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.
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.
Inputs
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RCA. The RCA interface uses coaxial cables with characteristic "tulip" plugs and corresponding connectors. It can be used to transfer different types of data, however, in this case, it means connecting the audio signal from the preamplifier 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.
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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 analogue signal transmission, while the resistance to interference, like RCA, is not high, and the quality may even be lower due to the fact that both channels of stereo sound are transmitted over the same cable.
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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 reliable because electrical cables are not as delicate.
— Optical. One of the va
...rieties of the S / P-DIF standard is, along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fibre 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.
— Under the 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 "Advanced"), but can 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 format sockets. The audio signal from pickups has its own specific characteristics, so the instrument input typically features a higher input level and special impedance matching to ensure optimal sound quality.
