Comparison LG OJ-98 vs Sony CMT-SBT40D

- Music Center. Music centers are stationary audio systems, including a player, amplifier and acoustics; Their distinctive feature is the speakers, made separately from the main unit. Some models may provide mounts for installing speakers on the main unit, but these mounts are quick-release, and the length of the wires allows you to place the speakers separately.

- Minisystem. Minisystems are relatively small devices made in one-piece housings; Despite their small size, they are usually designed for stationary use, although they may have independent power supplies (see below). The functionality of mini-systems can be different: some models, in fact, are speakers with slightly expanded capabilities, in others these capabilities can be comparable to full-fledged music centers and even have wireless charging.

— Radio tape recorder. The radios have a distinctive design reminiscent of cassette recorders; and some of them are even capable of working with cassettes, see "Media". Like the music centers described above, such devices have everything you need for listening - a player, an amplifier and acoustics; however, the speakers are made non-removable, and the functionality of radio tape recorders is usually more modest. On the other hand, such models are portable and can even be used to play music on the go - almost mandatory f...eatures of radio tape recorders are the presence of a handle for transportation and the ability to be autonomously powered (see below) from replaceable batteries.

— Floor system. The purpose of audio systems of this type is already clear from the name: they are initially designed for installation on the floor. This installation allows you to create fairly large devices with powerful acoustics; in fact, most floor-standing audio systems are actually a set of speakers with a built-in player. However, there are also quite compact models of this type that allow desktop or wall installation with the stand disconnected.

- For parties. Audio systems for organizing incendiary musical parties with friends and family. Such models are capable of sounding a vast space both indoors and on the street dance floor. Often, audio systems for parties are complemented by built-in lighting effects to create a disco atmosphere; microphones can also be connected to them, which karaoke lovers will appreciate. Alternative names for such audio systems are Party speaker or PartyBox.

— For musicians. Advanced speakers without light and music with good sound quality, especially for musicians who give performances on the street or participate in outdoor events. Such models are not intended for full-fledged concerts, but rather for “live” performances in public places. Audio systems often include the ability to connect musical instruments, and they are often equipped with a suitcase-type handle for ease of carrying the equipment. If it falls under the above, but there are lighting effects - For parties.

— Smart speaker. Audio systems in the form of relatively small single speakers with “smart” control electronics. For such devices, four key features can be distinguished: Internet connection (usually via Wi-Fi), synchronization with a smartphone or tablet (usually the same), support for voice commands and advanced functionality. In fact, smart speakers are not classic audio systems, but universal “assistants” with speakers for playing music; and the voice control capabilities in them go far beyond the “musical” functions. Thus, many models allow you to set a timer or alarm on a smartphone, control smart home components, receive help on a variety of requests, etc. At the same time, contextual recognition of commands is often supported, with the ability to process complex requests like “put on the band I listened to yesterday In the evening".

The maximum number of audio channels that the audio system can reproduce through its own acoustics.

— 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.

— 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.

— 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.

— 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).

Tuner support for Radio Data System technology. This technology is used mainly in the FM band; it allows, in addition to the sound signal, to transmit additional textual information by radio — for example, the names of broadcast compositions, announcements, advertising messages, etc. For RDS-enabled audio systems, this information is shown on the display.

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.

Nominal sound power (see "System power") on each of the main channels of the audio system. This indicator is most often indicated in models with a subwoofer (see "Number of channels"); knowing it, you can estimate the power distribution between the main speakers and the subwoofer.

The subwoofer power rating is a bass driver used in 2.1 and 3.1 systems (see "Number of Channels"). For rated power in general, see "System Power"; and in the case of a subwoofer, this indicator allows you to evaluate the volume and richness of the bass produced by the audio system, as well as the ratio between the power of the main channels and the “subwoofer”).

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.

The phase inverter is a tube installed in the column housing and having an outlet to the surrounding space. The length of the tube is chosen so that a signal comes out of the outlet, inverted in phase relative to the signal from the front of the diffuser. This enhances the sound pressure and improves the sound of the speakers, including at low frequencies. Note that such audio systems should be placed at a certain distance from walls, furniture, etc. — otherwise, a hum may occur due to the movement of air through the phase inverter tube.

A similar function in some models is performed by a passive radiator (see below).

- 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.

- 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.

- 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.