Comparison Bosch LB2-UC30 vs JBL Control 23

The general specialization of the acoustic system.

Nowadays, this indicator distinguishes home, concert, monitor, information, outdoor and cinema systems, as well as solutions for expanding existing speakers. At the same time, the appointment is not a categorical prescription — many models also allow non-standard use cases. However, it is easier and more convenient to choose a speaker in accordance with the method of application that was originally intended for it. The specific features of acoustics for various purposes are as follows:

— Home. A kind of speaker designed, as the name implies, for individual use at home. Note that the characteristics of such models can be different — from the simplest bookshelf speakers to powerful multi-band speakers designed for home theaters and high-quality audio systems.

— Concert. A distinctive external feature of speakers designed for concerts is their large dimensions and high rated power (in some models it exceeds 1 kW). The latter is indispensable for vast spaces — halls, stadiums, etc. — where the sound must also “shout out” the reaction of the listeners (sometimes quite loud). But it makes no sense to purchase such speakers for home use — not only because of the high cost, but also because instead of hi...gh-level inputs (as in home speakers), such systems have a connector for special equipment, musical instruments, etc. Most often, concert acoustics are sold in 1.0 configurations (see "Number of channels") in the expectation that sound engineers can assemble the desired acoustic configuration from a certain number of components.

— Monitor room. The main purpose of monitor acoustics is sound quality control; accordingly, all such models are distinguished by extremely high accuracy of transmission of all sound details, smooth frequency response and almost complete absence of distortion. This makes them indispensable for professional use (for example, in recording studios): a monitor speaker will allow you to very accurately determine all the shortcomings of the incoming signal, including amplifier noise, audio editing inaccuracies, etc. Like concert systems (see above), such systems are usually equipped with specialized inputs, but it makes no sense to use monitors for home listening for another reason: all sound flaws that are imperceptible on ordinary acoustics will then appear — and can significantly spoil the impression . And the price of such models is very high.

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— Outdoor. Acoustic systems designed for outdoor installation. They can be used, for example, for sound accompaniment of holidays in the country or in nature, playing music in the summer areas of cafes, etc. All models of this type necessarily have a waterproof and corrosion-resistant housing (see "Moisture protection") in case of adverse weather conditions; in addition, they are usually additionally protected from ultraviolet radiation. Outdoor acoustics can be mounted in different ways (see above), however, hanging options are most common.

— Cinema. Models designed, in accordance with the name, for use in cinemas — and not so much in the halls of the "home" format, for 6-10 spectators, but in large-format entertainment complexes for tens and hundreds of seats. Cinema speakers have the following common features. Firstly, they are all made passive, counting on connection to specialized amplifiers; accordingly, high-voltage connectors in the form of terminals or Euroblock sockets are used as inputs. Secondly, the power of such devices is quite high — from 100 W and above. Thirdly, cinema acoustics are usually produced in 1.0 format (see "Number of channels") — in other words, such models are not ready-made acoustic systems, but only separate components from which a specific multi-channel speaker is assembled. This output format makes it possible to accurately select the speakers needed for a particular hall. By type of installation, cinema acoustics usually refers to floor, built-in or wall-mounted. The latter variety is most often designed for installation on the side walls, and the first two are behind the screen. At the same time, floor versions can actually consist of two parts — a classic speaker for low frequencies and a horn for midrange and treble.

— Expansion of the acoustic system. A specific type of acoustics, which initially does not involve independent use and is used as an addition to traditional speakers. Such models are used mainly in multi-channel surround sound systems — to expand the sound stage vertically; they have a characteristic appearance: relatively small dimensions, an inclined top panel and a speaker built into this panel. Thus, the sound from the speakers is directed at an upward angle — in order to be reflected from the ceiling, reach the listener and give the impression that the sound source is from above. The use of "expanding" acoustics allows you to do without the use of specialized ceiling speakers. This is especially convenient in light of the fact that in-ceiling speakers are usually made built-in and rather difficult to install, while expansion modules often allow installation directly on the main speaker components. Also note that this type of acoustics can be initially designed for certain models of the main speakers; this point should be clarified before buying.

— 1.0. Single-channel(monophonic) audio system. "Alone" such speakers do not provide a sense of surround sound, but can be used as separate components for multi-channel surround sound systems.

— 2.0. Normal stereo sound: two speakers responsible for the left and right channels. Allows you to create a minimal illusion of "surround" sound by simulating the displacement of the sound source in the space in front of the listener.

— 2.1. A dual speaker system that creates a minimal illusion of "surround" sound, and a subwoofer that delivers powerful and rich sound by adding bass and ultra-low frequencies.

— 3.0. System of three speakers(centre and two front). According to some manufacturers, such systems in small rooms are capable, with some tricks, of reproducing full surround sound without rear speakers.

— 5.0. A set of five speakers(two front, centre and two rear), which allows you to reproduce a full surround sound, which is subjectively perceived by the listener not only in front, but also behind him.

— 5.1. A set of five speakers and a subwoofer for low and ultra-low frequencies, allowing you to reproduce a full surround sound, which is subjectively perceived by the listener not only in front, but also behind him. 5.1 systems ar...e one of the most popular multi-channel audio formats, widely used, in particular, in home theaters.

There are also much rarer options due to narrow needs:

— 1.1. Systems in the form of a subwoofer, on which a general range speaker is installed on top. They are found mainly in concert acoustics — it is convenient to assemble systems for powerful and rich sound from such components.

— 2.2. Further development of the idea embodied in systems 1.1 (see above); in fact, these are sets of two identical speakers of 1.1 format. Such sets are produced from the considerations that for concerts, especially in relatively small rooms, it is often enough just a pair of 1.1 speakers; it is more convenient and often cheaper to buy two such speakers at once than to buy them one at a time.

— 3.1. A system of three speakers (centre and two front), as well as a subwoofer for bass and ultra-low frequencies. It is a "stripped down" version of the 5.1 system; according to some manufacturers, such systems are capable of reproducing full surround sound in the absence of rear speakers, due to which they are perfect for installation in small rooms where it is not possible to place full-fledged 5.1 acoustics.

— 4.0. A variation of 4.1 systems (see below), devoid of a subwoofer, otherwise completely similar.

— 4.1. Simplified version of 5.1 format (see above); such systems usually lack either a centre or one of the rear channels. Anyway, other things being equal, they are cheaper than full-length 5.1, but their sound quality is significantly lower.

— 4.2. This category includes mainly concert acoustics (see "Intended use"), which is an extended version of the 2.2 described above. In 4.2 systems, not one, but two total range speakers are installed above each subwoofer. Thus, you can achieve better and richer sound.

— 5.2. A variation of the 5.1 described above, supplemented by a second subwoofer — this has a positive effect on the quality and accuracy of bass reproduction. On the other hand, setting up such systems is somewhat more complicated.

— 6.1. Extended version of 5.1 format: two front speakers, a centre speaker, three rear speakers (left, right and centre) and a subwoofer for bass and extra bass. It is characterized by a more accurate transmission of surround sound in the rear sector, but is quite rare.

— 7.0. Extended version of multi-channel audio with five main channels (eg 5.1). In this case, the five main channels are supplemented with two more, which allows to achieve a more voluminous and reliable sound. Most often, additional channels are located at the back ("rear right" and "rear left"), but depending on the specific sound format, other installation options are possible — for example, on the sides of the user.

— 8.1. Systems providing 8 main sound channels plus 1 low frequency. The specific distribution of the main channels may be different, depending on the model. However, all 8.1 systems differ, on the one hand, in good reliability of surround sound, on the other hand, in high cost and complexity in setting up.

Speaker sensitivity.

This characteristic is indicated on the basis of how loud the acoustics are capable of producing when a signal of a certain standard power is applied to it. Simply put, the higher the sensitivity of the speaker, the louder it will sound at the same output power of the amplifier. Thus, sensitive acoustics can be effectively used even in combination with relatively low-power "amplifiers". On the other hand, low sensitivity also has its advantages: it allows you to achieve a more uniform frequency response and reduces the likelihood of overloading the amplifier. In the least sensitive modern speakers, this indicator does not exceed 84 dB, in the most sensitive it is 95 – 96 dB or more.

Note that in fact, you have to pay attention to this parameter when acoustics are planned to be used with a separately selected power amplifier. Therefore, for active systems (see "Type"), sensitivity is purely a reference value, and, usually, it can be ignored when choosing.

The crossover frequency provided in the speaker design.

A crossover is installed exclusively in a multi-band model (see "Number of Bands"). This is an electronic filter that ensures the division of the incoming audio signal into separate frequency ranges and directs each range to "its" set of speakers. And the crossover frequency shows where the boundary between these ranges lies. If there are more than two bands, there will be several such boundaries: for example, for a four-band system it may be specified "0.15 / 0.8 / 2.8 kHz" or "0.12 / 1 / 3.8".

In most cases, this parameter has mainly a reference value: the frequencies of the built-in crossover are selected to match the operating characteristics of the speakers installed in the speaker system.

Rated power of one front speaker. See "Total Power Rating" below for details on power rating. Here we note that the higher the power, the louder the system component can sound — of course, with a properly selected amplifier. In addition, this parameter is very important for matching with the amplifier: it is desirable that the output power on the corresponding amplifier channel be less than the power of the speaker. If the incoming signal is more powerful, distortions in the sound and even damage to the speakers are possible, and if it is weaker, then the sound volume will decrease (in other words, it will not be possible to use the full potential of the acoustics), but this moment will be critical only for listening at maximum volume.

The total rated power of all speaker components, in other words, the sum of the powers of all speakers. As a nominal one, they usually indicate the highest average (rms) power at which acoustics can operate for a long time without overloads and damage. In this case, individual power surges can significantly exceed this value, however, it is the rated power that is the main characteristic of any speaker.

First of all, the sound volume depends on this characteristic: the more powerful the speakers, the louder the sound they can produce if there is a suitable amplifier. In addition, in passive and passive-active models, compatibility with an external amplifier also depends on the power: the output power of the “amplifier” should not exceed the power of the acoustics connected to it, otherwise overloads and even breakdowns are possible.

Detailed recommendations regarding the choice of speakers for power for a particular situation can be found in special sources. However, in general, an indicator of up to 100 W by the standards of modern acoustics is considered quite modest, 100 – 200 W — average, 200 – 300 W — above average, and the most powerful sets give out up to 500 W or even more.

In conclusion, we note two more nuances. Firstly, when comparing different systems according to this ch...aracteristic, one must also take into account the sound format in which they work. In particular, if there is a subwoofer, it can account for a significant part of the total power — up to half or more. As a result, for example, a 2.1 set of 50 W with a 20-watt subwoofer at the main frequencies will not be able to pull out the same volume as a 40-watt 2.0 system: in the first case, each main channel will have only 15 watts, in the second — 20 watts. Secondly, in multichannel systems, the total power can be distributed among the channels in different proportions; so, say, two 5.1 systems with the same total power can differ markedly in front and rear balance at maximum volume.

The total frequency range that the speaker is capable of reproducing. Specified from the bottom of the range in the lowest frequency component to the top of the range in the highest frequency: for example, in a 2.1 system with main speakers at 100 – 22000 Hz and a subwoofer at 20 – 150 Hz, the total value will be 20 – 22000 Hz.

The wider the frequency range — the fuller the reproduced sound, the lower the likelihood that some part of the low or high frequencies will be "cut off". It is worth noting here that the human ear perceives frequencies on average from 16 Hz to 22 kHz, and from a practical point of view, it makes no sense to provide a wider frequency range in speakers. However, quite a few models go beyond this range, sometimes quite significantly (for example, there are speakers with a range of about 10 – 50,000 Hz). Such characteristics are a kind of "side effect" of high-end acoustics, and they are usually given for advertising purposes.

Thus, the lower limit of the range in modern speakers can be within frequencies up to 20 Hz, however, higher values \u200b\u200bare more common — 30 – 40 Hz, 40 – 50 Hz, or even more than 70 Hz. In turn, the upper limit in most modern speakers lies in the range 19 – 22 kHz, although there are deviations both upwards (see above) and downwards.

Various additional features provided in the design of the speaker.

The list of such features may include general design nuances ( bipolar layout, magnetic shielding, horn design, Bi-Amping/Bi-Wiring), special types of emitters ( ribbon, electrostatic), adjustments to improve sound ( HF adjustment, LF adjustment, rotary tweeter), as well as special design elements to improve acoustic characteristics. Regarding the latter, it is worth noting that, in addition to the classic closed design, in our time you can find sound system with phase inverters( front, back or bottom), acoustic labyrinths, passive radiators and with acoustic spikes.

Here is a more detailed description of each of these features:

— Bipolar. Columns of this design have two sets of emitters directed in different directions at an angle to each other (usually about 90° or slightly more). Such sound system are used in some specific c...ases — in particular, bipolar models are considered a good option for the rear channel in a home theater.

— Rotating tweeter. A tweeter is a high-frequency speaker with a rotating design. This feature allows you to change the direction in which the speaker emits sound in the high-frequency range without pivotal the speaker body itself (recall that the correct localization of such sound is quite important for adjusting the sound of the system as a whole). At the same time, there is no particular need to provide this function in free-standing sound system: in such models, as a rule, there are no problems with pivotal the entire body. Therefore, rotating tweeters are found exclusively in built-in speakers (see "Installation") - after all, after installation, such a speaker no longer assumes any movement.

— Magnetic shielding. In speakers with this feature, the housings are supplemented with special materials that are impermeable to magnetic fields. Thanks to this, the powerful magnets that are usually equipped with speakers in modern speakers have virtually no effect on surrounding devices. This is especially important when used near sensitive electronics: plasma panels, high-end amplifiers and receivers, etc.

— Phase inverter. A device in the form of a characteristic tube installed in the speaker body with an outlet into the surrounding space. The phase inverter (PI) increases the sound pressure and improves the sound of the speakers in comparison with similar closed-type sound system ; this is especially noticeable at low frequencies. True, the movement of air in the tube can create additional noise; however, most models use various tricks designed to compensate for this phenomenon. But the clear disadvantage of such equipment is the increase in the overall dimensions of the speaker. We emphasize that this function should not be confused with the acoustic labyrinth (see below) - the PI is made straight and has a relatively short length.
It should also be noted that the phase inverter can be installed in different ways: most often in the front, less often in the back, in some models - below, and extremely rarely - on top or on the side. And in some speakers, two phase inverters are installed at once, with different locations. These details are not indicated in the specifications, since they can be easily determined from the photographs. From an sound system point of view, it is impossible to say for sure which location is better - each option has its supporters and opponents, especially since the issue of sound quality is largely subjective. But from a purely practical point of view, the front phase inverter is the most convenient: it allows you to place the speakers even close to the wall. With a rear location, the speaker system should be at least 3 - 4 cm from the wall, and ideally - not less than the diameter of the phase inverter. The third popular option - bottom installation - is found in some models of shelf and floor-standing speakers equipped with stands of the appropriate height, as well as in suspended models designed for a large amount of free space under the speaker.

— Acoustic labyrinth. Another device used to improve the richness and overall quality of sound. In some ways similar to the phase inverter described on top — it is also an air duct of a strictly selected length, connecting the internal volume of the speaker with the external space. The key difference is that in this case the air duct is not made straight, but in the form of a “snake” with many bends (hence the name “labyrinth”). The walls of the labyrinth are covered with special materials that absorb sounds. Such a design has a number of advantages over traditional bass reflexes. Thus, the speakers are more compact; with the same dimensions of the case, the labyrinth has a greater effective length, which has a positive effect on the power and richness of low frequencies; and the winding air duct is almost not susceptible to the occurrence of extraneous sounds (unlike phase inverters, where the design must be calculated very accurately to dampen such sounds). On the other hand, labyrinths are noticeably more complex and, accordingly, more expensive, and therefore are less common.

— Treble control. A control that allows you to adjust the sound level of high frequencies separately from the rest of the range. Due to this, you can change the color of the sound to a certain extent, without resorting to external equalizers and other complex devices. This function can be combined with bass control (see below), but there are also many speakers where only high frequencies are adjusted.

— Low frequency control. A control that allows you to adjust the sound level of low frequencies separately from the rest of the range. Like the HF control described on top, it allows you to change the sound color to a certain extent without resorting to external equalizers and other complex devices. However, this function is very rarely used without a high frequency control (although there are such speakers).

— Ribbon driver. A ribbon driver installed in one or more speakers of a speaker system; for a number of reasons, this design is used mainly in high-frequency tweeters. The difference between such devices and traditional drivers is that in this case, a metal ribbon is installed between the poles of the magnet instead of a traditional coil (hence the name). This provides a number of advantages: high sensitivity, minimal distortion, wide horizontal coverage. The main disadvantages of the ribbon design are its high cost and poor suitability for low frequencies.

— Electrostatic emitter. An electrostatic emitter installed in one or more speakers of the speaker system. The design of such a device is based on a thin and light membrane fixed between two stator grilles — a signal is fed to the bottom, and the membrane vibrates with an electric field. In this way, you can achieve very reliable, clear sound, with a minimum of nonlinear distortion. At the same time, electrostatic emitters are effective mainly at mid-high and high frequencies, so for effective operation, the speaker system inevitably has to be supplemented with traditional speakers. Among the clear disadvantages of such equipment, we can note the large dimensions, high cost and specific requirements for amplifiers: an emitter of this type requires a high-class "amplifier", necessarily with an output transformer. Therefore, this function is rare - in some premium speakers.

— Horn design. The presence of speakers in the speaker system built according to the horn scheme. Such a speaker has the form of a characteristic bell, in the depth of which there is a radiator. Due to the narrow directivity and specific influence on the propagation of sound waves, horns improve the efficiency of sound transmission in a fairly wide frequency range. In fact, it can be said that the presence of a horn increases the sensitivity of the speaker system. For a number of reasons, it turned out that the horn design of the main speaker is used mainly in information speakers (see purpose), while in other cases this form is provided for a high-frequency speaker (twitter).

— Passive radiator. The presence of a passive radiator in at least one speaker of the AC system. Such a device can be described as a low-frequency speaker from which the coil and magnet have been removed, leaving only the outer membrane of the radiator. This membrane oscillates due to sound waves created by conventional speakers and acts as a resonator that amplifies the sound of low frequencies. In this regard, a passive radiator is similar to a phase inverter and an acoustic labyrinth (see on top); however, unlike a bass reflex, it is almost not subject to the occurrence of extraneous noise, and is significantly cheaper than a labyrinth. On the other hand, an additional radiator on the front panel significantly increases the dimensions of the speaker — usually in height.

— IMAX Enhanced. The IMAX Enhanced certification mark is assigned to equipment that meets the audio device certification requirements of IMAX Corporation. In combination with DTS audio technology, it provides the signature sound “like in IMAX cinemas” at home. The most accurate reproduction of such audio is possible in systems with a large number of channels (from 5.1 and more). Note that for the effect of full immersion, IMAX Enhanced certification must also apply to video equipment for content playback (TV, projector, etc.).

— Bi-Amping/Bi-Wiring. The ability to operate sound system in the Bi-Amping or Bi-Wiring format. Models with this feature are multi-band (see "Number of bands") and have not one, but two sets of terminals for each speaker - for low and high frequencies. This allows the use of the on top-mentioned connection methods. Thus, when working in the Bi-Wiring format, each contact at the output of the power amplifier is connected with two separate wires to two terminals on the corresponding speaker at once: for example, the positive contact of the left channel - to the positive contacts of the low-frequency and high-frequency inputs on the left speaker, the negative - to the corresponding negative contacts, etc. This improves the frequency response: due to the division into separate cables, the low-frequency signal does not "steal energy" from the rest of the range, and each band receives enough power for the effective operation of the corresponding speakers. In the Bi-Amping format, two separate amplifiers are used, each with two pairs of contacts at the output - as a result, each speaker terminal is connected strictly to "its" contact. This connection method is not cheap, but it allows you to achieve even greater purity of sound and uniformity of frequency response; Bi-Amping is considered the ideal option for tech who do not accept compromises in matters of sound quality.

— Acoustic spikes. Supports of a special shape, used mainly in floor-standing speakers. In accordance with the name, such supports are made pointed, and it is the sharp ends that rest on the floor; special small plates are usually used to protect the floor from damage. In any case, the point of such a design is to minimize the area of contact between the speaker and the surface underneath it. This, in turn, increases the pressure at the contact points and minimizes the so-called parasitic vibrations — vibrations transmitted from the speaker to the floor. Acoustic spikes are considered an almost mandatory element of equipment for Hi-Fi class floor-standing speakers — without such equipment, the aforementioned parasitic vibrations can irreparably spoil the sound of high-class speakers and negate all their advantages. Note that speaker spikes are also sold separately; however, buying speakers initially equipped with such stands is often easier than looking for third-party accessories.

The diameter of the woofer or combined woofer/midrange speaker(s). The larger the speaker, the lower its operating frequencies and the more sound power it can provide. Therefore, you should pay special attention to this parameter if you want to get high-quality rich bass - especially if we are talking about an audio system without a subwoofer. More detailed information about speaker sizes can be found in special sources.