By themselves, ordinary horn loudspeakers did not have a housing as such. That all changed when paper cone speakers appeared in the 1920s.

Manufacturers began making large enclosures that contained all the electronics. However, until the 1950s, many audio equipment manufacturers did not completely cover the speaker enclosures - the back remained open. This was due to the need to cool the electronic components of that time (lamp equipment).

Stone

The most commonly used are marble, granite and slate. Slate is the most suitable material for making enclosures: it is quite easy to work with due to its structure, and it effectively absorbs vibrations. The main disadvantage is that special tools and skills in stone processing are required. To somehow simplify the work, it may make sense to make only the front panel of stone.

It is worth noting that to install stone speakers on a shelf, you may need a mini-crane, and the shelves themselves must be strong enough: the weight of a stone audio speaker reaches 54 kg (for comparison, an OSB column weighs about 6 kg). These enclosures significantly improve sound quality, but the cost can be prohibitive.

The speakers are made from a single piece of stone by the guys from Audiomasons. The cases are cut from limestone and weigh about 18 kilograms. According to the developers, the sound of their product will appeal to even the most sophisticated music lovers.

Plexiglass / glass

You can make a speaker cabinet out of a transparent material - it's really cool when you can see the "insides" of the speaker. Only here it is important to remember that without proper isolation, the sound will be terrible. On the other hand, if you add a layer of sound absorbing material, the transparent body will no longer be transparent.

The Crystal Cable Arabesque is a good example of hi-end glass acoustic equipment. The cases of the Crystal Cable technology are made in Germany from 19 mm thick glass strips with polished edges. The parts are held together by invisible glue in a vacuum unit to avoid air bubbles.

At CES 2010 in Las Vegas, the redesigned Arabesque won all three Innovation Awards. “Until now, no other manufacturer has been able to achieve true hi-end sound from a speaker made of such a complex material. - wrote critics. "Crystal Cable has proven it's possible."

Glued wood / wood

Good hulls are obtained from wood, but here an important point must be taken into account: wood has the property of "breathing", that is, it expands if the air is moist, and contracts if the air is dry.

Since the wood block is glued on all sides, stress is created in it, which can lead to cracking of the wood. In this case, the housing will lose its acoustic properties.

Metal

Most often, aluminum is used for these purposes, more precisely, its alloys. They are lightweight and tough. According to some experts, aluminum can reduce resonance and improve the transmission of high frequencies in the audio spectrum. All these qualities contribute to the growing interest in aluminum from the manufacturers of audio equipment, and it is used to make all-weather speaker systems.

It is believed that making an all-metal case is not a good idea. However, it is worth trying to make the top and bottom panels, as well as stiffening partitions out of aluminum.

Probably not a single person can do without music. And when the music is always with you, it really cheers you up. In this article I will show you how to make your own music column.

To create our column you will need:
An amplifier, I bought it in a radio store at a price of 100 rubles. It is assembled on a high-quality PAM8403 microcircuit
Speaker (3w, 4 Ohm)
Few wires
Phone battery
Switch.
The soldering iron is small.
Housing, bought in a radio store for 60 rubles
3.5mm plug from broken headphones
Speaker grill taken from a broken speaker
Hot glue
Charging socket.
Stationery knife.

When all the components are in stock, you can start.

First of all, carefully cut out a hole for the switch with a clerical knife.

We put a switch on this place. It will keep from being on its own clamps. It looks like a box.

This switch differs from the usual size, it is about 1.5 times smaller than usual, it looks stylish and solid.

Next step. We make a hole in the front of the case, using the same knife, our speaker will be located there, it will stand at the top and be placed outside.

Let's check if the speaker fits well there. If all is well, then you can fill it with hot melt glue.

Now let's get down to studying the amplifier.

In the photo, I conveyed brief information about the amplifier assembly as quickly as possible.

First of all, we solder the sound input, this is a 3.5 mm jack, for example, from their old or broken headphones. Basic is a white wire, green and blue, right and left audio input to the amplifier.

After that we solder the output of the amplifier to the speaker, since I have only one speaker, I will not implement the amplifier a second time.

We immediately solder the power supply of the amplifier to the plus of the battery through the switch. Let's make a USB socket for recharging.

After you have taken out the socket to the side panel, you can start assembling the box. There are no difficulties, you just have to close the rear roof, we put protection against physical impact in front.

For a computer user, a laptop is undoubtedly a convenient, compact and fairly functional device. But, unfortunately, this device is not without flaws.

Surely many laptop and netbook users have encountered the problem of quiet sound reproduction through the built-in speakers of these devices.

If you can connect an external stereo system at home, then outside the home walls this is impossible and you have to limit yourself to headphones. In this case, there is no question of collective viewing of any film or series.

How to fix the situation?

Portable computer speakers powered by a USB port will help to correct this situation. Now on the shelves of stores there is a huge selection of these devices, but their quality can differ significantly.

The price of portable computer speakers powered by a USB port is quite low and affordable for a wide segment of the population. Despite this, the purchase of this device may be unsuccessful, since the sound reproduction quality of such a system will leave much to be desired. Oddly enough, but among the cheap devices of this class there are devices of very good quality, both in design and in the quality of sound reproduction.

Let's “open” a portable speaker system powered by a USB port and examine the electronic stuffing of this device. From the point of view of a radio amateur, it is curious to know from which electronic components such devices are assembled. The knowledge gained can come in handy when designing or repairing portable USB speakers on your own.

Let's disassemble portable multimedia USB speakers of the brand Sven 315... Despite their cheapness, this model of portable speakers showed good reproduction quality and sound power sufficient for sounding a small room.

Disassembly of computer USB speakers

Portable speakers are easy to disassemble. To open the case, you must carefully remove the front decoration panel.

In order to get the printed circuit board of the amplifier, you need to unscrew the fixing nut, which is hidden under the plastic knob of the volume control. After that, the electronic board can be freely removed from the housing.

Electronic filling

The composition of the electronic filling of the device turned out to be quite simple. An integrated circuit of a stereo amplifier based on a microcircuit is mounted on a small-sized printed circuit board LM4863D... With a supply voltage of 5 volts, this microcircuit can deliver 2.2 watts of output power per channel with a speaker voice coil resistance of 4 ohms. Based on the description (datasheet) total harmonic distortion + noise ( THD + N) at maximum output power is 1%.

Amplifier board and speaker

Based on these data, we can conclude that on the basis of the LM4863D microcircuit it is possible to assemble a fairly good stereo amplifier with a low-voltage power supply (5V) and an output power of 2 W for each channel. Many who are not yet familiar with modern microcircuits believe that instead of the LM4863D, the TDA2822 is suitable. It's a delusion! The TDA2822 is very power hungry (compared to the LM4863) and produces strong signal distortions at maximum power. Also, the optimal power supply for the TDA2822 is about 12 volts, which is not good for portable equipment. The TDA2822 can be recommended as a readily available replacement if the LM4863 is not available. This can happen, for example, during repairs.

It is worth noting that the LM4863 microcircuit was developed specifically for compact systems, so the microcircuit requires a minimum of external elements (the so-called strapping). The microcircuit is available in different packages, from the usual DIP to a compact SOIC.

If there is a desire to independently assemble an amplifier based on the LM4863 microcircuit, then you may encounter a problem. It is not so easy to find this microcircuit on the radio markets (this was the case at the time of this writing). But on the network trading platforms it was not difficult to find such a microcircuit. For example, in the online store AliExpress.com, the LM4863 microcircuit is easy to find in all kinds of cases and in any quantity. The price of 1 microcircuit is less than $ 1 if you buy 10 pieces at once.

How to buy radio parts on Aliexpress, I told you.

In addition to the amplifier microcircuit itself, the PCB has a connector for connecting a passive speaker (without a built-in amplifier), a double variable resistor for adjusting the input audio signal, and an electrolytic capacitor. On the side of the printed conductors of the circuit board, SMD strapping elements are installed, which are necessary for the operation of the integrated amplifier. The microcircuit is powered from the USB connector, which is connected to any free port of a laptop or stationary computer.

A typical connection diagram for the LM4863 microcircuit is taken from the description (datasheet "a) for this microcircuit and is shown in the figure.

Typical circuit for switching on the LM4863 microcircuit (taken from the description)

According to the typical switching circuit of the LM4863 microcircuit, it can be seen that it is capable of working on ordinary headphones ( Headphone), the resistance of which is 32 ohms. The microcircuit provides a circuit for determining the connection of headphones and 16 (HP-IN) pin is allocated for this function.

For those who are versed in electronics and datasheets in English do not scare them, the LM4863 microcircuits can easily be found on the Internet at alldatasheet.com.

Portable USB speaker amplifier circuit

The schematic diagram of the amplifier is manually mixed from the printed circuit board of the Sven-315 computer USB speakers. The diagram shows one capacitor C2 instead of the two (C7, C9) that are actually present on the PCB (see below). This is done because the capacitors on the PCB are connected in parallel (C7 and C9), and in the reduced diagram, the capacitor C2 indicates the total capacity of these two capacitors.

Schematic diagram of an amplifier based on LM4863D (mixed by hand)

As you can see, the typical circuit from the description differs from the one that is manually mixed from the printed circuit board of the amplifier of computer speakers. The diagram lacks elements that are installed if a headphone jack is added to the diagram. The rest of the circuit corresponds to the typical one given in the description for the LM4863 microcircuit.

Placing elements on a printed circuit board

If you plan to use portable speakers without a laptop, for example, in conjunction with an MP3 player, then a 5-volt power adapter is quite suitable for powering the speakers. The main thing is that the power adapter can provide sufficient load current (as an estimated rough guideline: the standard load current for USB ports is no more than 500 mA). According to the description for the LM4863 microcircuit, the maximum quiescent current (when no sound signal is applied to the microcircuit) is 20 mA. Naturally, during playback, the current consumption will be higher.

The photo shows a variant of powering SVEN-315 portable speakers from a 5-volt adapter, which is used to charge the iPod. The maximum load current of the adapter is 1A, which is more than enough for the regular operation of portable speakers.

As it turned out, high-quality sound reproduction of SVEN-315 portable speakers lies in the rational design of the case. As you know, the quality of sound acoustic systems is influenced not only by the loudspeakers used in them, but also by the housing. To verify this, just pull the speaker out of the case and start playback. The playback quality and sound power will be much worse. This remark was not made by chance, since the quality of sound reproduction of SVEN-315 portable speakers and similar, but more expensive SVEN PS-30 USB speakers was compared.

Despite the fact that SVEN PS-30 audio speakers are mounted on the basis of an integrated USB audio chip CM6120-S, which includes a 16-bit DAC and class D audio amplifiers, the quality of their sound reproduction is subjectively (by ear) much worse due to poor the performance of the speaker cabinet.

The case of SVEN-315 portable speakers is made of ABS plastic. Perhaps it is the design of the case that allows you to "squeeze" all their modest capabilities out of small-sized speakers.

This review focuses on the miniature 40mm speakers that I used in my homemade speaker. I must say right away that the speakers lived up to my expectations as tweeters and, together with the low-frequency one, gave quite acceptable sound for a fairly compact speaker.

It all started with a miniature subwoofer that came with the ASUS N55S laptop

I used it quite rarely, but despite this, the connector on the 2.5 "laptop to which this speaker was connected began to contact poorly and finally just fell into the laptop. I did not see any particular need for repairs, since the laptop was used mainly for work and didn't really need good bass.

But the thought, to use this column as a portable miniature speaker, has been in my head for a long time. Unfortunately, it was problematic to fit something other than this speaker into that case, so I decided to change the speaker case.

First, I wanted to assemble a speaker on a pair of half-watt speakers from old computers.

Their diameter was too large, and the sound was simply disgusting. Repulsive-creaky, and a little more loudness - sometimes strong-rattling. The woofer did not pull out the sound quality. Something else was needed. And here on the Internet I found the speakers from the review.
I bought them on EBAY, although it was possible on ALI and TAO:

Declared characteristics

• Diameter - 40mm
• Height - 20mm
• Magnet diameter - 22mm
• Rated power - 3W
• Resistance - 4 Ohm
• Frequency response - 170KHz
• Nonlinear distortion factor - 1%

Yes. The Chinese cannot live without exaggeration. The nominal (not PMPO, as they usually like to bring) power of 3W and the upper frequency of 170KHz especially smiled. It is rather difficult to check these characteristics, so we will leave them on the conscience of the seller.

Components used

• Speakers 3W 4 Ohm 40mm at the link above $ 1.9 x 2 = $ 3.8
• The case (left over from another project), if I bought it, I would have taken it without a transparent cover measuring 115x90x55
• - $ 0.99 for 2 pieces
• ~ $0.5
• Woofer 5W 4 ohm
• Battery from a faulty phone at 2200mAh

The speakers arrived in 29 days. Standard for delivery from China to Perm

Smaller size than speakers from computer cases.
Therefore, a 120x80x55 mm instrument case with a transparent cover, lying around idle, came up, which is absolutely superfluous in this product.

Dimensions correspond to the declared

Weight 25g (maybe someone with TAO will order)

Resistance is okay too

All speakers included

Miniature amplifier boards based on PAM8403

Lithium battery charging boards with 600mA current on TP4056 (current can be adjusted up to 1A)

The initial test of the speakers led to a little rattling at maximum volume, so I put a volume divider and a high-pass filter on a 0.1 mKF capacitor at the input

The final scheme turned out like this

Cut holes in the case for speakers, button and MiniUSB connector

We glue the speakers, install the board, solder the battery

We connect to the phone.

You can close the case

What can I say about the sound? The quality was a pleasant surprise. For such a small rattler, the sound is very loud and high quality. The sound can be slightly adjusted with the equalizer in the phone / tablet / computer. There is bass, normal highs.
Consumption 150mA at maximum volume, that is, approximately 0.5 W. With a battery capacity of 2200mA / h, it will be enough for 12-20 hours, depending on the volume. It is also possible from the network through any power supply unit with a USB connector or a computer.

The column suited us perfectly.

The Chinese would boldly write HiFi on it)))

It remains to work a little with the appearance. I cover the speakers with a mesh for the windows.

And I paste over it with a carbon-like film that was lying around somewhere in the closet. And now the finished product is the fruit of several evenings.

In the future, modify this column with a volume control, a battery charge indicator and replace the line input with a bluetooth module (or FM / MP3 / USB)

Read about all my crafts in

Sometimes it is necessary to announce an event where there is no 220 volt power supply, for example, in the forest or on a walk, and if for two people the volume of the phone may still be enough, then for a company of 3 or more people, a higher volume is definitely needed. Recently I was putting things in order in my stocks of radio components and other related things, I came across two used batteries from mobile phones. Immediately, the idea arose to collect what I had been planning to do for a long time, but could not find the time: a portable speaker for an mp3 player, or a cell phone with an input from the "Jack 3.5" plug.

I must say right away that the device works great with both a phone and a player. It was decided, of course, to solder the amplifier on a microcircuit, finding the right one took a little time, read reviews on the Internet and stopped at tda2822m... The microcircuit has only 8 legs, execution in a Dip case. Then I downloaded the datasheet for this microcircuit, there were 2 options for connecting the microcircuit - in stereo mode and in bridge mode, the latter is interesting to us, since there will be only one speaker. In addition to wiring diagrams, there were also PCB layout options. Here is the schema we need:

Diagram of a homemade portable speaker

The printed circuit board was "captured" from the screen, the picture was cropped and fitted with the background image in the sprint layout program in accordance with the real size of the microcircuit case. After that the picture was outlined, a 0.33 MkF film capacitor at the input was also added to the board, and this is what happened :

Then, as usual, we print it out, transfer the drawing to the printed circuit board and poison it. Then we tin the tracks, drill and start soldering. The microcircuit, in order not to accidentally overheat, did not solder it, but soldered the socket, and put the microcircuit in this socket after soldering. The cost of a microcircuit in our city is only 15 rubles. Then I was faced with the task of how to make it possible to charge both batteries at once from charging for the mobile, that is, so that they were connected in parallel, and later they could be turned on in series for a higher speaker volume. Then it was developed using a 6-pin two-position toggle switch, the charge-work switching circuit:

Power is supplied by connecting the charging plug to the speaker socket; with discharged batteries, you need to charge an hour and a half. There is no overcharge protection circuit; you will have to control the charging time by eye. The volume is adjusted on the phone or on the player, if someone wants to put a volume control on the speaker, then this can be done without problems, it is enough to send a signal to the right contact of a variable resistor with a resistance of 10-50 KOhm, to the left contact to ground, and connect the central one to the film capacitor at the inlet.

To connect to the player, I used one channel of the cable from the headphones, and the veins from that cable, due to the fact that they are very thin, did not solder directly to the board, but extended them with thinner flexible copper wires and soldered them into the board. I fixed these wiring on the cable with electrical tape. The speaker took a power of 2 W with a resistance of 8 Ohms, wheezing and distortion, except at maximum volume, are not observed. On the player, it is enough to set a maximum of 10 divisions out of 32 to 3, and the volume will be sufficient. You can see a photo of the finished device and a few photos taken at the assembly stage in the article.

To save battery power, I installed a second toggle switch - a power switch. In general, the device of a home-made portable speaker turned out to be simple and any novice radio amateur can repeat it. Author - AKV.

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