, I settled on this model. And as it turned out, I was right. Everything I needed was here. The sound is very high quality, the reliability of the design is simply amazing.
Unfortunately, I cannot convey the sound quality and listening experience to you through video. But you can believe my great experience that the sound is just super! And if you trust me and purchase this model, then I give you my word - you will definitely not be disappointed. The bass is smooth and soft. The sound is spacious and warm. The noise isolation of the headphones from external sounds is very good - little of the external noise can be heard through the headphones.
Well, I described the sound as best I could, now about the design. The headphones themselves are full size... Not small, not big - just what you need. After reading hundreds of reviews, I realized that most Chinese headphones have a flimsy and unreliable design. This is expressed in tearing off and bending the headphones themselves in the middle (on the jumper) or tearing off one of their “ears” or even the wire.

This model is protected from these factors and features due to its design. They can easily be bent in the middle and there will be nothing wrong with them, as you can see. The headphones are trimmed with artificial leather, very pleasant to the touch. The headphones have a universal size and adapt to the size of any head.

Another defect with most headphones is the wire coming off or even being pulled out. This especially often happens when a person is sitting with headphones on at the computer and suddenly gets up and forgets to take off the headphones. I think this is familiar to many. Look at this high-quality wire with protection against fractures - to tear it off you need to apply more than tens of kilograms. You definitely won’t be able to do this accidentally (tear off the wire).
You probably have a question - why are there 2 plugs and also USB? – I’ll answer: 1 plug is the headphones themselves, the second is the microphone. These are computer, gaming headphones with a microphone - here is a microphone. USB is a stylish backlight.

The headphones come in two colors: light and dark, I took the dark model. Headphone diameter 50 mm, resistance 32 Ohm, reproduced frequency range - 20-20000 Hz, sensitivity - 107 dB. The cost of headphones is around a thousand - for high-quality headphones, I think this is very cheap.

In general, you shouldn’t save on this and look for even cheaper ones. As you know: disappointment from low quality lasts longer than joy from a low price. So take it - you won’t regret it. If in doubt, add to cart. Thanks for watching this video. Like, subscribe to the channel - see you again.

Headphones -