Number of channels
The maximum number of audio channels that the audio system can reproduce through its own acoustics.
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1.0. One channel of audio allows only monophonic sound — enough to hear the sound, but not providing a surround effect. The advantage of this option is compactness, because For normal operation, it is enough to equip the device with one speaker. The single-channel format is found mainly in inexpensive models, as well as in the most compact audio systems, where small size is more important than "fancy" sound.
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2.0. Two channels is the minimum required to play stereo sound. This format already allows you to achieve a sense of spaciousness without requiring too many speakers and complicating the entire system. Therefore, he is very popular.
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2.1. Modification of the 2.0 format described above,
supplemented by a subwoofer — a specialized speaker for low frequencies. The use of a subwoofer improves sound quality by delivering rich bass sound.
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2.2. A further extension of the 2.1 format described above, providing for the presence of two subwoofers — this improves the reliability of the transmission of low frequencies.
— 3.1. An extended version of the 2.1 standard, in which two classic stereo speakers are complemented not only by a subwoofer, but also by a thi
...rd, centre speaker. This allows you to improve the sound quality — in particular, due to a richer surround sound.
Note that 2.0 models that do not have their own subwoofer may be equipped with a subwoofer output (see below).System power
The total sound power provided by the audio system at maximum volume, in other words, the total power of all the speakers provided by the device (including the subwoofer).
The higher the power, the louder the system will sound and the larger the area it can cover. On the other hand,
high power significantly affects the price, dimensions, weight and power consumption of the device. In addition, when evaluating and comparing according to this indicator, it is worth considering some nuances. Firstly, some manufacturers go to the trick and give in the characteristics not the average, but the peak sound power; such numbers can be quite impressive, but they have very little to do with real loudness. So if it seems to you that the claimed power is too high, it's ok to clarify what exactly is meant in this case. Secondly, when comparing, it is worth considering the presence of a subwoofer — it plays an auxiliary role, but it can account for more than half of the total system power. Because of this, for equal total power, a device with a subwoofer may be quieter than a model without a subwoofer: for example, a 2.0 40W system will have 20W per main channel, while a 2.1 40W model may have 20W per subwoofer, and only 10 watts for the main speakers.
Number of bands
The number of distinct frequency ranges (bands) into which sound is divided when played through the acoustics of an audio system. For each such band, a separate speaker is provided, and sometimes several.
The simplest option provides 1 lane; it is very popular in modern audio systems, because. requires a minimum number of speakers, and the sound quality can be quite good. More advanced options provide 2-3 bands (low and high frequencies, or bass, treble and medium), and in high-end models, the number of bands can be up to five. Note that, in addition to integers, models are also produced with a fractional number of stripes — for example, 2.5 or 3.5. This marking indicates the presence in the design of a speaker responsible for two bands at once: for example, model 2.5 has separate speakers for bass and treble plus a combined bass + midrange (similar in design to bass, but also loaded with mid frequencies).
Anyway, the abundance of bands, usually, indicates a high class of acoustics: the more separate frequency ranges, the narrower the specialization of each speaker, the more accurately it is able to reproduce its part of the signal, and the more complex the system is.
Sensitivity
Sensitivity determines the intensity of the acoustics response to a signal of a certain level; Simply put, the higher this figure, the higher the volume of the speaker system will be at the same signal level. Note that in the case of audio systems, this parameter plays a secondary role: it is important for selecting acoustics for an amplifier, and here both of these components are in most cases optimally matched by the manufacturer to each other.
Frequency range
The total frequency range reproduced by the acoustics of an audio system. Measured from the lower threshold of the lowest frequency speaker to the upper threshold of 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.
In general, the wider the frequency range, the fuller the reproduced sound will be, the less low and high frequencies will be lost due to insufficient acoustic capabilities. On the other hand, do not forget that the actual sound quality also depends on a number of other parameters — primarily the frequency response. In addition, human audible frequencies range from 16 Hz to 22 kHz; deviations from these values are very small, and the upper limit also decreases with age. Therefore, from a practical point of view, it does not make sense to provide too large a frequency range; and impressive performances like 10 – 50000 Hz, found in top-class models, are usually more of a kind of "side effect" of high-quality speakers (and at the same time — a marketing ploy) than a really significant moment.
Interfaces
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AirPlay. AirPlay technology was developed by Apple. It is based on Wi-Fi and is used to wirelessly broadcast content from Apple devices to external audio systems. Thus, this function is useful for tech who want to connect an iPhone or iPod touch to the audio system, but do not want to bother with wires; However, it is possible to connect other devices via AirPlay - for example, a PC with iTunes and a Wi-Fi module installed.
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AirPlay 2. The second generation of the AirPlay technology described above, introduced in 2018. Among the main innovations of this version is support for the multiroom format, that is, the simultaneous broadcast of several audio signals to different compatible devices installed in different places. In this way, you can, for example, turn on a radio broadcast of a news program in the living room, relaxing music in the bedroom, etc. In addition, AirPlay 2 received a number of other improvements - improved buffering, the ability to stream to stereo speakers, as well as support for voice control via Siri.
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Chromecast. Original name: Google Cast. Technology for broadcasting content to external devices, developed by Google. Allows you to transmit an audio signal from a PC or mobile device to the audio system; the broadcast is usually carried out via Wi-Fi, while the receiver and the signal source must be on the same Wi-Fi network (with t
...he exception of Chromecast media players). Note that in signal sources (smartphones, tablets, PCs, etc.) Chromecast is implemented at the level of individual applications. For example, at the time of its creation, this feature was available, in particular, in the YouTube and Netflix applications for Android and iOS, as well as in the web versions of these applications for Chrome. Thanks to this format, this technology is extremely widespread these days, and the ability to connect a particular gadget to an audio system with Chromecast is usually limited to the ability to install appropriate applications on this gadget.
- DLNA. DLNA (Digital Living Network Alliance) is a standard that allows you to combine various types of home electronics and household appliances into a single network for content exchange and control. In the case of audio systems, DLNA can be used, for example, to play music from the disk of a computer connected to such a network, broadcast sound to a device installed in another room (for example, an amplifier), etc. Connecting to DLNA can be done either wired or wirelessly (using the Wi-Fi standard), and device compatibility does not depend on their manufacturers - the only condition is compliance with the DLNA standard.
- LAN. Standard interface for wired communication to local computer networks based on the RJ-45 connector. Its presence allows you to use various network functions, such as Internet radio (see "Advanced") or DLNA (see above). Compared to another network interface - Wi-Fi - LAN is less convenient due to the presence of wires, but is more reliable and provides a higher actual data transfer speed.
- Wi-Fi. The presence of a Wi-Fi wireless communication module in the audio system design. This technology is used both in computer networks and for directly connecting various devices to each other; its “range” is sufficient to work within residential premises, even through walls. In this case, Wi-Fi can be used to work with network functions such as Internet radio or DLNA(see above). Moreover, this option is more convenient than a wired LAN due to the absence of actual wires. In addition, support for this technology is a prerequisite for using the AirPlay and Chromecast functions (see above); and in some devices, Wi-Fi even allows you to connect smartphones, tablets and other gadgets as remote controls.
One of the most modern and fastest standards of this wireless communication technology is Wi-Fi 5. The 802.11ac version uses the 5 GHz band (less congested and more noise-resistant than 2.4 GHz), providing speeds of up to 1.69 Gbps per antenna and up to 6.77 Gbps with multiple antennas.
— Bluetooth. Direct wireless communication technology between various devices. One of the most popular ways to use Bluetooth in audio systems is to work with an audio signal, primarily broadcasting sound to wireless headphones or speakers; and some models also provide the ability to connect a smartphone, tablet or other device and use the audio system as an external Bluetooth speaker. However, it is worth considering that initially Bluetooth is noticeably inferior to a wired communication in terms of sound quality; however, in our time, this disadvantage is often compensated by the use of one or another version of the aptX codec(see below).
In addition, other options for using Bluetooth may be provided - for example, exchanging files between the built-in memory and the same smartphone, or remote control via an application. They are not mandatory for modern audio systems, but with the development of technology they are becoming increasingly widespread.
In modern audio systems, the Bluetooth v 5 standard is most often used. Its important innovation is the expansion of the capabilities of the BLE (Bluetooth Low Energy) mode: if necessary, the device can increase the range by reducing the speed, or speed up transmission at the cost of reducing the range. In addition, a number of improvements have been introduced regarding simultaneous work with multiple connected devices.
- aptX support. The audio system supports aptX, a codec designed to improve the quality of sound transmitted via Bluetooth. Accordingly, this function automatically means the presence of a built-in Bluetooth module (see above). The need to use special technologies is due to the fact that in the original Bluetooth format the audio signal is very highly compressed, which significantly affects the final sound quality. The aptX technology is designed to correct the situation: according to the creators, it provides sound purity “comparable to Audio CD (16-bit/44.1kHz)” and almost as good as a wired communication. This is often enough even for comfortable listening to lossless formats, not to mention MP3 and other popular compressed formats. Of course, to use aptX, the signal source must also support it.
- aptX HD support. Audio system support for the aptX HD codec - an improved and updated version of the aptX described above. This version claims sound purity comparable to Hi-Res audio materials (24-bit/48kHz); this allows you to comfortably listen not only to MP3, but also to lossless formats and even uncompressed audio materials. On the other hand, aptX HD support is quite expensive, and its advantages over the original aptX only become noticeable on very high-quality audio materials, for which consumer audio systems are rarely used. Therefore, this function is not particularly widespread.
- A.A.C. A codec used primarily in Apple portable devices to improve sound transmitted via Bluetooth. In this sense, it is similar to aptX (see the corresponding paragraphs), but is noticeably inferior to it in terms of capabilities: if the sound of aptX is compared with Audio CD, then AAC is at the level of an average quality MP3 file. However, for listening to the same MP3s, this is quite enough; the difference becomes noticeable only on more advanced formats.
-LDAC. Sony's proprietary Bluetooth codec. It surpasses even aptX HD in terms of bandwidth and potential sound quality, providing performance at the Hi-Res level of 24-bit/96kHz audio; there is even an opinion that this is the maximum quality that it makes sense to provide in wireless headphones - further improvement will simply be imperceptible to the human ear.
— Network streaming audio. The ability of the audio system to work with network streaming audio services such as Deezer, Spotify, Tidal, etc. Such services are designed to broadcast content (in this case, mainly music) over the Internet; in this case, the played files are not saved in the audio system, but are played directly from the corresponding resource on the World Wide Web. Nowadays, there are many streaming services that differ in the range of music and access conditions; The specific list of supported services should be clarified separately. However, in any case, the main advantages of online streaming include an extensive selection of content and almost instant access to the desired composition; Some services can also work like a radio, automatically selecting music according to the producer's preferences.
- Speakerphone. Possibility of using the device as a hands-free system for a mobile phone. In this mode, the audio system connects to the device, most often using Bluetooth (see above), and the voice of the subscriber on the other end of the line is output not to the phone, but to the speakers of the audio system. This is often more convenient than holding the phone to your ear; In addition, speakerphone is useful if several people need to participate in a conversation.
— NFC chip. NFC is a short-range wireless technology (about 10 cm). In audio systems, NFC is used primarily to facilitate communication via Wi-Fi or Bluetooth (see above). With this chip, you can simply bring an external NFC-compatible device to the audio system and confirm the communication - it's easier than manually adjusting settings.Inputs
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RCA. The RCA interface uses coaxial cables with characteristic tulip plugs and corresponding connectors. It can be used to transmit different types of data, but in this case it is meant to connect an audio signal from a preamplifier in analog format, one audio channel per connector. RCA is widely used in modern audio equipment, but its resistance to interference is very modest.
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Mini-Jack(3.5 mm). Standard connector for most modern portable audio equipment. In audio systems, it is mainly used to connect such equipment — primarily pocket media players. It uses analog signal transmission, but its resistance to interference, like that of RCA, is low, and the quality may be even lower due to the fact that both stereo sound channels are transmitted via one cable.
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Coaxial S/P-DIF. An electrical variation of the S/P-DIF standard that uses a coaxial cable with a tulip connector to transmit the signal. This interface should not be confused with the analog RCA described above — despite the identity of the connectors, these standards are fundamentally different: “coaxial” operates in digital format and allows for the transmission of even multi-channel sound over a single cable. Compared to optical S/P-DIF, this interface is less resistant to interference, but more reliable, since the electrical cables are not as delicate.
— Optical. One of the varie
...ties of the S/P-DIF standard — along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fiber-optic cable. The main advantage of this interface is its complete insensitivity to electrical interference, while its capabilities are sufficient even for working with multi-channel sound. Among the disadvantages, it is worth noting the high price of connecting cables, as well as the need for careful handling of them.
— For microphone. Input for connecting a microphone to an audio system; can use different types of connectors (3.5 mm mini-Jack, 6.35 mm Jack, etc.). This function is mandatory for models with karaoke (see "Additional"), but can also be used for other purposes.
— Instrumental. Connectors used to connect musical instruments (acoustic or bass guitars, keyboards, etc.). Most often, they are made in the form of 6.35 mm Jack sockets. The audio signal from the pickups has its own specifics, so the instrument input is usually characterized by a higher input signal level and special impedance matching to ensure optimal sound quality.Outputs
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RCA. The RCA interface uses coaxial cables, with characteristic "tulip" plugs, and the corresponding connectors. It can be used to transfer different types of data, however, in this case, it means outputting an audio signal in analogue format, one channel of audio per connector. RCA is widely used in modern audio technology, but its resistance to interference is very limited.
— Mini-Jack (3.5 mm). One of the standard connectors in modern audio equipment, it is widely used in portable devices, as well as for connecting headphones. However, we note that in this case we mean the jack responsible for the line output — an interface for transmitting an audio signal in analogue format to an external device, such as an amplifier. The headphone jack is listed separately in our catalog, even if it belongs to the 3.5 mm mini-Jack standard; See below for details on headphone output.
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Coaxial S / P-DIF. An electrical version of the S / P-DIF standard, using a coaxial cable with a “tulip” connector for signal transmission. Do not confuse this interface with the analogue RCA described above — despite the identity of the connectors, these standards are fundamentally different: "coaxial" works in digital format and even multi-channel audio can be transmitted over a single cable. Compared to
optical S/P-DIF, this interface is less resistant to interference, but more rel
...iable because electrical cables are not as delicate.
— Optical. One of the varieties of the S / P-DIF standard is, along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fiber optic cable. The main advantage of this interface is its complete insensitivity to electrical interference, while its capabilities are sufficient even to work with multi-channel audio. Among the shortcomings, it is worth noting the high price of connecting cables, as well as the need for careful handling of them.
— Subwoofer. A separate output for connecting an external subwoofer — a specialized low-frequency speaker. The use of such a speaker allows you to significantly improve the sound of low frequencies, make the bass powerful and rich, which general-purpose speakers are not capable of. Note that such an output can also be useful in systems with a built-in subwoofer — external "subwoofers" are in most cases more powerful and provide more options for adjusting the sound.
— Headphones. Separate headphone output. Most often, a standard 3.5 mm mini-Jack or 6.35 Jack is used for this purpose, but there may be other options — for example, a manufacturer's proprietary connector. Anyway, headphones can come in handy in situations where you need to keep quiet — for example, if you want to listen to music at a late time when others are already sleeping — or vice versa, in noisy environments when ambient sounds drown out the speakers of the audio system.
— Composite. The full-size composite interface includes three connectors — one for video transmission and two for left and right stereo channels. However, in this case, a composite output usually means only a video connector (the standard acoustics of the audio system are responsible for the sound, it usually makes no sense to broadcast it to a TV). Anyway, this output allows you to connect the audio system not only to the latest, but also to frankly outdated TVs. Its disadvantages are poor image quality and incompatibility with HD.
— Component. Output for transmitting video signal in analogue format. Outwardly similar to the composite interface described above, because also uses three RCA cables; however, in this case, these cables carry three components of the video signal (hence the name). The component interface is considered the most advanced among the popular analogue video standards, it provides the highest image quality among them and is even capable of working with HD resolutions. Among the shortcomings, it is worth noting the impossibility of transmitting sound — this will require a separate connection.
— S video. Analogue interface for video transmission. In some way similar to the component described above, since it also provides separate wires for transmitting video signal components; however, in this case there are only two of these wires. This, on the one hand, allowed us to limit ourselves to one connector instead of several, on the other hand, it slightly reduced the quality of the “picture” and limited the bandwidth, so HD is out of the question with such a connection.
— SCART. Universal audio/video interface using a characteristic large 21-pin connector (20 pins plus a rim around the connector). For a long time it was the standard for European video equipment, but today it is considered obsolete due to its low bandwidth and significant dimensions. Note that SCART can work with signals of different formats, which allows the use of adapters — in particular, for connecting external devices via composite and component interfaces.
— HDMI. Universal digital interface that allows you to transfer HD-video and multi-channel audio over a single cable. It is practically a standard for modern video equipment, in particular, it is present in most TVs. In audio systems, this type of output is used in the same way as the coaxial S / P-DIF described above — that is, to output the audio signal in digital form.Autonomous power supply
Type of
independent power sourceused in the audio system. Such power is usually not the only option — it only complements the ability to work from the network.
— AA batteries. Replaceable elements of a standard size, colloquially known as "finger". Available in a variety of options, varying in quality and price, available not only as disposable batteries, but also as rechargeable batteries; sold almost everywhere. The main advantage of all replaceable cells is the ability to quickly change dead batteries for fresh ones (of course, if there is a reserve), while the original battery has to be charged — and this takes time and an external power source. As for AA, they have a relatively low power and capacity. These characteristics are sufficient for relatively compact devices; however, for models that need to power mechanical drives (for example, for CDs) and/or provide high sound power, “AA” batteries are poorly suited, and therefore are rarely used in them.
— AAA batteries. Replaceable elements, known as "mini-finger" or "little fingers". In general, they are similar to the AAs described above and differ from them only in small sizes and, as a result, less power. Because of this, such power is used only in the most compact models of audio systems, which do not require high power, but small sizes are crucial.
— Batteries C. Replaceable cells known as "Baby". The features of replaceable cells are generally desc
...ribed in AA Batteries above; here we note that C batteries have a cylindrical shape and are similar in length to “finger-type” batteries, but are much thicker, due to which they are distinguished by higher power and can be used in rather “gluttonous” systems.
— D batteries. Replacement cells, the largest variety of standard cylindrical batteries used in modern audio systems. Used in the most powerful models that require a large amount of energy.
— Batteries. This parameter is indicated in our catalog in two cases: if the device uses standard replaceable elements that do not belong to any of the standard sizes described above, or if the battery size is not indicated in the manufacturer's official data.
— Accumulator. Powered by its own original battery, which is not related to standard sizes, and in some models is also non-removable. On the one hand, this option eliminates the need to constantly buy replacement batteries (or significantly spend money once on rechargeable batteries), moreover, the battery is usually supplied as a kit. However, when the charge is exhausted, in most cases the only option is to charge from an external power source — and this requires not only the presence of such a source, but also a fairly large amount of time.