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In a high-quality audio system, the main role is played by stereo or multi-channel speaker systems.

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Thanks to them, electrical impulses are converted into sounds in the acoustic range different frequencies. For some, a clean sound that is as close to the original as possible is important. musical instruments, and for some, the voice of the vocalist, film actors or teacher from educational video courses comes first.

How important is the sound system?

It is the basis for the entire audio system.

It is preferable to start selecting a suitable audio system with acoustics.

Moreover, different equipment options will be a priority for each. The choice is influenced by such factors as the “tailoredness” of such a system to those genres that the future owner likes and the price category.

For lovers of the most accurate sound, hi-fi speaker systems are suitable.
Despite the myths, not every expensive audio equipment offers the mentioned capabilities.

When exclusivity comes first, the audio market provides fans of high-quality sound with Hi-End audio equipment.

Reference! High End is a marketing term that refers to the elite quality of software and hardware that enhances sound. Accordingly, the price of such audio systems does not scare only ardent music fans or lovers of non-serial audio equipment who have a good financial condition.

Speaker types

There are several categories of speaker systems, each of which is capable of satisfying specific customer needs. Based on basic differences, there are 5 basic classification groups.

• The principle of equipment installation. Acoustic systems are divided into floor-standing and bookshelf depending on their size. The former are preferable for large premises such as cinemas. Using them at home for a TV or computer is unprofitable. It is best to use bookshelf speakers.
• Number of speakers. Otherwise, this is called division by the number of sound bands. The manufacturer may include from 1 to 7 speakers. The most optimal option for the budget is 3 speakers, where one band is responsible for low frequencies, another for middle frequencies and a third for high frequencies.

• The presence or absence of a sound amplifier in the speakers. In the first case they are called active, in the second - passive. Passive options are much more common. They are preferred by audiophiles due to the crossover filter and, accordingly, higher sound quality due to frequency separation.
• By design, speakers are divided into planar, dynamic, electrostatic and other types, and in some cases the equipment does not fall into any category.
• Design. Speakers can have a closed or open body; a good addition would be a bass inverter - a pipe in the column tuned to certain frequency and amplifying sounds within its boundaries. Thanks to this hole, lower frequencies are reproduced than with conventional equipment. If the pipe is bent inside the body, increasing its length, power and range of reproducible low frequencies, you will get speakers with an acoustic labyrinth. They are more expensive and require greater precision in manufacturing.

Areas of use of acoustic systems

The first and main area of ​​application is home use.

This includes the need for high-quality sound for greater immersion in video games, power and strength of sound for watching TV, clarity and proximity to the original sound for music lovers of various genres.

Fans of high-quality music in the car are recommended to purchase multi-band audio systems.

Moreover, for better sound, high-frequency and mid-frequency elements of the Car system are located in the front of the car. Low-frequency speakers are often assigned to the rear of the car.

Concert versions of acoustic systems are designed not only to provide sound access to any point in a large room or hall, but also to satisfy the sound quality requirements of many listeners. The most common concert audio packages include monitors for nuanced sound, front speakers for high-density direct sound, and center speakers for vocals.

Speakers 1 kW

A separate category is recording studios. They prefer studio monitors that are capable of reproducing sound with all its pros and cons, which ultimately contributes to the creation of a purer and more authentic-sounding track.

Regardless of where the speaker system will be used, it is recommended to first determine the criteria by which suitable equipment will be selected.

With their help, you will be able to get equipment that will bring you as close as possible to the sound of your dreams.

Many people have sometimes had to wonder what exactly the power means, which is given in one form or another in the passports of acoustic systems and sound reinforcement equipment. There are surprisingly few materials on this topic on the Internet and in printed publications, and there are also few clear answers to questions. I'll try to somehow reduce the number of white spots in this area. Some more precise descriptions of definitions arose in my dialogue, while trying to better explain their meaning to my interlocutor.

The variety of standards used to measure amplifier output power and speaker power can be confusing for anyone. Here is a block amplifier from a reputable company with 35 W per channel, and here is a cheap music center with a 1000 W sticker. Such a comparison will clearly cause confusion among a potential buyer. It's time to turn to standards...

Foreign and international standards and definitions

SPL(Sound Pressure Level) - the level of sound pressure developed by the speaker. SPL is the product of the relative sensitivity of the speakers ( speaker system) to the supplied electrical power. It should be borne in mind that hearing is a non-linear instrument, and to estimate subjective loudness, corrections must be made to the weighting curves, which in practice differ not only for different signal levels, but also for each individual.

A-weighting(weighting curve) - weighting curve. A relationship describing sound pressure levels at different frequencies that are perceived by the ear as equally loud. Amplitude-frequency response of a weighting filter used in sound pressure level measurements and taking into account the frequency properties of human hearing.

RMS(Root Mean Squared) - root mean square value of electrical power limited by specified nonlinear distortions. Or in another way - the maximum (limit) sinusoidal power - the power at which an amplifier or speaker can operate for one hour with a real music signal without physical damage. Typically 20 - 25 percent higher than DIN.

Power is measured with a sine wave at 1 kHz when 10% THD is reached. It is calculated as the product of the rms values ​​of voltage and current with an equivalent amount of heat created by direct current.

For a sinusoidal signal, the root mean square value is V2 times less than the amplitude value (x 0.707). In general, this is a virtual quantity; the term “rms”, strictly speaking, can be applied to voltage or current, but not to power. A well-known analogue is the effective value (everyone knows it for the power supply network alternating current- these are the same 220 V for Russia).

I will try to explain why this concept is not very informative for describing sound characteristics. RMS power is the work that produces. That is, it makes sense in electrical engineering. And it does not necessarily refer to a sinusoid. In the case of musical signals, we hear loud sounds better than weak ones. And the hearing organs are affected more by amplitude values, rather than by root mean square ones. That is, volume is not equivalent to power. Therefore, root-mean-square values ​​make sense in an electric meter, but amplitude values ​​make sense in music. An even more populist example is the frequency response. Frequency response dips are less noticeable than peaks. That is, loud sounds are more informative than quiet ones, and the average value will say little.

Thus, the RMS standard was one attempt to describe the electrical parameters of audio equipment as a consumer of electricity.

In amplifiers and acoustics, this parameter also, in fact, has a very limited use - an amplifier that produces 10% distortion not at maximum power (when clipping occurs - limiting the amplitude of the amplified signal with specific dynamic distortions arising), still look. Until maximum distortion power is reached transistor amplifiers, for example, often do not exceed hundredths of a percent, and even higher they increase sharply (emergency mode). Many acoustic systems can already fail if operated for a long time at this level of distortion.

For very cheap equipment, another value is indicated - PMPO, a completely meaningless and not standardized parameter by anyone, which means that our Chinese friends measure it as God pleases. More precisely, in parrots, each in its own way. PMPO values ​​often exceed nominal values ​​by up to a factor of 20.

PMPO(Peak Music Power Output) - peak short-term musical power, a value that means the maximum achievable peak value of the signal, regardless of distortion in general, in a minimum period of time (usually 10 mS, but, in general, not standardized), the power that the speaker speaker can withstand for 1-2 seconds on a low frequency signal (about 200 Hz) without physical damage. Typically 10 - 20 times higher than DIN
As follows from the description, the parameter is even more virtual and meaningless in practical use. I advise you not to take these values ​​seriously and not rely on them. If you happen to buy equipment with power parameters indicated only as PMPO, then the only advice is to listen for yourself and determine whether it suits you or not.

100 W (PMPO) = 2 x 3 W (DIN)

DIN is an abbreviation for Deutsches Institut fur Normung.

German non-governmental organization dedicated to standardization for better integration of the market for goods and services in Germany and the international market. The products of this organization are a variety of standards covering a wide variety of applications, including those related to the field of sound reproduction, which is what interests us here.

DIN 45500, which describes the requirements for high-fidelity sound equipment (aka Hi-Fi - High Fidelity), includes:

• DIN 45500-1 High fidelity audio equipment and systems; minimum performance requirements.
• DIN 45500-10 High fidelity audio equipment and systems; minimum performance requirements for headphones.
• DIN 45500-2 Hi-Fi technics; requirements for tuner equipment.
• DIN 45500-3 Hi-Fi technics; requirements for disk record reproducing equipments.
• DIN 45500-4 High fidelity audio equipment and systems; minimum performance requirements for magnetic recording and reproducing equipment.
• DIN 45500-5 High fidelity audio equipment and systems; minimum performance requirements for microphones.
• DIN 45500-6 High fidelity audio equipment and systems; minimum performance requirements for amplifiers.
• DIN 45500-7 Hi-Fi-technics; requirements for loudspeakers.
• DIN 45500-8 Hi-Fi technics; requirements for sets and systems.

DIN POWER- the value of the power output at the actual load (for the amplifier) ​​or supplied (to the speaker), limited by the specified nonlinear distortions. It is measured by applying a signal with a frequency of 1 kHz to the device input for 10 minutes. Power is measured when it reaches 1% THD (non-linear distortion). There are other types of measurements, for example, DIN MUSIC POWER, which describes the power of the music (noise) signal. Typically, the indicated value of DIN music is higher than that given as DIN. Approximately equivalent to sine wave power - the power at which an amplifier or speaker can be operated for an extended period of time with a pink noise signal without physical damage.

Domestic standards

In Russia, two power parameters are used - nominal and sinusoidal. This is reflected in the names of speaker systems and speaker designations. Moreover, if previously the rated power was mainly used, now more often it is sinusoidal. For example, 35AC speakers were subsequently designated S-90 (nominal power 35 W, sine wave power 90 W)

Rated power (GOST 23262-88) is an artificial value; it leaves freedom of choice to the manufacturer. The designer is free to specify the rated power value that corresponds to the most advantageous value of nonlinear distortion. Typically, the indicated power was adjusted to the GOST requirements for the complexity class with the best combination of measured characteristics. Indicated for both speakers and amplifiers. Sometimes this led to paradoxes - with step-type distortion occurring in class AB amplifiers at low volume levels, the level of distortion could decrease as the output signal power increased to the nominal one. In this way, record rated characteristics were achieved in the amplifier data sheets, with an extremely low level of distortion at a high rated power of the amplifier. Whereas the highest statistical density of a musical signal lies in the amplitude range of 5-15% of the maximum power of the amplifier. This is probably why Russian amplifiers were noticeably inferior in hearing to Western amplifiers, whose optimum distortion could be at medium volume levels, while in the USSR there was a race for a minimum of harmonic and sometimes intermodulation distortion at any cost at one nominal (almost maximum) power level.

Nameplate noise power - electrical power limited exclusively by thermal and mechanical damage (for example: slipping of the voice coil turns from overheating, burnout of conductors at bending or soldering points, breakage of flexible wires, etc.) when pink noise is supplied through the correction circuit for 100 hours.

Sine wave power is the power at which an amplifier or speaker can operate for an extended period of time with a real music signal without physical damage. Usually 2 - 3 times higher than nominal.

Maximum short-term power is the electrical power that the speakers can withstand without damage (checked by the absence of rattling) for a short period of time. Pink noise is used as a test signal. The signal is sent to the speaker for 2 seconds. Tests are carried out 60 times at intervals of 1 minute. This type of power makes it possible to judge the short-term overloads that a loudspeaker can withstand in situations that arise during operation.

Maximum long-term power is the electrical power that the speakers can withstand without damage for 1 minute. The tests are repeated 10 times with an interval of 2 minutes. The test signal is the same.

The maximum long-term power is determined by the violation of the thermal strength of the speakers (sliding of the turns of the voice coil, etc.).

Pink noise (used in these tests) is a group of signals with a random nature and a uniform spectral density of frequency distribution, decreasing with increasing frequency with a drop of 3 dB per octave over the entire measurement range, with the average level depending on frequency in the form 1/f. Pink noise has constant (over time) energy in any part of the frequency band.

White noise is a group of signals with a random nature and a uniform and constant spectral frequency distribution density. White noise has the same energy at any frequency range.

An octave is a musical frequency band whose extreme frequency ratio is 2.

Electrical power - power dissipated by an ohmic equivalent resistance equal in value to the nominal electrical resistance AC, at a voltage equal to the voltage at the AC terminals. That is, at a resistance that emulates a real load under the same conditions.

Don't forget about speaker impedance. Mostly on the market there are speakers with a resistance of 4, 6, 8 ohms, 2 and 16 ohms are less common. The amplifier power will vary when connecting speakers of different impedances. The amplifier's instructions usually indicate what speaker impedance it is designed for, or the power for different speaker impedances. If the amplifier allows operation with speakers of different impedances, then its power increases as the impedance decreases. If you use speakers with an impedance lower than that specified for the amplifier, this may cause it to overheat and fail; if it is higher, then the specified output power will not be achieved. Of course, the volume of the acoustics is affected not only by the output power of the amplifier, but also by the sensitivity of the speakers, but more on that next time. The main thing is not to forget that power is only one of the parameters, and not the most important one for obtaining good sound.

Probably everyone knows common Since ancient times, the expression: “my home is my fortress.” You can, of course, put a variety of meanings into it. But if you look from an everyday point of view, from the position of a caring and economical owner, then this can be perceived as a desire for the greatest possible autonomy, for independence from public utilities with their unpredictable quirks in the form of changes in the conditions for the provision of services, tariff increases, supply failures, preventive maintenance, accidents and the like.

It is no secret that not only the owners of private houses, but also the owners of apartments in high-rise buildings in Lately Increasingly, people are installing their own independent home heating and hot water supply systems. About - in a separate publication, and this article will be devoted to questions of how to choose geyser so as not to have problems providing your household with hot water.

But even before the speech will do about the problems, in fact, of choosing these devices, you need to, at least briefly, familiarize yourself with their basic structure. This is necessary, first of all, in order to try to dispel a number of fairly common prejudices that were formed in the collective consciousness regarding speakers quite a long time ago are firmly entrenched there and are very difficult to “neutralize.”

The design of a geyser and its advantages

In order not to make mistakes when choosing such a heating device, it is necessary to at least approximately understand its structure. Although the range of modern geysers is quite large, their work uses the same principles and internal structure, and functionality.

The diagram shows the approximate structure of a typical modern flow-through gas heater. Of course, specific models from different manufacturers may have their own characteristics, but only in matters of layout or ease of use.

1 – fume hood, closed with metal walls, a volume from which gas combustion products are removed in one way or another. It can be completely sealed or connected to the atmosphere (in conventional, chimney or chimneyless columns).

2 – copper heat exchanger. A pipe system with a “jacket” that receives the direct impact of the flame of gas burners. This is where the heating of running water takes place.

3 – ignition sensor. Provides a control signal to open the common gas solenoid valve only if the ignition wick is operating.

4 – ignition wick. May be different principles actions - this will be discussed below.

5 - gas burner, more precisely, several lines of gas burners, providing their uniform heating of water in the heat exchanger.

6 – water unit, which includes, among other things, a fitting for connecting a cold water main (pos. 9), a screw water flow regulator (pos. 9, not for all models), and a drain valve (pos. 10, also optional, not on all speakers).

Water valve - “frog”

The main element of a water node is always so-called "frog".

In essence, it is a working cylinder, the volume of which is divided into two parts using an elastic membrane.

Both halves of the “frog” are connected to each other by a fitting of a certain diameter. The point is that when water is opened through the column, due to the pressure difference in the two parts of this “frog”, the membrane bends upward and pushes the rod, which is connected to the spring-loaded gas valve, opening it. As soon as the water flow is stopped (the water tap is closed), the pressure under the membrane drops, the valve returns to its original position, and the gas burner, accordingly, immediately goes out.

11 - in this diagram - a unit with microswitches (optional).

12 – gas block with a gas hose connection fitting (pos. 13). This is where the spring-loaded gas valve is located, connected by a rod (rod) to the water unit.

14 – in this column – the electronics unit that controls the operation of the water heater. In inexpensive simple speakers it may simply be absent. Pos. 8 – compartment for batteries (batteries) necessary to generate an ignition pulse on the igniter.

15 – connection connection to the disassembly line hot water.

16 – mechanical regulator that switches operating modes, controls the levels of water flow and gas supply. IN modern speakers can be completely replaced with an electronics unit, with control signals transmitted through push-button or touch control panels.

17 and 18 – cascade of column operation sensors. The specific “filling” may be different - this will be mentioned below in the article.

As already mentioned, any model may have its own distinctive features, but the basic principle of the structure still remains the same.

The diagram for connecting the column to the water supply pipes, regardless of its model, is the same for everyone - it is shown in the figure.

So, when you open the water at the hot water tap, water from the cold main begins to flow through the column. The pressure of the water flow opens the gas supply valve, which causes the burners to ignite (more on the ignition mechanism below). The energy of the combustion gas is converted into heating water - and water flows at the required temperature from the “hot” taps on the mixers.

This is one of the main advantages of a geyser - it works exclusively at the moment when hot water is required, the rest of the time being in “standby mode” or in the off state. The owners of the house (apartment) use hot water only when needed, and at the same time do not depend on work in any way.

The second main advantage is, of course, operating costs. So far, at a cost of natural gas no other energy carriers can compare.

The speaker, of course, also has disadvantages, and considerable ones.

• It will not be possible to install it on your own - coordination with the relevant organizations, drawing up and approval of projects is required (unless, of course, the house was previously equipped with such water heaters).
• The operation of a water heater, even in its most modern version, still requires all residents to comply with certain safety rules.
• A stock of heated water is not created, unlike an electric or gas boiler.
• The initial installation of the column may involve very large-scale work to ensure the removal of combustion products or to create forced ventilation.

It should be noted that the designers of geysers managed to solve most of the “old problems” of gas water heaters. instantaneous water heaters. Nevertheless, a certain number of people still have some kind of bias towards them. Therefore, in the next section of the article we will try to take a closer look at modern ones precisely in the light of persistent myths about their danger or inconvenience.

Video: general structure of a typical gas water heater

Modern geysers – should we be afraid?

An interesting feature of geysers is that, willingly or unwillingly, they can even change demand, and therefore prices, in the secondary housing market. Realtors won’t let you lie - very often one of the main issues during the initial consideration of proposals is connecting the house to a centralized hot water supply and, accordingly, the presence or absence of gas water heating systems.

It is characteristic that there is no unity of views on this issue. Of course, people, exhausted since childhood by the old Soviet ones, with their whims, noise, unsightly appearance, with constant “pressure” from elders about strict rules of use and the danger of violating them, they don’t want to hear about purchasing an apartment with gas water heaters.

However, there is also the opposite category - people who are already familiar with the fickleness of public utilities, with inflated tariffs and payment by meters for hot water (moreover, in order to wait for the first drops of hot water, it is often necessary to pour at least 3 ÷ 5 minutes of cold water, since the circuits circulation in many multi-storey houses are simply cut off). And such experienced clients, on the contrary, will be more satisfied with housing with a speaker. However, many people prefer to combine both possibilities - this is the most reasonable approach.

What are the main “myths” about geysers that continue to live, scaring away potential buyers of such equipment?

1. The column is very difficult to operate; it requires independent ignition with matches and constant monitoring.

Let's figure it out.

Well, firstly, any technique requires control, regardless of complexity. No one blames the gas stove for this open flame, or a faucet in the bathroom, which also needs to be monitored so that it does not leak over time.

Secondly, lighting with matches can only be found on those very “rarities” of the Soviet installation. Perhaps they are still produced somewhere, however, all, without exception, modern models worthy of mention are fired up differently.

— The simplest, “imperfect” modern speakers are equipped with piezo ignition. Before use, it is necessary to light the igniter wick by pressing the corresponding button, while turning the control handle to the appropriate position. Even this scheme is considered “outdated”, is used less and less and is giving way to other principles of ignition.

— Electric ignition is popular. At the moment the water starts, a sensor is triggered, which gives a signal to the electric igniter. At the same time, a channel for limited gas supply to the torch opens and a spark is generated to ignite it. The energy for sparking comes either from installed batteries (usually 1.5 or 3 volts) or from the power supply.

- One more modern method is the "HidroPower" system. In the supply pipe cold water a hydraulic turbine is built into the column. At a certain liquid pressure (usually about 0.3 - 0. 5 bar) the turbine induces an electrical charge sufficient to produce a spark for ignition of the igniter torch, which then it will transfer the fire to a common gas burner.

All this takes a long time to read - but in fact, the process of automatically igniting the flame when water is turned on occurs within just a few seconds.

So, in modern water heaters, no special human intervention is required (except for first opening the gas tap): turn on the hot water and use it.

By the way, you can immediately give an answer to a possible problem - why do you need an ignition burner (torch) at all? Surely it’s impossible to immediately ignite the main one?

It is forbidden! Until the torch warms up the sensor, the gas start solenoid valve will not operate. The very small amount that is taken at the moment of starting on the wick does not pose any danger to people - it will easily escape into the ventilation. But if suddenly the column accidentally goes out, the sensor has cooled down, then the gas supply will be blocked - the solenoid valve will close the line completely.

2. It is a very common belief that the column is a very explosive device.

What could explode there? If we are talking about gas, then it is no more dangerous in this regard than a regular gas stove. In the same way, provided that there is no leak, ventilation is normal, there is no place for an explosive concentration of gas to come from.

If we talk about the likelihood of an explosion of an overheated volume of water, then a boiler in this regard is probably even more dangerous. In the column, with its flow principle of operation, there are much fewer such conditions for an explosion. Moreover, in any (even the oldest and most imperfect) there are always at least two lines of “defense”, about which at same mentioned: an electromagnetic valve, which will not allow the burner to ignite independently, and a “frog” water valve, which shuts off the gas in the absence of water flow.

3. The fear is somewhat similar to the second point: there may not be an explosion, but a gas leak will lead to poisoning and a sad outcome.

You can refute it by citing all the same arguments that were presented two paragraphs above. And we can only add once again: the degrees of protection of a conventional gas stove- much less, and the likelihood of a gas leak from the stove or oven into the living quarters is much higher. Nevertheless, for some reason, they are more afraid of gas water heaters in this regard, although this is completely illogical.

4. Another very persistent, but completely incomprehensible prejudice is that a gas water heater will completely ruin the interior of the kitchen.

Probably, only someone who can’t get the image of an old, rust-covered ancient pump with metal pipes leading to it in his imagination, can say this only.

Blaming modern geysers for being unsightly is the same as making similar complaints about refrigerators, microwaves, hoods, ovens, etc. Gas water heaters They fit perfectly into the kitchen decor, take up very little space, and sometimes stand out against the general interior background just by the presence of a chimney. (and even then - not always).

Prices for the range of heating boilers

Heating boilers

What Another thing to consider when choosing a column

So, we come to a common opinion: there is no need to be afraid of geysers, they should become reliable and safe helpers in the household. This means that we should take a closer look at the criteria that should be taken into account when choosing this device in a store.

Gas water heater power

Under this parameter lies the ability of the geyser to heat a certain amount of water per unit of time to the required temperature. In general, the entire variety of these devices can be divided into three classes:

Gas water heaters low power. The rating does not exceed 19 kW, and such a water heater is capable of serving only one point of consumption at a time.

Medium power speakers include devices rated from 20 to 28 kW. Usually they are already enough to simultaneously draw heated water in two places.

The most powerful are geysers that produce 29 kW or more. Their performance is even enough to take a bath in one place with simultaneous, for example, washing dishes in the kitchen, or with simultaneous using hot water in three places is quite enough for any “everyday” situation, even in a large country mansion.

It may be objected that kilowatts, although they are indicated in the product passport and on the information plate on the case, still mean little to the average user. It’s difficult to argue with this, so we’ll try to explain this meaning more clearly.

The main purpose of the column is to raise the water temperature from the initial value ( TVx) to what is required for household use (TN). The difference between these two values ​​(delta) will show what our water heater is capable of.

ΔТ = Тн - Твх

The “delta” itself is not interesting - you need to know how much water the column can heat for such a difference per unit of time. (usually measured in liters per minute).

How to determine the required power?

It can be taken as a statement that for the normal functioning of a kitchen sink, about 4 liters of heated water per minute are required. For taking a shower, 6 liters is usually enough. (These values ​​have been tested in practice, and, by the way, they are what are used to guide the development of special economizer devices in the form of aerators or special fittings, which, even if desired, do not allow the use of larger volumes, thereby helping to save water).

The power of the required water heater can be calculated using the formula:

M = ΔT × Σv/14.3

M – required power,

ΔT– heating value (see above)

Σ v– total volume of simultaneous consumption;

14,3 – coefficient taking into account the heat capacity of water.

Let's assume that a column is selected that allows simultaneous use of a shower and sink in the kitchen. The total volume will be Σ v= 4 + 6 = 10 l/min.

Magnitude ΔT– depends, of course, on the inlet water temperature. If we assume that water comes from a water supply with a temperature of about 10 - 15 ° WITH, then a rise of 25 degrees should be quite acceptable - the output will be about 40 ° WITH, which is enough for both taking a shower and washing dishes.

In total we get:

M = 25 × 10 / 14.3 = 17.4 kW

It is clear that this value is the lower permissible limit. It is recommended to add another 15 - 20% reserve to it, and then round up to whole numbers. We get 21 kW. The speaker you purchase must have this power. Of course, all models of water heaters have their own gradations and capacities, but you need to buy one so that the value is not lower.

Perhaps this may seem too complicated. In addition, the initial temperature value may be different, for example, in winter time the water may have about 5 degrees at the inlet. In order not to force readers to “suffer” with formulas, it is better to provide a table in which the power of the column will be linked to the inlet temperature and the overall performance of the device, provided that it supplies water to the mixer at 40 ° WITH:

Usually both power and ΔT are the basic values ​​of the water heater and must be indicated in the technical documentation.

And the most accurate calculation using the same formula will be possible with the proposed online calculator.

Using it is not difficult.

• First, the temperature that is planned to be obtained at the output of their column is indicated. At the discretion of the future owner - for some, 40 degrees is enough, but maybe someone wants it cooler or, conversely, hotter.
• The next step is to indicate the temperature of the water supplied to the column. Here you can proceed either from existing circumstances. For example, from some sources - wells, boreholes, storage tanks, water is supplied, regardless of the time of year, always at approximately the same temperature. And you can calculate for the most unfavorable conditions, when the water is so cold in winter that it is close to the freezing line.
• Next, you need to indicate (check the boxes) those hot water collection points that, according to the owners, can be used simultaneously without interfering with one another. Of course, if you supply water to all plumbing fixtures at once, then you probably won’t find such a powerful device.

But this is all decided at home, so to speak, by administrative methods. And it’s difficult to imagine a situation where one family member, for example, is washing dishes in the kitchen, while a second one is standing in the shower stall, a third one is taking a bath, etc. And the calculator, by the way, will help you fully imagine what can be used at the same time.

• All other values ​​- the average statistical consumption at points of consumption and the heat capacity of water - have already been entered into the calculation program.
• All that remains is to press the “CALCULATE…” button - and the answer will be given, expressed in kilowatts of the required thermal power of the column. In addition to the calculated value, another one will be shown - taking into account the 15% power reserve, since “driving” the water heater to the limit of its operating capabilities is far from the best solution.

Greetings to all readers! Anyone who has ever chosen a speaker system has thought about the power of the speakers in watts - what this parameter is and how it affects the volume of the equipment.

Today I will tell you how sound in speakers is measured, what volume depends on, and how to find out sufficient parameters for a room of a certain size.

Effect of total output power on volume

Oddly enough, the high power of the equipment does not always mean that it will play loudly and “meaty”. When choosing speakers for your computer, you should remember that watts, roughly speaking, is the amount of energy consumed by the equipment.

Depending on the efficiency of the system (and it can sometimes be extremely low), the final volume can be significantly adjusted.

Sound volume is a subjective characteristic. It is measured by intensity, which is proportional to the square of the sound pressure amplitude. It is affected by the sensitivity of the human ear.

Different people may perceive the same frequency ranges differently. In addition, sensitivity decreases with age.

Total power output is not the only parameter that affects sound pressure. The volume of the system as a whole also depends on the sensitivity of the speakers and the power of the amplifier.

The lower the sensitivity of the speaker, the more powerful the amplifier will be required to activate it.

Measuring systems

Despite the above, the most effective tool for marketers when selling PC speakers remains power, expressed in watts.
Until recently, about 20 years ago, only old acoustics produced by Soviet industry and Chinese equipment, which was beginning to capture world markets, were available on the market.

High-quality European and American electronics were simply not supplied to us due to the sky-high cost, inaccessible to the vast majority of customers.

The passport of Soviet, and subsequently Russian electronics, indicated the rated power, which continues to be considered one of the most objective parameters. This characteristic is determined at the middle position of the volume control.

The Chinese have traditionally indicated PMPO - the maximum power that a speaker can theoretically withstand without mechanical damage, and the amplifier can “pass” through itself without burning out or melting the filling.

It was not uncommon to see a proud 500 Watt sticker on a miniature speaker. Naturally, not a single such system was equipped with a power supply capable of accumulating such an amount of energy.

This calculation system was called “Chinese watts”. According to the results of numerous tests, this figure was 20–30 times higher than the rated power. On this moment, fortunately, PMPO is almost never used, and the characteristics of Chinese electronics indicate the rated power.

This is understandable: apart from China and some other Asian countries, almost no one produces equipment today. It no longer makes sense to fight for the market with the help of such cunning manipulations - it has long been captured and monopolized.

Other standards

In this topic it is impossible not to mention the DIN 45500 standard, which first classified the concept of Hi-Fi equipment.
According to accepted standards, DIN Power is measured here by applying a signal with a frequency of 1 kHz to the linear input for 10 minutes.

When 1% THD is reached, power is measured. This system is completely identical to the Japanese EIAJ. DIN Music Power is another parameter, the maximum signal that the equipment will withstand without damage for a long time.

This indicator meets IEC Power, according to the International Electrotechnical Committee standard IEC 268–5. The duration of the load is 100 hours.

RMS is the maximum sinusoidal power, that is, the one with which the device can operate for an hour without damage. Typically this value is 150–200% more than the Soviet rated power and 20–25% more than DIN Music Power. AES2-1984 is close to this standard, according to which measurements are taken over a two-hour period.

How to determine the appropriate power

So, we come to the main question: the total power of the speakers - what is it and how does it affect the sound quality. Total power – the sum of the powers of the subwoofer and satellites in the speaker system. For what area of ​​the room which acoustics are best suited can be determined according to the following principle:

• For an office and other workplace - no more than 20 Watts, so as not to disturb colleagues;
• For the room standard size– from 20 to 50 Watt;
• For a living room, home theater or game room - from 50 to 150 watts.

It makes no sense to take more powerful speakers - anyway, you won’t be able to use them “to their fullest” without disturbing your neighbors in the house. If you live in the private sector and prefer very loud music, you can take at least 300 Watt speakers, put them outside and delight the residents of the neighborhood with your musical preferences.

And this is a purely subjective characteristic, therefore, even when buying sophisticated speakers from a world-famous brand, do not be lazy to conduct a test listening - in case you don’t like the frequency range.

About the main parameters and technical characteristics of speakers for PC. Also on this topic, I advise you to read audio speakers for PC and pro and development acoustic speakers. I would be grateful if you share this post on in social networks. Till tomorrow!