Comparison LG CJ-45 vs LG CM-9960

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).

Radio ranges received by the tuner of the music center. Today, the most common ranges supported are:

— FM. Part of the ultra-short-wave (VHF) range from 87.5 MHz to 108 MHz. Uses frequency modulation, which allows you to broadcast music in stereo with fairly high sound quality, as well as transmit RDS signals (see RDS). At the moment, most music radio stations in the CIS broadcast in this range, as a result of which FM is supported in the vast majority of audio systems. The disadvantage of this option is the limited reception area - a maximum of several dozen kilometers from the transmitter - so FM broadcasts can usually be listened to within one city and its surrounding areas.

— AM (from English amplitude modulation) — radio broadcasting using amplitude modulation. Usually, this term refers to broadcasting on medium waves in the range of 520–1610 kHz; most consumer AM receivers are designed for these same frequencies. The range of AM stations can be hundreds of kilometers, but the sound quality is lower than on FM, so this format is mainly used for talk and news radio stations.

— DAB+. DAB is an abbreviation for Digital Audio Broadcasting, i.e. “digital radio broadcasting”; and “+” means an improved version of this standard. Formally, DAB+ is not only a range, but also a signal transmission format: unlike all the options described above, it is, as the name suggests, digital. This provides a number of advantages over traditional transmitter...s — in particular, a greater range at lower power and high quality of the transmitted sound. In addition, this sound is practically not subject to distortion: weak interference does not affect its quality, and with a critical decrease in transmitter power, the signal is not distorted, but disappears completely. The latter, however, can be written down as a disadvantage; but the only truly significant disadvantage of this option is its low prevalence (so far) in the CIS countries. Technically, such broadcasting can be carried out in any range above 30 MHz, but in practice, several options are used (depending on the country), related to the VHF range. Please note that DAB+ tuners are capable of receiving original DAB radio broadcasts, but not vice versa.

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 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.

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.

— Omnidirectional sound. As the name suggests, audio systems with this feature emit sound evenly in all directions, covering a 360° space. Thus, the device can be installed in the center of the room and evenly “fill” it with sound, which will be clearly perceived at any point. On the other hand, an omnidirectional system usually sounds in 1.0 format (mono); the design may include various tricks to ensure surround sound, but such systems still fall short of full-fledged stereo in most cases.

— Voice assistant. Support of the audio system of the voice assistant. The most popular assistants nowadays are:

• Google Assistant
• Apple Siri
• Amazon Alexa

However, other solutions can also be used. In any case, it is worth noting that we are not talking about the function of the audio system itself, but about compatibility with smartphones, tablets and other gadgets that have their own voice assistants. Thus, to use the voice assistant, you will have to connect the audio system to an external device. On the other hand, the capabilities of such assistants are usually more extensive than those of built-in voice control systems (see below); advanced functions are often supported, such as natural speech recognition with complex queries (“Play the latest album of the band ... that I listened to”), voicing the weather forecast, sports results, etc. Of course, the specific set of supported commands and languages may vary - depending on the voice assistant and its version.

— Voice control. A function that is practically mandatory for smart speakers (see “Purpose”) and is almost never found in other types of audio systems. As the name suggests, this control allows you to control the device using voice commands. It differs from the voice assistant (see the corresponding section) in that in this case we are talking about the simplest commands related to the main functionality of the audio system - for example, “Stop”, “Continue”, “Next track”, etc. It is worth keeping in mind that voice control almost certainly supports English, but the ability to recognize other languages should be clarified separately.

— Mobile application. The ability to control the audio system from a smartphone, tablet or other gadget with a special application installed on it. As a rule, the connection is via Wi-Fi (see "Interfaces"). The convenience of this function is not only that the system can be controlled remotely - the application is often more convenient and provides more options than the controls on the radio itself.

— Multiroom support. The device supports Multiroom technology. This technology allows you to create a single wireless network in your home from several speakers placed in different rooms, and simultaneously play music in all of these rooms. The specific features of such networks may be different in different models, they should be clarified separately. So, some devices use a Bluetooth connection, others - via Wi-Fi (directly or via a local network). In some cases, the control speaker broadcasts sound to all the others, and the same music plays throughout the house, in others, the speakers are "equal", and different tracks can be played simultaneously in different rooms. Some audio systems require an external sound source (smartphone, tablet, etc.), others are capable of playing the role of a player themselves, including for streaming Internet services.

— Karaoke.... A popular entertainment that allows users to sing their favorite songs to a backing track (musical accompaniment with the original vocals cut out) — so that the vocals superimposed on the backing track are reproduced through the acoustics of the audio system. This function requires at least one microphone input.

— Karaoke Mix. An extended version of karaoke (see above), providing various additional options — for example, assessment of performance skills in points, singing competitions, etc. As a rule, it allows you to connect two microphones.

— Internet radio. The ability to listen to Internet radio stations on the audio system. In general, such broadcasting is similar to conventional broadcasting, but it is carried out not via radio, but via the World Wide Web, which provides some additional opportunities. Thus, Internet broadcasting has no restrictions on range and range, allows you to listen to programs from any country and in any language; and the list of broadcasters is extremely extensive, among them there are both traditional radio stations duplicating their broadcasts on the Internet, and specific, purely network projects. The presence of this function assumes support for at least one network interface - Wi-Fi or LAN (see "Interfaces").

— Recording to a USB drive. The ability to operate the audio system in recording mode to an external USB device, such as a flash drive. This allows you to record your favorite radio programs from a regular tuner or Internet station (see above), copy music from optical discs, etc.; specific USB recording capabilities depend on the audio system model.

— Clock. A regular clock is a device for displaying time, most often in the form of numbers on a display. Sometimes it is precisely such a clock that turns out to be the most convenient. In addition, this function is necessary for some other features — primarily an alarm clock (see below).

— Alarm clock. A classic alarm clock that gives a signal at a set time. It can be useful not only for waking up, but also in other cases when it is necessary to warn the user about the onset of a certain time. The peculiarity of this function in audio systems is that the signal can be the switching on of a certain radio station or musical composition.