How to assemble your own speaker system. Making a mini speaker with an amplifier

1. Column or speaker?
2. Acoustics and electronics
3. What is hi-fi
4. Speakers
5. Acoustics

Making sound speakers with your own hands - this is where many people begin their passion for a complex, but very interesting matter - sound reproduction technology. The initial motivation is often economic considerations: prices for branded electroacoustics are not excessively inflated, but outrageously brazen. If sworn audiophiles, who do not skimp on rare radio tubes for amplifiers and flat silver wire for winding sound transformers, complain on forums that the prices for acoustics and speakers are systematically inflated, then the problem is really serious. Would you like speakers for your home for 1 million rubles? pair? If you please, there are more expensive ones. That's why The materials in this article are designed primarily for very beginners: they need to quickly, simply and inexpensively make sure that the creation of their own hands, all of which cost tens of times less money than a “cool” brand, can “sing” no worse or at least comparable. But probably, some of the above will be a revelation for the masters of amateur electroacoustics- if it is honored with reading by them.

Column or speaker?

A sound column (KZ, sound column) is one of the types of acoustic design of electrodynamic loudspeaker heads (SG, speakers), intended for technical and informational sounding of large public spaces. In general acoustic system(AS) consists of a primary sound emitter (S) and its acoustic design, which provides the required sound quality. Home speakers for the most part look like speakers, which is why they are called that. Electroacoustic systems (EAS) also include an electrical part: wires, terminals, isolation filters, built-in audio frequency power amplifiers (UMPA, in active speakers), computing devices (in speakers with digital channel filtering), etc. Acoustic design of household speakers They are usually placed in the body, which is why they look like columns more or less elongated upward.

Acoustics and electronics

The acoustics of an ideal speaker are excited over the entire range of audible frequencies of 20-20,000 Hz by one broadband primary source. Electroacoustics is slowly but surely moving towards the ideal, but the best results are still shown by speakers with frequency division into channels (bands) LF (20-300 Hz, low frequencies, bass), MF (300-5000 Hz, mid) and HF (5000 -20,000 Hz, high, high) or low-midrange and high-frequency. The first, naturally, are called 3-way, and the second - 2-way. It is best to start getting comfortable with electro-acoustics with 2-way speakers: they allow you to get sound quality up to high Hi-Fi (see below) at home without unnecessary costs and difficulties. The sound signal from the UMZCH or, in active speakers, low-power from the primary source (player, computer sound card, tuner, etc.) is distributed among frequency channels by separation filters; this is called channel defiltering, just like the crossover filters themselves.

The rest of the article focuses primarily on how to make speakers that provide good acoustics. The electronic part of electroacoustics is the subject of a special serious discussion, and more than one. Here you only need to note that, firstly, at first you do not need to take on close to ideal, but complex and expensive digital filtering, but use passive filtering using inductive-capacitive filters. For a 2-way speaker you only need one plug of low and low crossover filters. high frequencies(LPF/HPF).

There are special programs for calculating AC staircase separating filters, for example. JBL Speaker Shop. However, at home, individual tuning of each plug for a specific instance of speakers, firstly, does not affect production costs in mass production. Secondly, replacing the GG in the AC is required only in exceptional cases. This means that you can approach filtering the frequency channels of speakers in an unconventional way:

1. The frequency of the LF-MF and HF section is taken to be no lower than 6 kHz, otherwise you will not get a sufficiently uniform amplitude-frequency response (AFC) of the entire speaker in the midrange region, which is very bad, see below. In addition, with a high crossover frequency, the filter is inexpensive and compact;
2. The prototypes for calculating the filter are links and half-links of type K filters, because their phase-frequency characteristics (PFC) are absolutely linear. Without this condition, the frequency response in the crossover frequency region will be significantly uneven and overtones will appear in the sound;
3. To obtain the initial data for calculation, you need to measure the impedance (total electrical resistance) LF-MF and HF GG at the crossover frequency. The GG indicated in the passport are 4 or 8 Ohms - their active resistance is DC, and the impedance at the crossover frequency will be greater. The impedance is measured quite simply: the GG is connected to an audio frequency generator (AFG), tuned to the crossover frequency, with an output of no weaker than 10 V into a load of 600 Ohms through a resistor of obviously high resistance, for example. 1 kOhm. You can use low-power GZCH and high-fidelity UMZCH. Impedance is determined by the ratio of audio frequency (AF) voltages across the resistor and GG;
4. The impedance of the low-frequency-mid-frequency link (GG, head) is taken as the characteristic impedance of the low-pass filter (LPF), and the impedance of the HF head is taken as the head of the high-pass filter (HPF). The fact that they are different is a joke; the output impedance of the UMZCH, which “swings” the speaker, is negligible compared to both;
5. On the UMZCH side, low-pass filter and reflective-type high-pass filter units are installed so as not to overload the amplifier and not take power away from the associated speaker channel. On the contrary, the absorbing links are turned to the GG so that the return from the filter does not produce overtones. Thus, the low-pass filter and high-pass filter of the speaker will have at least a link with a half-link;

When getting into electroacoustics, you need to know the following about how speakers are structured and work in acoustic systems. The speaker exciter is a thin coil of wire that vibrates in the annular gap of the magnetic system under the influence of audio frequency current. The coil is rigidly connected to the actual sound emitter into space - a diffuser (at LF, MF, sometimes at HF) or a thin, very light and rigid dome diaphragm (at HF, rarely at MF). The efficiency of sound emission strongly depends on the diameter of the IZ; more precisely, from its ratio to the wavelength of the emitted frequency, but at the same time, with an increase in the diameter of the IZ, the probability of the occurrence of nonlinear distortions (ND) of sound due to the elasticity of the IZ material also increases; more precisely, not its infinite rigidity. They combat NI in IR by making radiating surfaces from sound-absorbing (anti-acoustic) materials.

The diameter of the diffuser is larger than the diameter of the coil, and in diffuser GGs it and the coil are attached to the speaker body with separate flexible suspensions. The diffuser configuration is a hollow cone with thin walls, with its apex facing the coil. The coil suspension simultaneously holds the top of the diffuser, i.e. its suspension is double. The generatrix of the cone can be rectilinear, parabolic, exponential and hyperbolic. The steeper the diffuser cone converges to the top, the higher the output and the lower the dynamics of the speaker, but at the same time its frequency range narrows and the directivity of the radiation increases (the radiation pattern narrows). Narrowing the pattern also narrows the stereo effect zone and moves it away from the frontal plane of the speaker pair. The diameter of the diaphragm is equal to the diameter of the coil and there is no separate suspension for it. This sharply reduces the TNI of the GG, because The diffuser suspension is a very noticeable source of sound, and the material for the diaphragm can be very hard. However, the diaphragm is capable of producing sound well only at fairly high frequencies.

The coil and diffuser or diaphragm together with suspensions make up the moving system (MS) of the GG. The PS has a frequency of its own mechanical resonance Fр, at which the mobility of the PS sharply increases, and a quality factor Q. If Q>1, then a speaker without correctly selected and executed acoustic design (see below) at Fр will wheeze at a power less than the rated one, not to mention peak, this is the so-called. locking the GG. Blocking does not apply to distortion, because is a design and manufacturing defect. If 0.7

The efficiency of transferring electrical signal energy to sound waves in the air is determined by the instantaneous acceleration of the diffuser/diaphragm (who is familiar with mathematical analysis - the second derivative of its displacement with respect to time), because air is an easily compressible and very fluid medium. The instantaneous acceleration of the coil pushing/pulling the diffuser/diaphragm must be somewhat greater, otherwise it will not “swing” the IZ. A few, but not by much. Otherwise, the coil will bend and cause the emitter to vibrate, which will lead to the appearance of NI. This is the so-called membrane effect, in which longitudinal elastic waves propagate in the diffuser/diaphragm material. Simply put, the diffuser/diaphragm should “slow down” the coil a little. And here again there is a contradiction - the more the emitter “slows down”, the more powerfully it emits. In practice, the “braking” of the emitter is done in such a way that its NI in the entire range of frequencies and powers falls within the norm for a given Hi-Fi class.

Note, output: Don't try to "squeeze" out of the speakers what they can't do. For example, a speaker on a 10GDSH-1 can be built with an uneven frequency response in the midrange of 2 dB, but in terms of SOI and dynamics it still reaches Hi-Fi no higher than the initial one.

At frequencies up to Fp, the membrane effect never appears; this is the so-called. piston mode of operation of the GG - the diffuser/diaphragm simply moves back and forth. Higher in frequency, the heavy diffuser can no longer keep up with the coil, membrane radiation begins and intensifies. At a certain frequency, the speaker begins to radiate only like a flexible membrane: at the junction with the suspension, its diffuser is already motionless. At 0.7

The membrane effect dramatically improves the efficiency of the GG, because the instantaneous accelerations of vibrating sections of the IZ surface turn out to be very large. This circumstance is widely used by designers of high-frequency and partly mid-range generators, the distortion spectrum of which immediately goes into ultrasound, as well as when designing generators not for Hi-Fi. SOI GG with a membrane effect and the evenness of the frequency response of speakers with them strongly depend on the mode of the membrane. At zero mode, when the entire surface of the IZ trembles as if to its own rhythm, Hi-Fi up to medium inclusive can be achieved at low frequencies, see below.

Note: the frequency at which the GG switches from the “piston to the membrane”, as well as the change in the membrane mode (not growth, it is always an integer) significantly depend on the diameter of the diffuser. The larger it is, the lower in frequency and the stronger the speaker begins to “membrane”.

Woofers

High-quality piston LF GGs (simply “pistons”; in English woofers, barking) are made with a relatively small, thick, heavy and rigid anti-acoustic diffuser on a very soft latex suspension, see position 1 in Fig. Then Fр turns out to be below 40 Hz or even below 30-20 Hz, and Q

The periods of LF waves are long, all this time the diffuser in piston mode must move with acceleration, therefore the diffuser stroke is long. Low frequencies without acoustic design are not reproduced, but it is always closed to one degree or another, isolated from free space. Therefore, the diffuser has to work with a large mass of so-called. attached air, the “swing” of which requires significant force (which is why piston GGs are sometimes called compression), as well as for the accelerated movement of a heavy diffuser with a low quality factor. For these reasons, the magnetic system of the piston GG has to be made very powerful.



Despite all the tricks, the recoil of piston engines is small, because It is impossible for a low-frequency diffuser to develop high acceleration at long waves: the elasticity of the air is not enough to absorb the energy given off. It will spread to the sides, and the speaker will go into locking. To increase the efficiency and smoothness of the moving system (to reduce the SOI at high power levels), designers go to great lengths - they use differential magnetic systems, with half-scattering and other exotic ones. SOI is further reduced by filling the magnetic gap with a non-drying rheological fluid. As a result, the best modern “pistons” achieve a dynamic range of 92-95 dB, and the THD at nominal power does not exceed 0.25%, and at peak power – 1%. All this is very good, but the prices - mom, don't worry! $1000 per pair with differential magnets and rheofill for home acoustics selected for impact, resonant frequency and flexibility of the moving system is not the limit.

Note: LF GG with rheological filling of the magnetic gap are suitable only for LF links of 3-way speakers, because completely unable to operate in membrane mode.

Piston GGs have one more serious flaw: without strong acoustic damping, they can be mechanically destroyed. Again, simply: behind the piston speaker there must be some kind of air bag. Otherwise, the diffuser at the peak will be torn off the suspension and it will fly out along with the coil. Therefore, “pistons” cannot be installed in every acoustic design, see below. In addition, piston GGs do not tolerate forced braking of the PS: the coil burns out immediately. But this is already a rare case; speaker cones are usually not held by hand and matches are not inserted into the magnetic gap.

Note to craftsmen

There is a well-known “folk” way to increase the efficiency of piston engines: an additional ring magnet is firmly attached with the repelling side to the standard magnetic system from the rear, without changing anything in the dynamics. It is repelling, otherwise, when a signal is given, the coil will immediately be torn off from the diffuser. In principle, it is possible to rewind the speaker, but it is very difficult. And never before has a single speaker gotten better from rewinding, or at least remained the same.

But that’s not really what we’re talking about. Enthusiasts of this modification claim that the field of the external magnet concentrates the field of the standard one near the coil, which causes the acceleration of the PS and recoil to increase. This is true, but Hi-Fi GG is a very precisely balanced system. The returns actually increase a little. But at its peak, SOI immediately “jumps” so that sound distortions become clearly audible even to inexperienced listeners. At nominal, the sound may become even cleaner, but without Hi-Fi speakers it’s already high-fi.

Presenters

So in English (managers) they are called SCH GG, because. It is the midrange that accounts for the overwhelming majority of the semantic load of the musical opus. The requirements for the midrange of the GG for Hi-Fi are much softer, so most of them are made of a traditional design with a large diffuser cast from cellulose pulp along with the suspension, pos. 2. Reviews about midrange GG dome and with metal diffusers are contradictory. The tone prevails, they say, the sound is harsh. Classical lovers complain that bowed speakers squeal from “non-paper” speakers. Almost everyone recognizes the sound of the midrange GG with plastic diffusers as dull and at the same time harsh.

The stroke of the MF GG diffuser is made short, because its diameter is comparable to the wavelengths of the midrange and the transfer of energy into the air is not difficult. To increase the attenuation of elastic waves in the diffuser and, accordingly, reduce the NI together with the expansion of the dynamic range, finely chopped silk fibers are added to the mass for casting the Hi-Fi midrange GG diffuser, then the speaker operates in piston mode in almost the entire midrange range. As a result of applying these measures, the dynamics of modern midrange GGs of the average price level turns out to be no worse than 70 dB, and the THD at the nominal value is no higher than 1.5%, which is quite enough for high Hi-Fi in a city apartment.

Note: Silk is added to the cone material of almost all good speakers; it is a universal way to reduce the SOI.

Tweets

In our opinion - tweeters. As you may have guessed, these are tweeters, HF GG. Spelled with one t, this is not the name of a social network for gossip. Make a good "squeaker" from modern materials It would be generally simple (the LR spectrum immediately goes into ultrasound), if not for one circumstance - the diameter of the emitter in almost the entire HF range turns out to be of the same order of magnitude or less than the wavelength. Because of this, interference is possible at the emitter itself due to the propagation of elastic waves in it. In order not to give them a “hook” for radiation into the air at random, the diffuser/dome of the HF GG should be as smooth as possible; for this purpose, the domes are made of metallized plastic (it absorbs elastic waves better), and the metal domes are polished.

The criterion for choosing high-frequency GGs is indicated above: dome ones are universal, and for fans of the classics who definitely require “singing” soft tops, diffuser ones are more suitable. It is better to take these elliptical ones and place them in the speakers, orienting their long axis vertically. Then the speaker pattern in the horizontal plane will be wider, and the stereo area will be larger. There is also an HF GG with a built-in horn on sale. Their power can be taken at 0.15-0.2 of the power of the low-frequency section. As for the technical quality indicators, any HF GG is suitable for Hi-Fi of any level, as long as it is suitable in terms of power.

Shiriki

This is a colloquial nickname for broadband GG (GGSH), which does not require filtering of speaker frequency channels. A simple GGSH emitter with general excitation consists of a LF-MF diffuser and a HF cone rigidly connected to it, pos. 3. This is the so-called. coaxial emitter, which is why GGSH are also called coaxial speakers or simply coaxials.

The idea of ​​the GGSH is to give the membrane mode to the HF cone, where it will not do much harm, and let the diffuser at the LF and at the bottom of the midrange work “on a piston”, for which purpose the LF-MF diffuser is corrugated across. This is how broadband GGs are made for initial, sometimes mid-range Hi-Fi, for example. the mentioned 10GD-36K (10GDSH-1).

The first HF cone GGSH went on sale in the early 50s, but never achieved a dominant position in the market. The reason is a tendency to transient distortion and a delay in the attack of sound because the cone dangles and wobbles from the shocks of the diffuser. Listening to Miguel Ramos play a Hammond electric organ through a coaxial cone is unbearably painful.

Coaxial GGSH with separate excitation of LF-MF and HF emitters, pos. 4 do not have this drawback. In them, the HF section is driven by a separate coil from its own magnetic system. The HF coil sleeve passes through the LF-MF coil. The PS and magnetic systems are located coaxially, i.e. along one axis.

GGSH with separate excitation at LF are not inferior to piston GG in all technical parameters and subjective assessments of sound. Modern coaxial speakers can be used to build very compact speakers. The disadvantage is the price. A coaxial for high-end Hi-Fi is usually more expensive than a LF-MF + HF set, although it is cheaper than a LF, MF and HF GG for a 3-way speaker.

Auto

Car speakers are formally also classified as coaxial, but in reality they are 2-3 separate speakers in one housing. HF (sometimes also midrange) GG are suspended in front of the LF GG diffuser on a bracket, see on the right in Fig. at first. Filtering is always built-in, i.e. There are only 2 terminals on the body for connecting wires.

Car speakers have a specific task: first of all, to “shout out” the noise in the car’s interior, so their designers don’t particularly struggle with the membrane effect. But for the same reason, car speakers need a wide dynamic range, at least 70 dB, and their diffusers are necessarily made with silk or other measures are used to suppress higher membrane modes - the speaker should not wheeze even in a car while driving.

As a result, car speakers are, in principle, suitable for Hi-Fi up to medium, inclusive, if you choose a suitable acoustic design for them. In all the speakers described below, you can install auto speakers of a suitable size and power, then there will be no need for a cutout for the HF GG and filtering. One condition: the standard terminals with clamps must be very carefully removed and replaced with lamellas for unsoldering. Speakers from car speakers modern developments allow you to listen to good jazz, rock, even individual works of symphonic music and many chamber music. Of course, they won’t be able to handle Mozart’s violin quartets, but very few people listen to such dynamic and meaningful opuses. A pair of car speakers will cost several times, up to 5 times, less than 2 sets of GG with filter components for a 2-way speaker.

Frisky

Friskers, from frisky, is how American radio amateurs nicknamed small-sized low-power GGs with a very thin and light diffuser, firstly, for their high output - a pair of “frisky” 2-3 W each sound a room of 20 square meters. m. Secondly – ​​for the hard sound: “fast” ones work only in membrane mode.

Manufacturers and sellers do not classify “frisky” people as a special class, because they are not supposed to be hi-fi. The speaker is like a speaker, like any Chinese radio or cheap computer speakers. However, on the “fast” you can do good speakers for a computer, providing Hi-Fi up to medium inclusive in the vicinity of the desktop.

The fact is that the “fast” ones are capable of reproducing the entire audio range; you just need to reduce their SOI and smooth out the frequency response. The first is achieved by adding silk to the diffuser; here you need to be guided by the manufacturer and its (not trade!) specifications. For example, all GG of the Canadian company Edifier with silk. By the way, Edifier is a French word and is read “ediffier”, and not “idifier” in the English manner.

The frequency response of “fast” ones is equalized in two ways. Small splashes/dips are already removed by silk, and larger bumps and depressions are eliminated by acoustic design with free access to the atmosphere and a damping pre-chamber, see fig; For an example of such an AS, see below.



Acoustics

Why do you need acoustic design at all? At low frequencies, the dimensions of the sound emitter are very small compared to the length of the sound wave. If you simply place the speaker on the table, the waves from the front and rear surfaces of the diffuser will immediately converge in antiphase, cancel each other out, and no bass will be heard at all. This is called an acoustic short circuit. You cannot simply mute the speaker from the rear to the bass: the diffuser will have to strongly compress a small volume of air, which will cause the resonance frequency of the PS to “jump” so high that the speaker simply will not be able to reproduce bass. This implies the main task of any acoustic design: either to extinguish the radiation from the back side of the GG, or to turn it 180 degrees and re-radiate it in phase from the front of the speaker, while at the same time preventing the energy of the diffuser movement from being spent on thermodynamics, i.e. on the compression-expansion of air in the speaker housing. An additional task is, if possible, to form a spherical sound wave at the output of the speaker, because in this case, the stereo effect zone is widest and deepest, and the influence of room acoustics on the sound of the speakers is the least.

Note, important consequence: For each speaker enclosure of a specific volume with a specific acoustic design, there is an optimal range of excitation powers. If the power of the IZ is low, it will not pump up the acoustics; the sound will be dull and distorted, especially at low frequencies. An excessively powerful GG will go into thermodynamics, causing blocking to begin.

The purpose of the speaker cabinet with acoustic design is to ensure the best reproduction of low frequencies. Strength, stability, appearance – of course. Acoustically, home speakers are designed in the form of a shield (speakers built into furniture and building structures), an open box, an open box with an acoustic impedance panel (PAS), a closed box of normal or reduced volume (small-sized speaker systems, MAS), a bass reflex (FI), passive radiator (PI), direct and reverse horns, quarter-wave (QW) and half-wave (HF) labyrinths.

Built-in acoustics are a subject of special discussion. Open boxes from the era of tube radios; it is impossible to get acceptable stereo from them in an apartment. Among others, it is best for a beginner to choose the PV labyrinth for his first AS:

• Unlike others, except FI and PI, the PV labyrinth allows you to improve the bass at frequencies below the natural resonant frequency of the woofer speaker.
• Compared to FI PV, the labyrinth is structurally and simple to set up.
• Compared to PI PV, the labyrinth does not require expensive purchased additional components.
• The elbowed PV labyrinth (see below) creates a sufficient acoustic load for the GG, while at the same time having a free connection with the atmosphere, which makes it possible to use LF GG with both long and short diffuser strokes. Up to replacement in already built speakers. Of course, only a couple. The emitted wave in this case will be practically spherical.
• Unlike all but a closed box and a HF labyrinth, an acoustic speaker with a MF labyrinth is capable of smoothing out the frequency response of the LF GG.
• Speakers with a PV labyrinth are structurally easily stretched into a tall, thin column, which makes them easier to place in small rooms.

Regarding the penultimate point - are you surprised if you are experienced? Consider this one of the promised revelations. And see below.

PV labyrinth

Acoustic design such as a deep slot (Deep Slot, a type of HF labyrinth), pos. 1 in Fig., and a convolutional inverse horn (item 2). We will touch on the horns later, but as for the deep slot, it is actually a PAS, an acoustic shutter that provides free communication with the atmosphere, but does not release sound: the depth of the slot is a quarter of the wavelength of its tuning frequency. This can be easily verified by using a highly directional microphone to measure the sound levels in front of the speaker and in the opening of the slit. Resonance at multiple frequencies is suppressed by lining the slot with a sound absorber. A speaker with a deep slot also dampens any speaker, but increases its resonant frequency, although less than a closed box.



The initial element of the PV labyrinth is an open half-wave tube, pos. 3. It is unsuitable as an acoustic design: while the wave from the rear reaches the front, its phase will flip another 180 degrees, and the same acoustic short circuit will result. In the frequency response of the PV pipe, it gives a high sharp peak, causing blocking of the GG at the tuning frequency Fn. But what is already important is that Fn and the frequency of the GG’s own resonance f (which is higher – Fр) are theoretically in no way related to each other, i.e. You can count on improved bass below f (Fр).

The simplest way to turn a pipe into a labyrinth is to bend it in half, pos. 4. This will not only phase the front with the rear, but also smooth out the resonant peak, because The wave paths in the pipe will now be of different lengths. In this way, in principle, you can smooth out the frequency response to any predetermined degree of evenness, increasing the number of bends (it should be odd), but in reality it is very rare to use more than 3 bends - wave attenuation in the pipe interferes.

In the chamber PV labyrinth (position 5), the knees are divided into the so-called. Helmholtz resonators - tapering towards the rear end of the cavity. This also improves the damping of the GG, smoothes the frequency response, reduces losses in the labyrinth and increases the radiation efficiency, because the rear exit window (port) of the labyrinth always works with “support” from the side of the last chamber. Having separated the chambers into intermediate resonators, pos. 6, it is possible with a diffuser GG to achieve an frequency response that almost satisfies the requirements of absolute Hi-Fi, but setting up each of a pair of such speakers requires about six months (!) of the work of an experienced specialist. Once upon a time, in a certain narrow circle, a labyrinth-chamber speaker with a separation of chambers was nicknamed Cremona, with a hint of the unique violins of Italian masters.

In fact, to obtain the frequency response for high Hi-Fi, just a couple of cameras per knee is enough. Drawings of speakers of this design are shown in Fig; on the left - Russian design, on the right - Spanish. Both are very good floor-standing acoustics. “For complete happiness,” it would not hurt the Russian woman to borrow the Spanish rigidity connections that support the partition (beech sticks with a diameter of 10 mm), and in return, smooth out the bend of the pipe.



In both of these speakers one more thing appears useful property chamber labyrinth: its acoustic length is greater than the geometric one, because the sound lingers somewhat in each chamber before passing on. Geometrically, these labyrinths are tuned to somewhere around 85 Hz, but measurements show 63 Hz. In reality, the lower limit of the frequency range turns out to be 37-45 Hz, depending on the type of low-frequency generator. If the filtered speakers from the S-30B are moved into such enclosures, the sound changes amazingly. For the better.



The excitation power range for these speakers is 20-80 W peak. Sound-absorbing lining here and there - padding polyester 5-10 mm. Tuning is not always necessary and is not difficult: if the bass is a bit muffled, cover the port symmetrically on both sides with pieces of foam until optimal sound is obtained. This should be done slowly, listening to the same section of the soundtrack each time for 10-15 minutes. It must have strong midranges with a steep attack (control of the midrange!), for example, a violin.

Jet Flow

The chamber labyrinth is successfully combined with the usual convoluted labyrinth. An example is the desktop acoustic system Jet Flow (jet flow) developed by American radio amateurs, which created a real sensation in the 70s, see fig. on right. The inside width of the case is 150-250 mm for speakers 120-220 mm, incl. “fast” and autodynamics. Body material – pine, spruce, MDF. No sound-absorbing lining or adjustment is required. The excitation power range is 5-30 W peak.

Note: There is now confusion with Jet Flow - inkjet sound emitters are sold under the same brand.

For the frisky and the computer

It is possible to smooth out the frequency response of car speakers and “fast” ones in an ordinary convoluted labyrinth by installing a compression damping (non-resonating!) pre-chamber in front of the entrance to it, designated K in Fig. below.



This mini-acoustic system is designed for PCs to replace the old cheap ones. The speakers used are the same, but the way they start to sound is simply amazing. If the diffuser is made of silk, otherwise there is no point in fencing the garden. An additional advantage is the cylindrical body, on which the midrange interference is close to minimal; it is less only on the spherical body. Working position – tilted forward and upward (AC – sound spotlight). Excitation power – 0.6-3 W nominal. Assembly is carried out as follows. order (glue - PVA):

• For children 9 glue the dust filter (you can use scraps of nylon tights);
• Det. 8 and 9 are covered with padding polyester (indicated in yellow in the figure);
• Assemble the package of partitions using screeds and spacers;
• Glue in padding polyester rings, marked in green;
• The package is wrapped, gluing, with whatman paper until the wall thickness is 8 mm;
• The body is cut to size and the antechamber is pasted over (highlighted in red);
• They glue the children. 3;
• After complete drying, they sand, paint, attach a stand, and mount the speaker. The wires to it run along the bends of the labyrinth.

About horns

Horn speakers have high output (remember why they have a horn in the first place). The old 10GDSH-1 screams through its horn so loudly that your ears wither, and the neighbors “can’t be happier,” which is why many people get carried away with horns. Home speakers use convoluted horns as they are less bulky. The reverse horn is excited by the back radiation of the GG and is similar to the PV labyrinth in that it rotates the phase of the wave by 180 degrees. But otherwise:

1. Structurally and technologically it is much more complicated, see fig. below.
2. It does not improve, but on the contrary, it spoils the frequency response of the speakers, because The frequency response of any horn is uneven and the horn is not a resonating system, i.e. It is impossible in principle to correct its frequency response.
3. The radiation from the horn port is significantly directional, and its waveform is more flat than spherical, so one cannot expect a good stereo effect.
4. It does not create a significant acoustic load on the GG and at the same time requires significant power for excitation (let’s also remember whether they whisper into a speaking speaker). The dynamic range of horn speakers can be extended, at best, to basic Hi-Fi, and in piston speakers with a very soft suspension (that is, good and expensive ones), the diffuser breaks out very often when the GG is installed in the horn.
5. Gives more overtones than any other type of acoustic design.



Frame

The housing for the speakers is best assembled using beech dowels and PVA glue; its film retains its damping properties long years. To assemble, one of the side panels is placed on the floor, the bottom, lid, front and back walls, partitions are placed, see fig. on the right, and cover with the other side. If the external surfaces are subject to final finishing, you can use steel fasteners, but always with gluing and sealing (plasticine, silicone) of non-adhesive seams.



The choice of housing material is much more important for sound quality. Perfect option- a musical spruce without knots (they are a source of overtones), but it is unrealistic to find large boards of it for speakers, since spruce trees are very knotty trees. As for plastic speaker enclosures, they only sound good industrial production solid cast, and amateur homemade products from transparent polycarbonate etc. these are means of self-expression, not acoustics. They will tell you that this sounds good - ask to turn it on, listen and believe your ears.

In general with natural wood materials It’s difficult for speakers: completely straight-grained pine without defects is expensive, and other available building and furniture species produce overtones. It is best to use MDF. The above-mentioned Edifier has long since completely switched to it. The suitability of any other tree for AS can be determined by following. way:

1. The test is carried out in a quiet room, in which you yourself need to first stay in silence for half an hour;
2. A piece of board approx. long. 0.5 m is placed on prisms made from sections of steel angles, laid at a distance of 40-45 cm from each other;
3. The knuckle of a bent finger is used to knock approx. 10 cm from any of the prisms;
4. Repeat tapping exactly in the center of the board.

If in both cases the slightest ringing is not heard, the material is suitable. The softer, duller and shorter the sound, the better. Based on the results of such a test, you can make good speakers even from chipboard or laminate, see the video below:

Video: a simple do-it-yourself laminate speaker for your phone

Spikes

Floor-standing and tabletop speakers are installed on special legs - acoustic spikes - which prevent the exchange of vibrations between the speakers and the floor or tabletop. Acoustic spikes are available for sale, but the prices are, you know, a special product. So, weights for construction and carpentry plumb lines have exactly the same configuration (a cylinder turning into a cone with a rounded nose) and material properties. Price - you understand. Feel free to place any speakers on spikes made of plumb weights; they will cope with an unusual task for them perfectly.

Unfortunately, not every one of us can afford to have a high-quality speaker system in the house. Now even the cheapest option will cost at least 10 thousand rubles. However, why not buy low-quality speakers that make a squeaking sound? If you are so eager to have your own in your home, you can make it yourself.

Moreover, all suitable parts and elements can be purchased almost anywhere, and their cost will certainly not be 10 thousand rubles. How to do it yourself? You will learn about this from our article today.

Preparing tools

So, during the work we will need the following materials and tools:

• screwdriver;
• chipboard sheet or MDF (for making the speaker system housing);
• marker;
• jigsaw;
• PC power supply 400 W;
• radio;
• Bulgarian;
• a pair of acoustic speakers;
• furniture screws and self-tapping screws;
• sealant (it is best to use silicone based);
• voltmeter and glue.

Before assembling, first check the operation of the radio and find out whether it can be powered or not. It is also necessary to test the speakers for sound quality. After this, you can safely begin manufacturing the housing and other elements of the speaker system.

Case manufacturing

As walls for the column, you can use a regular sheet of MDF or chipboard. In this case, it is unacceptable to use plywood, since according to its characteristics it is very flexible and produces a strong resonance. When making a housing for the speaker system, also take into account the fact that the more air remains inside the box, the softer the bass will be. Therefore, leave as much free space as possible, but everything should be in moderation (otherwise such speakers will simply be impossible to transport).

Place the shelf so that the speakers are exposed to maximum amount air. Next, mark the places for cutting with a marker. Now you can safely cut a sheet of chipboard with a jigsaw. We also note that the edges of the cut parts of the tree should be carefully aligned. To do this, use a small construction grinder. Please note that it can work with several discs - for metal and wood. We need the latter option, since when processing such materials cutting element the first type simply wears off and even smokes. Experts recommend using a petal circle.

Now the matter remains small. On the body, mark places for screwing in furniture screws and use a screwdriver to screw them in completely. In the case of screws, first make markings for them and drill through holes. That's it, the housing for the speaker system has been successfully manufactured.

Wall fasteners

Emphasis should be placed on the strength of the wall fasteners. Don't skimp on screws and self-tapping screws. The design of the speaker housing should be as strong and durable as possible. If the number of screws is insufficient, the system walls will rattle heavily under heavy load, thereby only worsening the sound quality.

Thorough assembly

How do you make a three-lane with your own hands? After you have made the case (the so-called “monoblock”), you can begin to thoroughly assemble the structure. Here it is best to use a cordless screwdriver with a 4mm hexagon to tighten the screws. Remember that inside the speaker its own sound load is distributed from minimum to maximum - bottom wall, top, front and side.

How to do it yourself next? At the next stage, the joints should be treated with silicone sealant. This is necessary in order to prevent excess from penetrating out of the case through the cracks. Thus, the level of music playback will become even better. How then do you make an acoustic system with your own hands? After lubricating all the cracks with sealant, you will need to install the speakers and radio. The latter is best purchased at assembled form. The speakers, together with the radio, are installed through holes made in the bottom wall of the monoblock.

When everything is ready, the final design should look like this: on the back of the monoblock there is a power supply, two speakers on the sides (with each of them located in a separate column) and a car radio in the middle. Making speaker systems with your own hands occurs in a certain order of actions - first the power supply is mounted, and then the radio tape recorder. This will make it much more convenient for you to screw fasteners. But at this stage, the PC has not yet been completely assembled. Next, you will need to reinforce the corners. We will tell you about this in the next section.

How to make a speaker system with your own hands? Strengthening corners

The whole point of the work is to paste over certain parts of the monoblock and then install square or triangular glazing beads on them. It is not necessary to use Moment as an adhesive. Regular PVA will do the job quite well. Before applying glue to the surface of the material, make sure that it is dry and that its surface is free of cracks and bends.

What needs to be done in order for the power supply to work?

To do this, you will need to put a jumper on the wide, large connector (in other words, short it). Here it is enough to use a regular paper clip. Use it to connect two wires (green to black) and check the functionality of the device with a voltmeter.

To ensure that these elements have greater conductivity, after installing the contact, thoroughly solder their connection points. Now insert the block body inside the monoblock and attach it with self-tapping screws. Also treat any resulting cracks with sealant.

About sound-permeable material

At the next stage, the acoustic system, made by yourself, is filled with a special sound-permeable material (here you can use ordinary padding polyester). They need to fill the entire volume of the columns.

However, you cannot apply it to the diaphragm. This sound-permeable material significantly reduces the load on the walls of the system and reduces the speed of sound waves. So, when playing a melody, the speaker design will practically not vibrate. However, you should not follow the principle “the more, the better.” If you overfill the speaker with synthetic padding, it may lose bass and, accordingly, the sound quality will deteriorate significantly.

Fan

If your TV or computer speaker system is designed for high output power, consider additional elements cooling.

Indeed, under high load, the elements of the speakers become very hot, which can cause their premature failure. And you need to install the fan in such a way that it blows from the inside to the outside, that is, the hot air is brought out into the street (or room). If the heat from the radio is removed, overheating of system parts will be eliminated, and your speakers will last a very long time. long time. At this stage, the question of how to make a three-way speaker system with your own hands can be considered closed.

Today I will tell you, dear Durkovites, how with my own hands do what it costs in the store big money. That is, a good speaker system. I remember once posting here about the S-30, and from that moment I started making my own speaker like this from scratch.

Let me start with the fact that when I found this pair of S-30s in a barn at the dacha, I was almost stupefied - not only are they different (one is s-30B, the other is S-30A), but one of them also has a broken body. The second one did not have a filter inside; someone had already removed it before me. There was no point in doing restyling - they are too different, and I didn’t know how to restore the half-rotten body. And why, when you can remake 2 identical ones. The woofers, GDN-25, are in perfect condition, but it’s better to install new tweeters. Well, let's begin.
Part one. Columns.

I didn’t think about the material for a long time - the walls were from some kind of Soviet sideboard (16 mm chipboard), and with holes. We fill the holes with pva dowels. Next we cut to size. Oh yes, the most important thing is the size. I took approximately the same dimensions as the original S-30, only slightly changed the shape. But the bass reflex had to be calculated in SpeakerShop. I took it with a margin of 50 mm. We twist the body with self-tapping screws, this is still a fitting.

We disassemble, apply glue, and assemble. We glue glazing beads into the corners for added strength:






Now we dampen everything with linoleum, the furry side inward:






We collect completely.








Now that everything is working for us and there is no whistling anywhere, we can putty.




Well, now the most tedious and dusty part - sanding...


After a couple of hours, you get something smooth and velvety. Can be pasted over. At first I wanted black self-adhesive to look like wood, but in our, sorry, mukhosransk there was none. But how nice it is to have friends in other cities! In a month I will of course have it, but for now I’ll have to cover it with what I have. something like this:








In order not to mess around with the style of the front panel, we make a black acoustic grill. (It’s better to make it from acoustic fabric, but if your budget is tight, you can get by with women’s black tights; you can’t tell them apart by appearance. The most important thing is to ask your girlfriend/friend/mother for permission to take these same tights. Sometimes they cost many times more than the acoustic fabric itself , so be careful ;))










It turns out no worse than purchased ones, it seems to me:




While I was making the amplifier (more on that later), they brought me some self-adhesive tape. My joy knew no bounds!





And now the most important thing - don’t skimp on connectors! I first bought Chinese ones for 15 rubles, and was very disappointed. At low frequencies they produce very unpleasant sounds, what not to do with them. Therefore, I bought some branded ones, with gold-plated contacts. Believe me, this greatly affects the sound. The extra 300 rubles are worth it.


Now we install the tweeter. I bought car speakers, I couldn’t find normal ones from us, I picked out the speakers themselves from the case, and placed them in a hollowed-out recess using PVA-based putty.


Well, and most importantly, because... I had to remove the domes on the woofers due to their rattling, so I made new ones with my initials :)

Needless to say, the sound turned out to be no worse than branded speakers of famous audiophile trends.

Part two. Amplifier.
The speakers turned out just like the original, 30 watts each - 25 watts LF and 5 watts HF (although according to the documents it is written that these tweeters are 60 watts each, but it’s more expensive for the Chinese to believe themselves. The sound is no more than 5 watts) At first I had an amplifier - I assembled a year ago from an AT power supply and a TDA1558Q mikruhi. But firstly, there are only 44 watts, and secondly, this mikruha pulls out the bass rather weakly. I didn’t think about choosing a microcircuit for a long time - TDA 8560Q. Similar to the previous one, only the output is up to 80 W, + the signal quality is higher and there is less distortion. I immediately warn beginners - it’s better not to assemble anything on the 8560, it’s very capricious. But if your hands grow from the right place, you will get a wonderful amplifier. While assembling mine, I burned two of them. And they cost about 150 rubles apiece, which is money I feel sorry for, so I have honed my stock of obscene language well. The case will be made of one-sided foil fiberglass. Convenient, lightweight, and does not conduct current where it is not needed. It is also a wonderful mass, screen and antenna (if you connect a phone with a radio receiver)


We mark, cut with a jigsaw, drill the necessary holes:

I couldn’t resist and tried on future connectors :)


We sand the solder joints and tin.


We heat the tinned areas with a soldering iron and everything sets wonderfully:




Now we putty all the cracks and joints with auto putty. A day later we safely sand and polish.






Let's try the filling:




Everything works, you can paint it. We paint it with glossy black paint, after which we sand down the defects.




And now the main highlight is the aluminum inserts. A parody of expensive amplifiers, it’s like protective steel corners. We cut it out of a 3mm sheet of luminium, bend it to the shape of the front panel, add a texture with sandpaper, and screw it in with hex bolts (that’s bolts, this is also part of the design). Looks Cute:


We remove all the props and take out the filling. We paint normally:




The result is this small wonderful case:

Now about the filling. Microwave Tda8560 on a radiator from a 300th celeron, a transformer (which is at least 40 years old, but produces about 15A and 12V), a diode bridge of about 12A and 3 capacitors: 4700 µF, 2200 µF and 0.47 µF connected in parallel. Two condensers at the signal inputs of the mikruhi, 0.05 microfarads each (also Soviet, much better than the Chinese ones), and a dual input variable resistor at 50 kOhm. Cooler (remained from the computer power supply, it was the one that was installed at first) 2 and blue LEDs below. That’s the whole circuit.






And so that the 2-kilogram transformer does not warp the body, we strengthen it with two corners and a steel plate at the base, on which everything is actually attached.


Now we make the bottom from the same PCB and the legs from a nickel-plated furniture tube:

Looks good next to my system unit, the same blue backlight (in the photo, unfortunately, the computer is turned off):

Part three. The final.

Now everything is assembled and it works great. In total it took me about three months. And I’ll say right away that here are only a third of the photographs, the rest show what went wrong with me, after all, this is my first project with such precision and such high-quality elaboration of every detail.

P.S. I’m in 10th grade, and this is supposedly my project for the regional technology Olympiad, at which, by the way, I took first place 3 days ago.

Happy modding! Sincerely yours, Viktor Sarbaev.

A speaker is an acoustic system of very modest size, containing one or more loudspeakers with a built-in amplifier. Speakers are used to increase the volume of sound, and the sound is increased by speakers. Speakers consist of two magnets: usually a ceramic permanent magnet and an electric magnet, which is controlled by an audio amplifier. Thanks to these magnets, sound is produced when they interact. Speakers are divided into two more categories: passive - that is, in which there is no built-in audio amplifier, for example, headphones; and active - respectively, speakers that have their own built-in audio amplifier. The active speaker system has its own power supply. In this article you will see how to make a homemade active speaker system with your own hands. This speaker can be connected to a computer, a phone, a player, and so on. To make this homemade product I needed:

Materials:
1) Two speakers with a power of 3 watts each (they will serve as a sound source);
2) Three and a half millimeter plug for connecting the speaker to various devices;
3) (the amplifier will receive sound signals from some device and transmit them to the speakers, amplifying these signals);
4) Switch to turn off the speaker power;
5) Wires for connecting contacts;
6) Insulating tape for insulating wires and other needs;
7) USB plug for connecting to power;
8) Heat-shrinkable tubes for insulating exposed contacts;
9) Plywood (the body will be made from plywood, since this is the most affordable material);
10) Self-tapping screws for assembling the housing.

Tools:
1) Electric soldering iron for soldering wires;
2) Glue gun and hot melt adhesive for gluing some parts and for insulating contacts;
3) Stationery knife for cleaning wires from insulation and for other needs;
4) Lighter for heat shrink tubes;
5) Hacksaw for sawing plywood;
6) Jigsaw for cutting round and other holes on plywood;
7) Electric drill for drilling holes;
8) Screwdriver for tightening screws;
9) Ruler and pencil for drawing marks on plywood for the speaker body;
10) Sandpaper for sanding the body;
11) Wire cutters for cutting wires and unnecessary contacts;
12) Compass for drawing circles.

The process of making a homemade active speaker.

Let's prepare two three-watt loudspeakers, a 3.5 mm jack and a PAM 8403 audio amplifier and connect their contacts using connecting wires.

The characteristics of the speakers are written down on the back side, and here they are:

The 3.5 mm connector has three contacts: left channel, right channel and common. There are also four contact plugs: left and right channels, general and microphone; but this speaker doesn’t have a microphone, and why would it, so you don’t have to use a four-pin plug. The values ​​of the plug contacts are shown in the photograph.

We will use an audio amplifier ordered from AliExpress very good quality as stated earlier. This amplifier is powered by a voltage of five volts, so the future speaker can be connected to both a laptop and a phone charger...

We will also use the power button to turn off the speaker.

We take the wires and strip their ends of insulation using a craft pressure for future soldering.

Solder these wires to the audio amplifier using electric soldering iron, but very carefully so as not to spoil or damage the amplifier.

In my case, the blue wire is positive and the brown wire is negative.

We cut off the excess protruding contacts using wire cutters to make it look neater.

We secure the wires together using insulating tape.

It should look like this, as shown in the photo.

Now we solder the power wire to the amplifier with a USB plug. Yes, there will be a wire at the end of the article white, since I resoldered it due to insufficient length, so don’t judge too much.

We strip the USB wires and solder one of the wires using an electric soldering iron to the speaker power switch.

We insulate the wiring using heat shrink.

Now we solder the resulting two wires to the audio amplifier, being sure to observe the polarity: in my case, brown is minus, blue is plus.

Again we bite off the excess on the board with wire cutters.

Here's what I got:

Now we solder a wire with a 3.5 mm plug to the audio amplifier.

The wire must have at least three contacts, but exactly three is better.

We strip the wires and solder them to a 3.5 mm plug.

Now we solder the wires to the audio amplifier, but each wire is in its own place.

According to the colors of the wire, we solder them to the board, namely the black wire is the left channel, which is marked on the board with the letter L; the red wire is the right channel, which is marked on the amplifier with the Latin letter R; and the green wire is the common channel, which is marked on the amplifier accordingly with the Latin letter G.

Now we insulate the 3.5 mm plug with heat shrink and hot glue.

In general, I got it like in the photo.

Now a more complex process begins, namely the preparation of the body.

Drawing a rectangle on plywood, when dividing it in half we get two identical squares, in each of which, in the center of the squares, using a compass, we draw circles of equal diameter for future seats speakers.

Using an electric drill, drill a hole to thread the jigsaw into this hole.

Cut out a rectangle using a hacksaw.

Using a hand jigsaw, cut circles from the rectangular part of the speaker housing.

Three-watt speakers can be easily inserted into the resulting two holes.

And two more rectangular parts of the same size.

For now, we are assembling the body from everything received.

Now you need to attach the audio amplifier to the front of the case.

To do this, we drill a hole using an electric drill, so that the amplifier can be installed freely and securely in this hole.

WITH inside details about drilled hole by using stationery knife We dig out a recess for the amplifier board.

Hello to all DIYers! Somehow passing by construction apartment building, I saw gas workers laying a plastic gas pipe d-225 mm. The idea came to make speaker systems with it. I asked the builders, they cut me 2 pieces with bevels 70 cm long.

I cut out circles (bottom of the speaker) d-225 mm from chipboard, screwed them with black self-tapping screws (8 pcs), and glued them on.

I cut out ovals from 10 mm plywood for the speakers, and also secured them with self-tapping screws.

On the back side of the body of the future speaker system, I drilled holes for clamps for wires.

I puttyed the places where I screwed the screws, sanded the putty spots and the pipe itself, degreased everything with acetone and began gluing the fabric.

Carpet is glued with "Moment" in small areas with tension around the circumference. After gluing the inside of the pipe, I coated the joints with sealant. I soldered the wires to the connector and screwed them to the body, on the other side to the speaker.

I also secured the speaker to the plywood with self-tapping screws and secured the mesh.

That's all - good compact home speakers are ready. Of course, this is not a branded JBL, but with a good amplifier it plays well.

Video - homemade speakers from car speakers

By changing the diameter and length of the body, you can achieve a different sound character. Since it’s difficult to carry out all these calculations initially, just take more to maximize the bass. Bye everyone! I was with you Ivchenko Alexey Novorossiysk.

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