The range of audio frequencies supported by acoustics. The wider this range — the fuller the reproduced sound, the lower the likelihood that some of these details at low or high frequencies will remain “behind the scenes”. At the same time, the human ear is able to hear frequencies of the order of 16 – 22,000 Hz, and with age, this range narrows even more. In modern audio equipment, especially at the top level, there may be more extensive ranges, but from a practical point of view, this does not make much sense. In addition, it is worth noting that a wide frequency range in itself does not guarantee high-quality sound — a lot also depends on the frequency response.
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Bluetooth. A technology used to wirelessly connect various devices. Allows you to transmit an audio signal, for this purpose it is most often used in computer speakers. This feature is especially convenient when using speakers with equipment that has its own Bluetooth modules — primarily with laptops and monoblocks; it is also possible to connect to compact gadgets like a smartphone or tablet (although it is usually more convenient to use specialized self-powered speakers with such devices). And for computers that do not have Bluetooth, separately connected adapters are available. The range of such a connection is at least several metres; the convenience of the lack of extra wires is obvious. However note that a regular Bluetooth connection compresses the sound quite strongly and may degrade its quality. Therefore, if this moment is critical for you, you should choose speakers with support for one of the aptX options or with a higher Bluetooth version. Each next "generation" has additional features.
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Support for aptX. A feature found in Bluetooth speakers (see above). The aptX codec is used to improve the quality of audio transmitted over such a connection; according to the creators, it allows you to achieve quality comparable to Audio CD (16-bit/44.1kHz). Thus, if a regular Bluetooth connection can significantly degrade the sound of even MP3 files with a decent bitrate (not to mention lossless
...formats), then when using this codec, the sound quality is often limited not by the properties of the channel, but by the properties of the source file and the acoustics itself . Of course, for aptX to work, it must be supported not only by the speakers, but also by the signal source.
— Support for aptX HD. Support for the aptX HD codec, an updated version of the original aptX (see above). This standard achieves sound clarity comparable to Hi-Res (24-bit/48kHz) audio. On the other hand, its support is more expensive; and the differences from the original aptX only become noticeable on very high-quality audio materials, for which computer speakers are rarely used. Therefore, this function has not received much distribution.
— NFC. Technically, NFC is a universal wireless technology with a range of up to 10 cm, which allows to achieve a very wide range of applications. However, in computer speakers, this technology is mainly used to speed up Bluetooth connection (see above): it is enough to bring another NFC device (for example, a smartphone) to the speaker chip — and the chips will “recognize” each other and automatically set up the connection, the user will only have to confirm his.
— USB A. USB port, which allows you to connect external peripheral devices to the speakers — primarily drives like "flash drives". Most often, such a connection is used to play music from external drives — in other words, the presence of USB A turns the speakers into a standalone music centre. Often, it is also possible to charge portable gadgets (for example, smartphones) from this port. On the other hand, note that speakers with this feature are noticeably more expensive than similar models without USB, and they may be inferior in sound quality due to the presence of additional electronics that can interfere.
— Card Reader. Own device for reading memory cards, most often the SD standard. Speakers with a card reader can work like a stand-alone music centre: music from a memory card can be played even without a computer. At the same time, the card reader itself is used only by speakers; the ability to read a memory card by a computer is usually not provided in such models. It is also worth bearing in mind that the memory card slot and the electronics that “serve” it are a potential source of interference, so speakers with this function may be inferior in sound quality to counterparts without a card reader (at a higher cost).
— FM receiver. The presence of a built-in FM tuner allows you to use the speaker system as a radio receiver — to receive and play FM radio broadcasts. It should be noted that for reliable reception, most likely, an external antenna will be required; a cable for connecting it is sometimes included, but the antenna itself must be purchased separately.
— Treble adjustment. The ability to separately change the volume of high frequencies. In fact, it is the most simplified version of the equalizer: it allows you to adjust the overall colour of the sound by changing the HF level relative to the rest of the frequency spectrum. Most often used in combination with bass control (see below), but can also be provided as the only frequency control.
— Bass adjustment. The ability to separately change the volume of high frequencies. Similar to the treble control described above, used to adjust the overall tone of the sound. At the same time, quite a few models with this function have only a LF control (without a HF control). But do not confuse this function with subwoofer level control. In this case, it is precisely the adjustment of the lower frequencies of the entire system that is implied.—
mini-Jack (3.5 mm). The 3.5 mm jack is used as a standard analogue audio output in almost all modern PCs and laptops; in addition, it is installed in most smartphones, tablets and pocket players, and in many other types of technology is very common. Thus, most modern computer speakers are equipped with a mini-jack plug (with the exception of Bluetooth models). This can be a plug on a non-detachable or detachable cable, or an adapter from another connector — for example, “2 RCA — mini-jack”.
— RCA.
RCA connector, also colloquially known as a "tulip", in this case is used as a line input, for receiving an analogue audio signal — similar to the same 3.5 mm mini-jack. The differences lie in several important points. First, RCA works on the principle of "one connector per channel", and the number of such connectors will depend on the audio format. For example, stereo acoustics will need a set of two such connectors, a 5.1 system will need six, etc. Secondly, RCA is quite popular in traditional audio equipment, but it is rather uncommon among computers. Therefore, this input is relatively rare in computer acoustics — mainly in fairly advanced models (including solutions with an external amplifier). In addition, we note that in sets with a subwoofer for connecting a “sub” in the main satellite, an RCA connector can also be provided, which in this case plays the role of an output.
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Subwoofer output. The presence of a connector for connecting a subwoofer allows you to further saturate the sound of the system with low frequencies. Naturally, a subwoofer is purchased separately. And the output itself serves as an option and allows you to expand the acoustics as needed.
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Headphone output. Headphone output located directly on the body of one of the speakers. Such a connector can be especially convenient when using headphones with a traditional desktop PC: connecting the “ears” to the speaker housing on the table can be much more convenient than pulling the wire to the system unit. Usually, the role of this output is played by a standard mini-Jack 3.5 mm jack — it is under it that most modern "ears" (both computer and general-purpose) are made.
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Microphone input. An input for connecting an external microphone, located directly on the speaker cabinet. The meaning of this function is the same as that of the headphone output described above: it is often more convenient to connect a microphone to a speaker standing on a table than directly to the system unit. The speakers themselves with this feature, usually, have an additional plug connected to the microphone input of the sound card.
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USB B. An interface that allows you to connect speakers to the USB port of a computer, laptop, etc. as an external peripheral. Such a connection can be useful, for example, in cases where the standard audio output is busy or located in a hard-to-reach place; in addition, it allows the speakers to work even if there is no sound card in the system (although this is very rare today). At the same time, speakers can also be powered via USB, which, with low power, makes it possible to do without a separate power source (for more details, see "Power from the USB port"). In addition, this connector may be responsible for additional functions — for example, controlling speaker functions from a PC through special software.
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Optical input. Digital input for high quality sound transmission, including multichannel. Such a connection is remarkable for its complete insensitivity to electrical interference, however, the fibre optic cable does not tolerate bending and strong pressure.
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Coaxial input. Digital audio input. Provides the possibility of transmitting multi-channel audio. Uses an RCA connector (colloquially referred to as a "tulip"), but is not compatible with the RCA interface described above. A coaxial connection, unlike an optical one, is subject to electromagnetic interference, but it does not require special delicacy in handling the cable.
