Car subwoofer scheme. Sabwofer do it yourself: how to make, theory, schemes. What are the box for a subwoofer

How to make an active subwoofer

As a passive subwoofer make an active, often ask newcomers interested in improving automotive acoustics. If you know the difference between these types of dynamics, the process of alteration will not be difficult.
The complexity of the process of how to make a passive subwoofer is active, lies in the fact that you need to be able to determine the difference in the sound and produce the right calculations.

The concept of subwoofer

The newcomer will be useful will know why this speaker is generally intended. Is it easy to use a couple of multi-voiced speakers and calmly enjoy full-fledged sound? It turns out no.

Note. As you know, the subwoofer is designed to play low frequencies that have low localization. If there were no one speaker enclosed in a separate building, it would be difficult to determine which point is the sound. It will seem not real, too voluminous and enveloping.

In addition, if earlier, when the subwoofer was not invented (see), speakers for playback different frequenciesIncluding low, should have been enormous and expensive, then with the advent of a separate Saba, everything was much simplified, both in terms of volume and cost.

Difference

So, the subwoofers are designed to play low frequencies. It's clear. But why are there passive and active species? What is the difference? Let's try to figure out.

Passive

This Sab in its design is a low-frequency enclosed in a separate building. To achieve the desired sound from it, you will have to connect it to two separate elements: External amplifier and crossover (see).
The latter is nothing but a separation filter that distributes frequencies and guiding them on the speakers.

Active

This type of subwoofer already has a built-in amplifier in its design. Also built inside it and crossover. It eliminates the user from the complex connection process and the setting of the speaker is also quite simple.

Note. Note that due to the presence of its own amplifier, the active SAB must be connected separately to the power.

Some users not to overpay for an active subwoofer, are decided to make it themselves from passive. The idea is interesting and fully justified yourself in practice.

Note. The alteration of the passive subwoofer into active involves connecting to the power amplifier and the crossover, which must be embedded in the speaker. Only this setting this requires specific knowledge.

Calculation of indicators

If we did an active subwoofer completely from scratch, then first of all, it would be necessary to download from the Internet or find the program to calculate acoustic decorations in another way.

Note. For example, it may be Ji Bie El Speaker, which includes two more independent graphic schemesI need to determine the required volume and size of the COPUS, as well as allowing you to choose two directions for the body.

In addition, it would be necessary to find famous values Tila-Small. They are needed, by the way, in our case.

The fact is that the emitters mounted in the dynamics may not comply with the above parameters. And then you have to measure it again.

Measure

Started:

  • First, the resonant frequency FS is measured. This parameter indicates the frequency without any additional design.
    FS is calculated so: the emitter is suspended in the air on a large distance from foreign objects so that external characteristics do not affect this value;
  • It is better to measure the resonant frequency in a free garage or another room. Speakers hang on the ceiling;
  • Open the program tone the generator on the computer;
  • The initial frequency is made at 10Hz, and then the frequency increases in a step in 1Hz. At the same time, it is necessary to look at the testimony of a voltmeter. Thanks to the graph below, you can determine the desired value;
  • The approximate frequency of the dynamics of FS in step 1Hz will be maximum value voltmeter;
  • To calculate the exact value, you will need to change the frequency no longer per 1Hz, but by five hundredths of it.

Note. Some believe that a strongly low resonant frequency is ideal for a subwoofer. This is so, but partly, because for some designs, such a low resonance can lead to interference.

Second meaning

  • Then the complete electromechanical QTS electromechanical quality is measured. Interestingly, Quality has two indicators: mechanical and electric.
    The first is determined by the choice of suspension material. Quality is often measured by the handicraft method: swaying. Low conditionality of the subwoofer is 0.3 / 0.35, and high - 0.5 / 0.6.
  • Electromechanical quality is found according to the formula where the values \u200b\u200bwill perform two components, one of which is lower than the resonant frequency, and the other above.

Equivalent volume

Finally, the third value that we need to calculate is the equivalent volume of VAC:

  • To determine such a volume, the phase reserver is needed with a hole. From the manufacturer, the volume of such a box in comparison with the diameter of the speaker has already been agreed. Therefore, nothing needs to do anything;
  • Again, according to the program, the generator is determined, as in the case of a resonant frequency. Only calculations are carried out according to the following formula:

Alteration of housing

In order to get high-quality sound, some computations are not enough. It is necessary to carefully prepare the case of the subwoofer, altering it under the active version.
What did we achieve computing? Determined the inner volume of the drawer, the length and diameter of the phase internal.

Note. It is believed to remake passive subwoofer In the active much difficult, than to do everything back with your own hands. Thus, a homemade box is made with the desired holes.

One thing is necessary: \u200b\u200ban active subwoofer (its body) should consist of 2 compartments. The emitter or loudspeaker is in one of the compartments, and the amplifier, crossover and power supply in the other.

Note. From the inside to the walls of the compartment, where the amplifier will be, the power supply and the separation filter will be recommended, it is recommended to glue foil. It eliminates the negative effects of external fields and minimizes the noise level.

  • After that, only how the signal was formed, it enters the amplifier, and then into the emitter.

So, we found out that the alteration can be carried out with their own hands. IN this case It will be extremely useful to watch a video overview on the topic or the corresponding photos - materials.
It is necessary to act strictly according to the instructions. Thus, if everything succeeds, we will not sleep well, because the price of the active subwoofer is quite high.

Subwoofer do it yourself

Sooner or later, many understand that the bass does not happen much, and no matter how much the columns are more powerful - the bottoms still want more. Output one - use subwoofer. You can buy a good subwoofer, but the extra 200 - 300 $ will be far from everyone. So we will do a subwoofer with your own hands!

At first, I will solve the issue with nutrition: a good transformer, Watt on 150 having the necessary two-polar stress and the current on the road is not lying on, but I really don't want to wind yourself. Do not need. We buy an electronic transformer to the standard voltage 12 V and the power of 100 - 150 watts and connecting the ferrite ring K40X30X20 to its output with the primary winding of 13 turns of Pal 1.2; Two secondary on 28 turns of the same wire we have a two-polar stress of 25 V.

Scheme subwoofer do it yourselfconsists of an active filter on TL082 (TL062) and the most amplifier collected by standard two-stroke scheme. To improve the quality of sound (and who said that bass is not critical to the distortion factor?), There is a couple at the output field transistors. In more detail about the FNF - calculation, scheme and drawings printed circuit board . One of excellent options Filter diagrams for a subwoofer with a phasemator - in the picture.

Feeds a subwoofer or from the aboveelectronic transformer, or from the usual on the transformer, with two windings of 20 - 30 V for current 3 A.

Should consider thatelectronic transformers do not work at low load currents, so thissubwoofer do it yourselfit works in the class, but what do you understand also very well reflected on the quality of sound. The current consumption of each shoulder should be at least 0.6 A. It is displayed by a stroke resistor for 1 to.

Alternatively, you can quality umzch Use the TDA7294 chip included in the diagram below.

Speaker for subwoofer do it yourself We take any low-frequency than more powerful - this sub produces more than 100 watts of pure sinus. Power + -30 B, with a maximum current consumption in peaks, up to 4 A. The measured harmonic coefficient is less than 0.1%.

For housing Subwoofer do it yourself We use the old Soviet wooden TV, you can tube or 3UST.

From above in the center we cut, and we get two sides with halves of the top. That is, two letters of G. One of them turn - the frame is ready, and the bottom will be used as a rear wall. Shakes to legitimize sealant and do not forget to do the front hole of the phase inverter with a diameter of 8 mm.Read more about the calculation and manufacture of the case can be viewed on other resources. And here are read practical detailed example of assembly

Interesting ways to do, quite a lot. And sometimes homemade subwoofer even gets much better than purchased, if, of course, do everything right.

What can a subwoofer make?

Something similar to a subwoofer can be built from several pieces of plywood and old speakers. And in general, as for the column of the subwoofer, it is possible to buy it, for example, on a radio station.

Enjoy clear and in the car it is possible and by using the subwoofer of an inactive plan. In addition, it will not make any special work on their own. It will not require the installation of the amplifier, and the work will be reduced only to the design and assembly. As for the installation of such a subwoofer, it is right into the box.

Video on how to draw a subwoofer hull:

Start the manufacture

The first thing to do is armonize required materials and tools. For the manufacture of home production subwoof, we will need:

  • speaker;
  • lattice protective;
  • good glue, better epoxy;
  • a socket through which connection will be carried out;
  • fiberglass;
  • wire, 3 mm;
  • brush;
  • plywood;
  • Chipboard, 16 mm;
  • nuts and screws, be sure to wood;
  • bolts;
  • malyary Scotch;
  • polyethylene;
  • universal putty.

And of course, the tools - where so without them:

  • lobzik on a tree;
  • sculpture or drill.

Begin. First you need to pick up a good speaker. It is not worth saying that the more powerful it will be, the louder will be the sound. How to get it? It is worth noting that the speaker can get to you in the hands of different ways. The main thing is to have data on its technical indicators. After all, the design of the hull will depend on them, and this is very important.

So. As for the indicators, it is necessary first of all to obtain data on the frequency of the resonance of the dynamics, which you have turned out to be in the open space. In addition, it is also necessary to know the data on the equivalent volume. If there is no such data, it is better to go and buy a speaker in the store, where it will be supplied with special documents. You can choose the speaker modest or expensive. Here everything will depend only on you.

Now the second stage, called the design of the subwoofer box. You can use the special computer program WinLSD 0.44. This utility will actually help. It is she who will need to make these dynamics, its parameters. And the computer program of this type allows you to make a box of four species. We will look at the box that has the highest efficiency. In other words, Bandpass 6th level.

The sixth level bandpass is a rectangular cubic object within which there is one jumper. It is on it that our speaker will be recorded. In addition, such a bandpassa has two holes that are intended for mounting phase inverter cameras. Instead of cameras, you can use various tubes. For example, it may be tubes from polyethylene, metal or just paper. It is worth noting that the case must be completely sealed and this can be done with the help of felt, foam rubber or ordinary wool.

As for the sealant layer, then inside it should have two centimeters. And the roof of the subwoofer must be removed and have a high density at the junction. Therefore, it is also additionally enhanced by a layer of foam rubber.

Computer utility will help all sizes. It will calculate the optimal numbers for the housing, of course, based on the possibilities of the dynamics. The task of man becomes in this case only everything is clearly and competently embodied in reality. And the sound, of course, will justify all expectations. It will work clean and loud.

It is believed that in general, collecting a subwoofer is a challenge difficult, if not to be extremely attentive to various kinds of small things and nuances. A person collecting homemade subwoofer should not only understand the acoustics, but also to have the ability of a carcass on a tree, be able to screw the screws and bolts, as well as working with sealant. For a homemade craftsman is a kind of challenge.

Place for subwoofer

Now about where we install our subwoofer. Choose a place for it. The best will install it in the wing: the right or left, we decide. Although it is worth noting that the places will be more in the right wing, due to the features of the configuration of many cars.

If we chose the average speaker, then it for normal work It will take a minimum of 28 liters of volume. As for the configuration and volume of the box itself, it will have to experiment. Typically, the volume is obtained big, but it is not scary.

The trunk is plated by plastic film, after which we glue with a painting stitching, be sure to two layers. Take fiberglass and cut it with pieces. In this case, they should get 200 × 200. We definitely lubricate them with epoxy glue and put on the tape flashes.

Now about how to breed epoxy glue. It will be right to do this: the jar of resin and the bank of the hardener mix. If you take any of these substances more than the norm, the glue will quickly thick and you will not have time to use it. The perfect ratio is 1: 1.

The back wall of the self-made subwoofer, or saba, we glue with three or even four layers of fiberglass. Then we wait until everything is dry. It is better to time.

The next day you will need to remove the resulting shell. Its thickness is already increasing outside the trunk. We start incuring the bottom of the subwoofer. His top is done in the form of a loop, and the front wall is fastened with a self-tapping screw. As for the joints, they will need to be missed with epoxy glue.

Thin work

After the cabinet is ready, you need to prepare it under the acoustic terminal, then you mean the speaker. To do this, you need to open a hole on one of its side walls. You can make it an ordinary school cycling.

Powerful are obtained if it is shielded by a small box. These are no longer an ice-made design of subwoofers, and the present art. Thus, we will be able to eliminate the various ghosts that will arise due to a sufficiently slop acoustic terminal.

A box may have a square shape. It is processed by PVA glue and screw to the sidewall, where the hole was cut, with the help of self-tapping screws.

Now you need to take the branches and cut off all the protruding edges of the case. When it was above the special skills, it was not reasonable. And here you need to have the skill of a carpenter, so that it will cope with the work on five with a plus.

Go ahead. We take a jigsaw, preferably electric to work more convenient, and cut the hole in the front panel. It will need a speaker there, fleeing there on self-drawing and glue. If I remembers the reader, inside our box, or the sixth level bandpassis, there is a jumper. Here and you need to cut.

Protection measures

Everything seems to be ready, and the amateur will immediately hurry to connect. But to rush to the master to anything, every step in work for him is the opportunity to touch the sublime art. So, in this case, do not forget about the protection of self-made creation from moisture and condensate. Another medieval person was known that moisture on the tree, and in this case the subtle chipboard acts destructively.

To secure in advance and protect the body, you need to soak it with a special furniture nitrolom. This procedure is desirable to carry out in the fresh air, in order to avoid lacquer poisoning.

Soaking Do not forget the inner end of the front panel.

Video demonstrating independent manufacture Subwoofer:

Well, it seems to be everything. It's time to explore the subwoofer schemes and connect. Although for a more spectacular finish, it is useful to see our subwoofer with some material for beauty. If you have a carpet, then it can be the material.

In this article, we will see how to make a subwoofer with your own hands, not delighted in the depths of the electroacoustics, without resorting to complex calculations and subtle dimensions, although some should still have to do. "Without special difficulties" does not mean "Trep-Lump on the brick, drive, grandmother, Mogarych." Nowadays on home computer You can simulate very complex acustic systems (AC); Link to the description of this process, see at the end. But work with the finished device on the Nativity gives anything that you will not get any reading and watching - an intuitive understanding of the essence of the process. In the science and technology of opening at the tip of the pen rarely are committed; Most often, the researcher, by taking experience, the "chute" begins to understand what is there to what, and then looking for a mathematics suitable for describing the phenomenon and the withdrawal of settlement engineering formulas. Many great with humor and pleasure recalled their first unsuccessful experiences. Alexander Bell, for example, the coils for his first phone tried at first to wind with a naked wire: he, a musician for education, simply did not know that the wire under the current you need to isolate. But the phone Bell still invented.

About computer calculations

Do not think that JBL Speakershop or other acoustics calculation program will give you the only possible most correct option. Computer programs They are written along well-established proven algorithms, but nontrivial solutions are not possible only in theology. "Everyone knows that it is impossible to do so. There is a boyfriend that does not know that. Oh, and makes the invention " - Thomas Alva Edison.

Speakershop appeared not so long ago, this app was developed very thoroughly and the fact that they enjoy very actively, unconditional plus both developers and lovers. But something in the present situation with it looks like a story with the first photoshop. Who yuzal is still Windows 3.11, remember? - Then on the processing of pictures just went crazy. And then it turned out - to make a good picture, you still need to be able to photograph.

What is it and why?

Subwoofer (simply - sab) in the literal translation sounds beside: Podkavka. Really, it is a bass (low-frequency, LF) speaker, reproducing frequencies below approx. 150 Hz, in a special acoustic design, a drawer (box) is a sufficiently complex device. Subwoofers are used in everyday life, in floor high-class speakers and inexpensive desktops, built-in and in cars, see fig. If it turns out to make a subwoofer, correctly reproducing bass, you can safely be taken for, because Playing the LC, perhaps the most fat from whales, on which all the electroacocci is worth.

The compact NCH-link AC make a lot more difficult than the sch and HF (medium and high-frequency) first, due to acoustic short circuitWhen the sound waves from the frontal and rear radiating surfaces of the dynamics (loudspeaker heads, GG) are quenched by each other: the wavelengths of the LC - meters, and without proper acoustic design of the GG, nothing bothers them immediately in antiphase. Secondly, the spectrum of the sound distortion on the LC stretches away in the best of all the hearing area of \u200b\u200bthe sch. In essence, any broadband AC is the LF-link, which is built into the SC and RF emitters. But an additional requirement is presented to Sabu from the point of view of ergonomics: the subwoofer for the house should be as compact as possible.

Note: All types of acoustic design of the LF GG can be divided into 2 large classes - one quench radiation from the rear of the dynamics, the second turn over the phase by 180 degrees (turn the phase) and re-energized from the front. Subwoofer, depending on the properties of the GG (see below) and the desired view of its amplitude-frequency response (HCH) can be built according to a scheme of a particular class.

The direction on the sounds below 150 Hz people distinguishes very badly, so in the usual residential room, the SAB can be delivered in general anywhere. SC-RF AC (Satellites) Acoustics with a subwoofer are obtained very compact; Their location in the room is possible to choose optimal for this room. Modern housing with an excess square and good self-acoustics, to put it mildly, is not different, and "trinked" in it correctly at least a couple of good broadband columns is not always possible. Therefore, the manufacture of a subwoofer independently allows not only to save a very solid amount of money, but also to get a clean, faithful sound in this Khrushchev, Brezhnev or modern new building. Especially effective subwoofer in high-clock sound systems, because Put 5-7 columns on the full band Each is too too much and for the most "tricky" users.

Basy

Basic playback is difficult not only technically. Nearby in the general LF region of the entire spectrum of sound waves is heterogeneous in its psychophysiological influence and is divided into 3 areas. To properly choose a bass speaker and make a box for a subwoofer with your own hands, you need to know their borders and meanings:

  • Upper bass (Upperbass) - 80- (150 ... 200) Hz.
  • Middle bass or Midbas (Midbass) - 40-80 Hz.
  • Deep bass or subhead (subbass) - below 40 Hz.

Verkh

Middle

On Midbas the main task When creating a subwoofer - to provide in the minimum volume of the box the highest return of the GG, the specified Form Ahh and its maximum uniformity (smoothness). Ahh, to the side lower frequency Close to rectangular, gives a powerful, but harsh bass; Ahh, evenly falling - clean and transparent, but weaker. The choice of one or another depends on the nature of the listened: rockers need a sound "evil", and more tender for the classics. In the matter ofwards, large failures and bursts on the response spoil the subjective perception at formally identical techniques of sound.

Depth

The subbas is determining the influence on the timbre (color) of the sound of musical instruments only for wind bodies in specially built by the halls. Strong sub-test components are characteristic of the sounds of natural and technogenic cataclysms, strong explosions and voices separate species Animals (Lion River). Over 90% of people subbasy or not hear at all, or hear vigorously. For example, if the sounds of tropical hurricane and nuclear explosion are fundamentally different in their nature from everything, except for subabasses, it is unlikely that anyone will figure out that there is actually going on. therefore domestic subwoofer Almost always optimize on Midbas, and the rest of the subbasa, what will happen, disguises its own room noises. For what he, by the way, is very suitable and what is very useful.

Subbas in the car

The effect of disguise the noise is especially necessary in the close and cozy salon of the car, so the automatic cluthers are optimized on the subbas. Sometimes for this, Hi-Fi lovers at speed give the entire trunk, setting there 15 "-18" monsters speakers at 150-250 W peak power, see fig. However, a completely decent subwoofer in the car can be made and without sacrificing a useful volume in the body, see below.

Note: The peak power of the dynamics is often identified with noise, which is incorrect. At peak power, the sound is distorted, but it is still impaired, i.e. We distinguish in meaning. Noise power is defined as such on which the speaker can work a certain time (usually 20 minutes), not burning and not damaging mechanically. The sound at the same time is most often incoherent wheezing, which is why such power and called noise. But in some types of acoustic registration, the noise power of the dynamics may be below the peak, see below.

What is the speaker?

The full calculation of acoustic design is made by T. Naz. Tila-resin (TCP) parameters. Since we decided to spend time and work on the configuration of Saba, we need only the complete quality of the head on its own resonant frequency of QTS, because It is for it that optimal option acoustic design. Depending on the QTS values, the speakers are divided into 4 groups:

  • QTS.<0,5 – «безразличные» сверхнизкодобротные. Очень дорогие, очень низкая отдача, но способны воспроизводить подбасы вплоть до 20-15 Гц. Настройка сабвуфера с такими без звукомерной камеры и специальной измерительной техники невозможна, т.к. резонансный пик не выражен.
  • 0,5
  • 0,7
  • QTS\u003e 1 - highly relevant. High return, low price, hard sound in non-optimal design. It is difficult to get a smooth response. Compact, produced with a diameter (at a smaller side) to 6 "(155 mm). Optimal for the subwoofer of the desktop or TV (not to the home theater!).

Measurements

In the manufacturer's specifications on the QTS speakers, it can be designated as quantity or simply q, but it is not always present, and in publicly available databases like WinISd is full of errors. Therefore, we will most likely have to determine the value of QTS at home.

Preparation

First of all, we choose and prepare for acoustic measurements of the room. It should be as many curtains, curtains, curtains, carpets on the floor and walls, upholstered furniture. Hard horizontal surfaces (table) need to be covered with something fluffy; It will not be superfluous and to paint everywhere more pillows. Especially distorting the sound field of the corners, incl. Rigid furniture with walls, they need to curtain something, for example, clothes on her shoulders. Next, connect the long wires to the dynamics and hang in the geometric center of the ceiling (under the chain, if it is) the front side of the diffuser down at the height from the floor in 2/3 of the ceiling height.

Now you need to assemble the measurement scheme, as shown at the top in Fig. The lower scheme will still be needed to measure the impedance (impedance) of the dynamics of Z. From usually used by the measurement circuit with the measuring circuit without a transformer, this is distinguished by quite professional accuracy: in the commander the schemes on the diodes of the bridge is lost approx. 1.5 V, even with the input resistance of the tester of 10 MΩ. The action of this scheme is based on the fact that the impedance of the transformer and R2, on the one hand, much more impedance of the GG; On the other hand, there is a lot of less than the output resistance of the sound frequency power amplifier, and on the fact that the fastest digital multi-meltter at the limit 200 mV has an input resistance of more than 1 mΩ. However, if the measuring signal is supplied from the sound frequency generator (GZH) with a standard 600-ohm output, this scheme for measuring Z is unsuitable.

Procedure

From a computer with a GZH emulation program, the measuring signal is supplied from the sound card output. It is necessary to "drive" it within 20-100 Hz at the beginning with a discrete (step) of 10 Hz. If the resonance of the GG is not visible, it is notable for a subwoofer. Or the seller you shamelessly deceived you, selling for 100 rubles. Indeline GG price from $ 200.

When the boundaries of the resonant peak are determined, "pass" it already with a discretary of 1 Hz and build ahh. If the GG is highly or the average charged closer to the upper boundary of the QTS, the schedule seems to be the fact that on the pos. I FIG. In this case:

  • According to F-le (1) on Pos. II find U (F1, F2);
  • On schedule we find F1 and F2;
  • According to F-le (2), we check whether the calculated frequency of its own resonance coincides in the free space F's with the measured FS. If the discrepancy is more than 2-3 Hz, see below;
  • According to F-le (3), we find the mechanical quality of QMS, then by F-le (4) electrical QES and, finally, according to F-le (5), the desired full QTS quality is.

If the goodness of the GG is closer to low or such, which is generally good, the resonant curve will be noticeably asymmetric, and its peak is flat, blurred, pos. Iii, or checking on F-le (2) will not occur during repeated measurements. In this case, according to the graph, we determine the point of the greatest tilt of tangents to the concave "wings" of the peak A1 and A2; Mathematically, in them, the second derivative of the function describing the resonant curve reaches the maximum. For Umax, then we take, as before, its value on the top of the peak, and for Umin - calculated by F-le on the pos. III new value U (F1, F2).

System structure

Furious? Speaker suits? Do not hurry to choose design. First you need to select the structural scheme of the entire sound system, because On its electronic part there may be a share of costs not less than a good bass speaker. The subwoofer sounding system can be built on one of the trail. Schemes, see fig.

Note: The Equalizer and Filter Filter Finch (Rocky Filter) in all circuits are turned on to stereokanal inputs.

Pos. 1 - a system with a passive plexigraration in power. Plus - do not need a separate bass amplifier, connects to any urzch. Huge drawbacks, first, mutual electrical seeping of the channels in the subwoofer in sch: For LC filters that reduce it to an acceptable value, you will need a decent case, which for the purchase of their component will have to be completely for the third to be filled with money (in 100 ruble borrowings). The second - the output resistances of the low-frequency filters of the FNH in conjunction with the input GG dynamics form a tee, and each Channel UMPs theoretically a quarter of the power will spend to warm the neighbor with its VFC. Really - more, because At the power and loss in filters are essential. However, a power prefabrication system is applicable to small power subwoofers with independent sound emitters, see below.

Pos. 2 - Passive Practitioner for Separate Bass Ump. No power loss, the mutual influence of the channels is weaker, because Characteristic filter resistance - kilometers and tens of kiloma. Currently, it is practically no applied, because Assemble the active filter on chips is much easier and cheaper than to moth passive coils.

Pos. 3 - active analog balance. The signals of the channels are folded by a simple resistor adder, come to an analog active FGH, and from it to the Bass UMP. The mutual influence of the channels is negligible and under normal listening conditions is unnoticed, the costs of components are small. The optimal scheme for the homemade subwoofer of a novice amateur.

Pos. 4 - Full digital prefixing. The channel signals are fed to the splitter P, separating each of them at least 2 equivalent source. One signal from the pair is fed to the ski-RF UMP (possibly directly, without FVCH), and the rest are combined in the adder C. The fact is that with a resistor addition on the lower frequencies of Midbas and in the subbasa, the electrical interaction of signals in the FGH, several distorting total bass. In the adder, the signals are folded with a digital or analog method that excludes their mutual influence.

From the adder, the general signal is fed to a digital FGH with built-in analog-digital (ADC) and a digital-analog (DAC) transducers, and from it to bass umzch. The quality of the sound and the junction of the channels is the maximum possible today. The costs of chips for the whole this economy are silent, but work with the IC requires some of the radio amateur experience, and even more - if not a ready-made set (which is significantly more expensive), and the components of the system are selected independently.

Registration

In fig. The most common schemes of acoustic design of domestic subwoofers are given. Maze, horn, etc. do not meet compactness requirements. Green highlighted schemes, preferred for beginners, yellow - performed by them, and red - unsuitable. Who is more expensive, may be surprised: 6th Bandpass - for dummies? Nothing terrible, this excellent bass acoustics on pipes can be configured for the weekend. If you know how.

Shield

Designing a subwoofer in the form of an acoustic screen (shield, pos. 1) at home is fear if the GG is built into the walls of the walls, because Their dimensions are commensurate with sub-wavelength lengths. Hence the dignity - with subfasses there are no problems, if only the dynamics have been pulled. Another is the limit compactness, the Sab of a useful area does not occupy at all. But there are also serious cons. The first is a large amount of construction work. The second - the acoustic screen does not affect the ACH GG. Gorbaytaya - it will be so singing, so you can put on the shield only expensive low-profile and indifferent speakers. Submills, so to speak - their returns of Mala and the shield to increase it in no way capable.

Closed box

Large plus a closed box (pos. 2) - deep damping of the GG; For inexpensive high-speed high-speed speakers, this is the only acceptable type of acoustic design. But this plus entails and minus: with deep damping the noise power of the GG often turns out to be lower than peak, especially in expensive powerful heads. The coil is already smoking, but wheezing still not heard. You need an overload indicator, but the simplest no separate power distort the signal.

No less fat plus - the extremely smooth smoothly falling frequency response and as a result is the most pure and living sound. For this reason, high-class powerful high quality GGs are manufactured specifically for installation in closed boxes or 4th order bandpass (see below).

Minus - from all the speakers of equal volume at the closed box the highest lower reproducible frequency, because It increases the resonant frequency of the speaker and is not able to increase its return at frequencies below it. Those. By compactness, the subwoofer in the closed box passes with a large stretch. To some extent, it is possible to reduce this disadvantage, by filling the box with sintepsum: it perfectly absorbs the energy of sound waves. The thermodynamic process in the box then from adiabatic transitions to isothermal, which is equivalent to an increase in its volume by 1.4 times.

Another minus - in the closed box, you can only make a passive subwoofer, because Electronics in it is greatly heated even placed in the felling compartment. If you get out old speakers 10mas-1m, drive them on half power from half an hour and touch the body with your hand - it will be warm.

F.

Note: In everything is equivalent to fi passive radiation (PI) - instead of a pipe with the port, they put a bass speaker without a magnetic system and with weight instead of a coil. "Hopeless" methods for calculating pi no, therefore, in industrial production, a rare exception. If you have a burned bass speaker, you can experiment - the setting is carried out by changing the weight of the cargo. But do not care - the active pi is better not to do for the same reason as the closed box.

About deep slots

Acoustics with deep slits (pos. 4, 6, 8-10) is identified with fi, then with a labyrinth, but in fact it is an independent type of acoustic design. Advantages in deep slit mass:

The disadvantage of the deep slit is only one, and then for beginners: inspired after the assembly. As done, so to sing.

About anti-acoustics

Bandpassa

BandPass translated the passage of the strip, so called the AC without direct radiation of sound into space. This means that the AC type of the Bandpass does not emit the scale due to the inner acoustic filtering: the speaker put in a partition between the resonating cavities communicating with the atmosphere of pipe ports or deep slots. Bandpass - Space-specific acoustic design and for fully separate speakers does not apply.

Bandpassas are separated by the magnitude of the order, and the order of the bandpassa is equal to the number of its own resonant frequencies. High-detailed GGs put in the 4th order bandpass, where to simply organize acoustic damping (pos. 5); Low- and midded - in the 6th order bandpass. A tangible difference as a sound between those and those, contrary to the common conviction, no: already on the 4th teaching the smoothing of the frequency response on the LF to 2 dB and less. The difference between them for the amateur is mainly in the complexity of the setting: to accurately set up the 4th Bandpass (see below) will have to move the partition. As for the 8th order bandpassov, then 2 more resonant frequencies are obtained due to the acoustic interaction of the same 2 resonators. Therefore, the 8th bandpassas are sometimes referred to as the 6th order bandpassas of class B.

Note: Idealized ACH on NF for some types of acoustic design are shown in Fig. red. Green dotted line - the ideal frequency response from the point of view of the psycho-physiology of hearing. Where it is clear that there is still enough work in the electric acoustics and grabs.

The amplitude-frequency characteristics of the same loudspeaker head in various acoustic design

Avtosabvofofer

Automotive subwoofers usually set or in the cargo compartment, or under the driver's seat, or for the back of the rear seat, pos. 1-3 in Fig. In the first case, the box takes a useful volume, in the second SAB works in difficult conditions and may be damaged by the legs, in the third - not every passenger will be able to endure a powerful bass directly near the ears.

Recently, the car subwoofer is increasingly making Stealth (Stealth), built into the niche of the rear wing, pos. 4 and 5. The subbasa of sufficient power is achieved by applying special autoodynamics with a diameter 12 "with a rigid diffuser, a little susceptible to the membrane effect, pos. 5. How to make a subwoofer for a car by forming a wing niche, see the next. video.

Video: Car Savbufer "Stealth" do it yourself

Easier just does not happen

A very simple subwoofer that does not require a separate bass amplifier can be made according to a scheme with independent sound emitters (from), see fig. In fact, these are two channels of GG, placed in a common long housing, installed horizontally. If the length of the box is comparable with the distance between the satellites or the width of the TV screen, the "breaking" stereo is noticeable. If listening is accompanied by viewing, then it is at all unnoticed due to the involuntary visual correction of localization of sound sources.

According to the scheme with independent of the computer, a great subwoofer for a computer is made: a drawer with speakers are placed in the far-top corner under the tabletop. The cavity under it is a resonator configured at a very low frequency, and a suddenly good subbas is cut from a small box.

Fi for subwoofer with independent of can be calculated in Speakershop. In this case, the equivalent volume of VTS takes twice as much against the measured, the resonant frequency FS is 1.4 times lower, and the complete QTS quality is 1.4 times more. The material of the box, as and everywhere further - MDF from 18 mm; At the power of the subwoofer from 50 W - from 24 mm. But it is better to place the speakers in the closed box, it can be done in this case without calculation: the length of the software inside is taken at the place of installation ranging from 0.5 m (for a computer) to 1.5 m (for a large TV). The cross-section of the box inside is determined based on the diameter of the diffuser of the speakers:

  • 6 "(155 mm) - 200х200 mm.
  • 8 "(205 mm) - 250x250 mm.
  • 10 "(255 mm) - 300x300 mm.
  • 12 "(305 mm) - 350x350 mm.

At the most worst case (a pretty computer Sab on 6 "speakers), the size of the box will be 20 liters, and equivalent to filling - 33-34 liters. With the power of UMPs up to 25-30 W per channel, this is enough to get a decent MIDBAS.

Filters

LC filters in this case it is better to use the type K. For them you need more coils, but in amateur conditions it is insignificant. In K-filters, small attenuation in the strip of improponation, 6 dB / oct on the link or 3 dB / oct on the semi-shoe, but absolutely linear FFH. In addition, when working on a voltage source (which is a great accuracy, the UML), the K-filter is little sensitive to changes in the load impedance.

On pos. 1 Fig. Damed schemes of k-filters links and calculated formulas for them. R For the LB GG is taken equal to its impedance Z at the frequency of the FNch 150 Hz, and for the PVCH equal to the satellite impedance Z on the frequency of the FVCh 185 Hz (formula for pos. 6). Z and Z are defined according to the diagram and formula in Fig. Above (with measurement schemes). Working diagrams of filters are given on pos. 2. If you like to buy capacitors more than you, and not to wind the coils, exactly the same parameters can be made up from P-links and half azhen.

Data and schemes for the manufacture of simple subwoofer filters with independent emitters

Attenuation of the FNH in a strip of impulse 18 dB / Oct, and 24 dB / Oct. Such a frankly nontrivial ratio is justified by the fact that the satellites are unloaded from the LC and give sound cleaner, and the remainder reflected from the FVCh is sent to the dynamics of the dynamics and makes bass deeper.

Data to the calculation of filter coils is given to pos. 3. They need to be mutually perpendicular to them because K-filters work without a magnetic connection between the coils. When calculating, the sizes of the coil and found in the calculation of the inductance filter determine the number of turns. Then, with the help of the stacking coefficient, the diameter of the wire in isolation is found, it should turn out at least 0.7 mm. It turns out less - we increase the size of the coil and pass.

Setting

Setting this subwoofer is reduced to align the loudscens of the bass and satellites onto the acc. Cutting frequencies. To do this, first prepare a room to acoustic measurements, as described above, and a tester with a bridge and a transformer. Next you need a condenser microphone. For a computer, you will have to make any microphone amplifier (MUS) with the supply of displacement to the capsule, because A typical sound card cannot simultaneously receive a signal and emulate GZch, pos. 4. If there is a condenser microphone with built-in MUS, at least an old MKE-101, excellent, its output is connected directly to the primary (smaller) transformer winding. Measuring procedures are easy:

  1. The microphone is fixed opposite the geometric center of satellites at a distance of horizontally 1-1.5 m.
  2. Disconnect the subwoofer from the umzch and the signal of 185 Hz is fed.
  3. Write a voltmeter readings.
  4. Without changing anything in the room, disconnect the satellites, connect the sub.
  5. Feed a 150 Hz signal to the clench, write the tester readings.

Now you need to calculate leveling resistors. Align the volume by the downstream loud links on a serial-parallel scheme (pos. 5), because It is necessary to keep the values \u200b\u200bof Z and Z found unchanged by the module. Estimated formulas for resistors are given to pos. 6. Power Rg - not less than 0.03 from the power of UMPs; Rd - any of 0.5 watts.

Too simple

Another option is simple, but already a real subwoofer - with a sprayed LF GG. Pairing the dynamics - a very effective way to increase the class of their sound. The design of the subwoofer on the asparagus of the old 10GD-30 is given in Fig. below.

Registration is very perfect, Bandpass 6th order. Bass amplifier - on TDA1562. Other high-detailed GGs with a relatively small dimension of the diffuser can be used, then it may have to make the selection of pipe length. It produces in control frequencies 63 and 100 Hz trail. way (check frequencies are not resonant acoustic system!):

  • Prepare a room, a microphone and appliances, as described above.
  • Served 63 and 100 Hz to Umzch.
  • Change the lengths of the pipes, seeking the difference of voltmeter readings not more than 3 dB (1.4 times). For gourmet - no more than 2 dB (1.26 times).

The adjustment of the resonators is interdependent, so the pipes need to move according to: pushed the short one, as much proportional to its initial length, pulled the long one. Otherwise, you can upset the system at all: the peak of the optimum settings in the 6th Bdpassy is very sharp.

  1. The failure between 63 and 100 Hz - the partition must be moved towards the larger resonator.
  2. The failures on both sides of 100 Hz - the partition is shifted towards a smaller resonator.
  3. Splash closer to 63 Hz - you need to increase the diameter of the long pipe by 5-10%
  4. A splash closer to 100 Hz is the same, but for a short pipe.

After any of the adjustable procedures, the subwoofer is placed. For its convenience, the complete assembly on the glue is not done at first: the partition is tightly adjusted with plasticine, and one of the side walls put on bilateral tape. Watch that there is no cracks!

Pipes for resonator

Ready-made crankshafts for acoustics are sold in musical and radio markets. The telescopic acoustic tube can be made with their own hands from cropping plastic or cardboard pipes. In the other case, across inland mouth, it is necessary to firmly glue 2 sections of the fishing line: one inlet, another protruding outward loop, see fig. on right. If the pipe must be pushed, pressing a pencil to the tight fishing line, etc. If you have to shorten - pull the loop. The adjustment of the resonator with the pipe is thus accelerated for many times.

Powerful 6th order

Drawings Bandpass 6th order under 12 "GG are given in Fig. This is already a solid outdoor design to power up to 100 W. Configured, as well as the previous one.

Bandpass 6th order subwoofer drawings under 12 "Speaker

4th order

Suddenly, at your disposal will be 12 "high-level GG, it will be possible to make Bandpass 4th order of the same quality, but more compact, see fig; sizes in see however it will be much more difficult to set it up, because Instead of manipulations with a tube of a larger resonator, you will have to immediately move the partition.

Sabwofer Bandpass 6th order under 12 "Speaker

Electronics

The bass urzch for the subwoofer is presented the same as the filters, the requirement of the complete linearity of FFH. It is satisfied by the urzch, made on the pavement scheme, it is an order of magnitude reduces non-linear distortion of integral umzch with not complementary output. Ump for a subwoofer with a capacity of up to 30 W can be collected according to the scheme for pos. 1 rice; 60-watt according to the scheme for pos. 2. Active subwoofer is convenient to do on the same 4-channel TDA7385 microcircuit: a pair of channels are allowed to satellites, while the other two are included on the pavement scheme on the SAB, or if it is independent of the bass. The TDA7385 is also convenient for the fact that for all 4 channels it has a common inputs of ST-BY and MUTE functions.

According to the scheme for pos. 3 It turns out a good active filter for the subwoofer. The amplification of its rationing amplifier is regulated by a variable resistor per 100,000 wide limits, therefore, in most cases, a rather short-circuit procedure for aligning saba and satellite losses is disappeared. Satellites are included in this embodiment without PVCH, and in the SC-RF amplifiers embed the potentiometers of the volume of the volume with the slots under the screwdriver.

Perhaps you want to calculate a slit sub-zero, and not bother with the reconfiguration of the prototype subwoofers under its own speaker. In this case, follow the link: //cxem.net/sound/dinamics/dinamic98.php. The author, it is necessary to give him due, managed at the level of "for dummies of the lumine" to explain how to calculate and make a high-class subwoofer with the help of modern software. However, in a big deal, not without missing, therefore, studying the source, keep in mind:


And still…

Having made the SAB, a fascinating, useful for the development of mind and skill, besides, a good bass speaker is to one and a half more cheaper pair of class below. However, on control auditions and mothers, experts, and random listeners "from the street", with other things being equal, definitely prefer the voicing systems with the full separation of the channels. So count first: do not you still have to handle and wallet a couple of separate speakers?

Sound amplifier for 60s do it yourself

So far, there is a little time, another new scheme appears on the site, everyone knows that the more power of the amplifier, the more expensive it is. But how to do if you need an amplifier and powerful and at the same time does not hit hard by pocket. I want to introduce a multiple-acquired step of the amplifier with a capacity of 25 or 60 watts, the cost of which a penny. As it was already said, the power of the amplifier depends on the supply voltage and the ratings of the resistors (the ratings of 60 watts are indicated in brackets). Umzch was collected by me and repeatedly tested in the work, he showed very high reliability.

An option was collected by 60 watts.

Sound amplifier on the TDA 2003 chip

Sound amplifier on the TDA 2003 chip

Many schemes on the Internet on the topic of the UZB, to which they can relate schemes How powerful sound amplifiers So medium. I wanted to me that I was pogromed, somehow. And thinking decided that it would take 10-20 watt amplifier. I think this is quite enough.

The design was intended for listening to music during the game on the school football field. This output power was just suitable in order to hear music in all parts of the field. This scheme will collect even a beginner, however, an experienced radio amateur wants to sometimes pamper himself with such an excellent repetition. The scheme is pretty light and stable in work.

Amplifier for subwoofer with your own hands

Amplifier for subwoofer with your own hands

The amplifier has protection against overheating, overload and smooth inclusion that eliminate cotton in the dynamics when power is turned on.

Unfortunately, the printed circuit board is not left for this amplifier.

But for those who seriously decided to take his assembly, labor will not be.

The output power of this amplifier is 100W

Amplifier scheme for subwoofer

Amplifier scheme for subwoofer

On the Internet is often looking for schemes for subwoofer, by such requests as nF scheme, or amplifier Scheme for Active Subwoofer.

But there is no LF amplifier in pure form, an ordinary amplifier is taken, even for example, whose scheme is here, you can at least those that are on our website, for example, an excellent diagram is tried and called as amplifier Ageev

Simply to output Sound on the subwoofer with low frequencies, before the audio channel is put HF filter. And still proceed to our scheme.

Amplifier scheme for column on K174UN14

Amplifier scheme for column on K174UN14

Do it yourself We will look at the article scheme How to create amplifier at K174UN14. sound frequency.

The output power of the amplifier from 5W, but in some cases they write 8W, but do not forget that sound distortions are always. Particularly on simple schemes.

Lamp amplifier circuit with photo

Lamp amplifier do it yourself

Amplifier collected on the famous lampoh 6N6P in the driver and 2 x 6P14P. in parallel in the outputm Cascade.