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.
Subwoofer speaker size
The diameter of the speaker in the subwoofer used by the sound projector.
It is believed that the larger the speaker, the louder the sub and the deeper and richer sound it can provide. Models up to 200 mm in size are entry level; This is exactly the size that built-in subwoofers usually have (see above). But free-standing bass speakers can use larger speakers, up to 254 mm (10").
Interfaces
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Airplay. Wireless technology for connecting an external signal source to the projector. Developed by Apple, it is mainly used to connect with its devices (for example, iPad tablets or MacBook laptops), although it is also used by other manufacturers. AirPlay allows you to transfer not only sound, but also text and graphic information, and even video, which can be useful when connecting the projector to a TV. This technology, by definition, means support for Wi-Fi (see below), because. it is based on this interface.
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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 "multi-room" format, that is, the simultaneous transmission of several audio signals to different compatible devices installed in different places. In this way, you can, for example, turn on an online broadcast of a news programme 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.
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Chromecast. The original name is Google Cast. A 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 soundbar, the broadcast is standar
...dly carried out via Wi-Fi, while the receiver and signal source must be in the same Wi-Fi network (Chromecast media players are an exception). 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, among others, in the YouTube and Netflix apps for Android and iOS, as well as in the web versions of these apps for Chrome. Thanks to this format, this technology is extremely widespread nowadays, and the ability to connect a particular gadget to an audio system with a Chromecast is usually limited to the ability to install appropriate applications on this gadget.
— Wi-Fi. Wireless technology with multiple applications. One of them is connecting to a computer network; in sound projectors, it is primarily used for local resources (see DLNA below) or AirPlay technology (see above), as well as for controlling the projector over a network. Another option is to connect directly to other devices. The possibilities of such a connection in different models may also be different; one of the most popular options is remote control of the projector from a smartphone, tablet, etc.
— Bluetooth. Wireless technology designed to directly connect different electronic devices to each other. In sound projectors, it is primarily used to broadcast audio wirelessly from another Bluetooth device, such as a smartphone or laptop. However, there may be other options — for example, connecting wireless headphones to the projector itself or remote control from the same smartphone. It is worth noting here that the sound quality when transmitting via Bluetooth is somewhat lower than with a wired connection; on the other hand, this is offset by convenience, and some models of sound projectors may even have a "sound restoration" system.
— NFC. NFC is a wireless communication technology over short distances, up to 10 cm. In sound projectors, it is used mainly as an auxiliary, to facilitate connection via Wi-Fi or Bluetooth. It looks like this: instead of manually digging into the settings, just bring an NFC-compatible device to the projector chip and confirm the connection.
— FM radio. The projector has a built-in FM tuner. This function actually turns the device into a full-fledged radio receiver, allowing you to receive broadcasts on the FM band (which broadcasts most music radio stations). Note that some models with a tuner may support other bands, such as AM or digital DAB.
— LAN. A standard wired connection to a computer network, also known as Ethernet or RJ-45. Like Wi-Fi (see above), in sound projectors it is used primarily for working on a local network; however, LAN capabilities can include both playback of network content via DLNA (see below) and control of projector settings via a network from a computer. A wired connection is not as convenient as Wi-Fi due to the need to run a cable, but it is more reliable and can come in handy when the air is “loaded” (an abundance of Wi-Fi devices nearby).
— DLNA. A technology used to connect various electronic devices into a single digital network with the ability to directly exchange content. Devices for which support for this standard is claimed are able to effectively interact regardless of the manufacturer. And the network itself works on the basis of a conventional computer "local area", connection to it is carried out via LAN or Wi-Fi (see above). In sound projectors, DLNA can be used, for example, to play music from a computer hard drive.
— RS-232. A service interface used to connect the sound projector to a computer and control the sound settings from the PC through a special programme. On some models, it can also be used to update the firmware.
— Connecting an iPod. Special interface for connecting Apple iPod players. Most often it is based on a regular USB connector, to which the player is connected via an adapter cable; however, it may look like a dock — a stand with a proprietary connector, where the gadget is directly placed. Anyway, connecting in this way provides not only playing music from the player, but also other possibilities — for example, switching tracks from the projector's remote control, charging the battery, etc.
— Wireless connection to TV. Ability to connect the sound projector to the TV wirelessly. The advantage of this option is obvious: it eliminates the hassle of additional cables. On the other hand, a wireless connection is usually based on a certain proprietary technology (LG Sound Sync, TV SoundConnect, etc.) and requires a TV that supports the corresponding technology to work. This limits the use of this feature. In addition, such a connection is more susceptible to interference than a wired one, and “wireless” projectors are more expensive than wired ones. Therefore, it is worth specifically looking for a model with such a function if you have a TV with wireless technology support and at the same time the absence of extra wires is fundamental.Display
The presence of its own display in the design of the soundbar.
As displays, usually, small screens with the simplest LCD matrices are used. Various service information can be displayed on such a
screen : volume level, operating mode, active inputs and outputs, equalizer settings, etc. This makes management easier and more intuitive.