Frequency range
The audio frequency range supported by the projector's speakers.
When evaluating this parameter, it is worth remembering that the audibility range of the human ear is about 16 – 22,000 Hz (and narrows with age). If the projector's frequency range is narrower, this can result in "cutting" low or high frequencies (however, with a slight narrowing, this effect is almost imperceptible). There are models in which the frequency limit is much wider — however, this is a kind of "side effect" of high-quality acoustics and has no meaning other than advertising.
Also note that a wide frequency range in itself does not guarantee high-quality sound — a lot depends on other parameters of the projector.
Impedance
Impedance is the projector's resistance to alternating current, or more precisely, to the analog audio signal input from an external power amplifier. Actually, this parameter is of practical importance precisely if the device is planned to be used with an external amplifier. Ideally, the projector's impedance should match the impedance for which the amplifier is designed - otherwise, the volume may either decrease (if the impedance is too high), or distortion, overload, and even damage to the acoustics (if the impedance is too low) may occur.
Higher impedance is also thought to reduce the likelihood of interference. However, modern speakers (including sound projectors) have standard impedance values of 4, 6 or 8 ohms - the difference is not so great that the differences in sound quality are noticeable.
Inputs
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USB A. In this case, we mean a USB connector that allows you to connect external drives (flash drives, hard drives) to the projector and play content directly from them. At the same time, models with video outputs (see below) can often work as a media centre, outputting the video signal to a TV or other external display.
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mini-Jack (3.5 mm). By itself, the 3.5 mm plug can be used in different types of interfaces; in this case, it means a linear audio input with a mini-Jack socket. This input is mainly used to connect portable audio equipment (players, smartphones) to the sound projector.
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RCA. Technically, RCA (colloquially "tulip") is a type of connector that can be used in different interfaces. However, the term "RCA input" is used to refer only to line inputs for connecting an analogue signal in stereo format. Note that this input consists of two sockets for RCA cables, because. Only one channel of sound can be transmitted through one cable.
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Optical. Connector for digital audio signal connection via TOSLINK fibre optic cable. This interface allows for multi-channel audio transmission and is virtually immune to electrical interference; its disadvantage is the fragility of the cable.
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Coaxial S / P-DIF. A connector for connecting a digital audio signal via an elect
...rical cable with an RCA connector (not to be confused with linear RCA, described above). Similar to the optical input described above, in particular, the ability to transmit multi-channel audio through a single connector. At the same time, a coaxial cable, on the one hand, is not so delicate, and on the other hand, it is sensitive to electrical interference (therefore, it is advisable to use a special shielded wire for such a connection).
— Composite. In this case, we do not mean a full-format composite interface of three connectors that allows you to transmit audio and video signals, but only one connector for working with video. And since sound projectors don't display images, the composite input is used to send video through the projector to another device, such as a TV. The composite video interface does not allow working with HD and is not of high quality; on the other hand, it is widespread and can even be used to work with frankly outdated video equipment. Typically this input uses a yellow RCA plug.
— Component. An input designed to receive an analogue video signal for further transmission to another device — a TV, video projector, etc. This connection typically uses three RCA connectors, each carrying a different video component (hence the name). Due to this, the component interface has good bandwidth and picture quality, it allows you to work with HD and is considered the most advanced modern analogue video standard.
— IR control input. Connector for connecting an external infrared remote control receiver. When properly placed, such a receiver will allow you to use the remote control even in places where the signal from the remote control cannot reach the main (built-in) sensor — for example, in another room. Note that the role of the receiver can be played not only by a specialized device, but also by another component of the audio system — for example, an amplifier with an IR control output.Tweeter size
The diameter of the tweeters ("tweeters") installed in the sound projector. The larger the speaker diameter, the higher its power can be, but the lower the operating range. Therefore, tweeters, usually, are small in size, and the required power can be provided by their total number (see above).
Midrange speaker size
The diameter of the midrange drivers installed in the sound projector. An increase in the diameter of the speaker has a positive effect on its power (due to an increase in the usable area) and reduces the operating frequency range. Therefore, midrange heads can be noticeably larger than tweeters (see above). More detailed data on the diameter of the speakers can be found in special sources.
Woofer size (LF/MF)
The diameter of the woofers (or combined woofers, in two-way systems) of the speakers installed in the sound projector. For speakers in this range, large size is especially important - it is the cones of large diameter that work best at low frequencies, while providing good power. It is believed that for a head operating in the subwoofer format, a size of at least 200 mm is desirable. But the low-frequency speakers of the general range can be relatively small.
Control
The ability to control the soundbar, in addition to the standard push-button from the device case, also includes control from the
remote control,
the TV remote control to which the acoustics are connected, through the application
from a smartphone or tablet, and in some cases using a
voice assistant. More details about each of them:
— Remote control. The presence in the configuration of the classic remote control on IR sensors, like those used in TVs. It can contain much more settings functions than the controls on the body of the device and, of course, makes it easier to control the soundbar.
— TV remote control (HDMI-CEC). Connecting the soundbar via the HDMI port allows you to control it via the HDMI-CEC protocol via the TV remote control. This solution will reduce the number of remotes in the room and facilitate the comfort of the settings. However, the functionality of the "non-native" remote control may be limited. In this case, the compatibility of the TV and the soundbar can be achieved using other protocols (not necessarily HDMI-CEC).
— Smartphone control. The ability to control the soundbar through the application. This makes it easier to “search” for the remote control, because the phone is always at hand. The application also has extensive settings and such control is highly likely to be supported by t
...he TV, which allows you to execute absolutely any commands from your smartphone for a comfortable pastime on the TV.
— Voice assistant. This is not about the assistant built into the soundbar itself, but about compatibility with external devices that have this function (for example, with a smartphone or tablet). But even such compatibility allows you to give commands to the voice projector by voice — this is often more convenient than more traditional control methods. The specific set of supported commands and languages may vary depending on the voice assistant and its specific version. And among the most popular at the moment are Google Assistant, Apple Siri, Amazon Alexa.