Comparison LG OLED55B2 55 " vs LG OLED55A2 55 "

The highest frame rate supported by the TV.

Note that in this case we are talking specifically about the screen’s own frame rate, without additional image processing (see “Index of dynamic scenes”). This frequency must be no lower than the frame rate in the video being played - otherwise there may be jerks, interference and other unpleasant phenomena that degrade the quality of the picture. In addition, the higher the frame rate, the smoother and smoother the movement in the frame will look, and the better the detail of moving objects will be. However, it is worth noting here that playback speed is often limited by the properties of the content, and not by the characteristics of the screen. For example, films are often recorded at a frequency of only 30 fps, or even 24 - 25 fps, while most modern TVs support frequencies of 50 or 60 Hz. This is enough even for viewing high-quality content in HD resolutions (speeds above 60 fps in such video are extremely rare), but there are also “faster” screens on the market: 100 Hz, 120 Hz and 144 Hz. Such speeds, as a rule, indicate a fairly high class of the screen; they also often imply the use of various technologies designed to improve the quality of dynamic scenes.

TV compatibility with special frame synchronization technologies used in AMD graphics cards.

You should pay attention to this parameter if you plan to use the TV as a gaming monitor for a PC or laptop with an AMD graphics adapter. Special timing technologies are used to match the screen refresh rate to the frame rate of the incoming video signal. Such a need arises for the reason that the frame rate issued by the graphics card can “float” when the load on the video adapter changes (this is especially true for demanding games); and if this frequency does not match the screen refresh rate – tears and other unwanted artifacts appear on the image.

The AMD technology used to eliminate this effect is called FreeSync. Nowadays, it is presented on the market in three versions — the original FreeSync and two extended ones:

– AMD FreeSync Premium Pro. The most advanced and functional version, formerly known as AMD FreeSync 2 HDR. In addition to refresh rate sync, it also includes support for HDR (see above), output at a frame rate of at least 120 Hz at Full HD resolution, as well as low frame rate compensation (LFC). The essence of LFC is that when the frame rate of the original video signal falls below the minimum frequency supported by the screen, the same frame is displayed on the screen several times, which allows to maintain the maximum smoothness of the “picture”.

— AMD FreeSync Premium. A somewha...t simplified version compared to FreeSync Premium Pro. It does not provide working with HDR, otherwise it is completely similar.

TV compatibility with special frame synchronization technologies used in NVIDIA graphics cards, namely G-Sync.

You should pay attention to this parameter if you plan to use the TV as a gaming monitor for a PC or laptop with an NVIDIA graphics adapter. Special timing technologies are used to match the screen refresh rate to the frame rate of the incoming video signal. Such a need arises for the reason that the frame rate issued by the graphics card can “float” when the load on the video adapter changes (this is especially true for resource-demanding games); and if this frequency does not match the screen refresh rate, tearing and other unwanted artifacts appear in the image.

The NVIDIA technology used to eliminate this effect is called G-Sync. Nowadays, you can find both the original G-Sync and the extended version — G-Sync Ultimate, which implements HDR support (see above). In addition, there are screens labeled “G-Sync Compatible”: they were not originally designed to work with G-Sync, but they turned out to be compatible with this technology (at least when working with video cards based on the GPU GeForce GTX 10 series and GeForce RTX 20th series).

A decoder can be broadly described as a standard in which digital audio (often multi-channel) is recorded. For normal playback of such sound, it is necessary that the corresponding decoder is supported by the device. Dolby Digital and DTS were the first in multi-channel decoding, gradually improving and introducing new features. The final stage for 2020 is Dolby Atmos and DTS X decoders.

– Dolby Atmos. A decoder that uses not a rigid distribution of sound across channels, but the processing of audio objects, due to which it can be used with almost any number of channels on a reproducing system — the sound will be divided between channels so that each audio object is heard as close as possible to its proper place. When using Dolby Atmos, ceiling speakers (or speakers facing the ceiling) are highly desirable. However, in extreme cases, you can do without them.

— DTS X. An analogue of the Dolby Atmos described above, when the sound is distributed not through individual channels, but through audio objects. The digital signal contains information about where (according to the director's intention) the object audible to the user should be and how it should move, and the processor of the reproducing device processes this information and determines exactly how the sound should be distributed over the available channels in order to achieve the required localization. Thanks to this, DTS X is not tied to a specific number of a...udio channels — there can be as many as you like, the system will automatically divide the sound into them, achieving the desired sound. Also note that this decoder allows you to separately adjust the volume of dialogues.

Among the features of the TV, first of all, it is worth noting its communication features, which include AirPlay 2, Wi-Fi(in particular Wi-Fi 5 and Wi-Fi 6), Miracast, Chromecast, MHL, DLNA, Bluetooth, in rare cases NFC. As a control, in addition to the classic remote control, there can be multimedia air mouse remote, voice control, voice assistant. As well as special features in the form of Ambilight from Philips. More about them:

— Airplay. TV support for AirPlay technology, usually in the AirPlay 2 version. Initially, this technology was created to broadcast multimedia content from Apple gadgets (iPhone, iPad, etc.) to external devices, including TVs. At the same time, it allows not only to play such content, but also provides many additional features — broadcasting additional information (title of the sound track, album cover), playback control from the TV remote control, etc. In AirPlay 2, in turn, the "multi-room" format was added — the ability to simultaneously broadcast several signals to...compatible devices installed in different places at home (for example, a movie on a TV and an online radio programme on sound system in the kitchen). In addition, in this version, support for voice control via Siri has appeared and a number of technical issues have been improved (in particular, buffering of streamed content).

— Wi-Fi. The presence of a built-in Wi-Fi module in the TV; the supported version of this technology can also be specified in this section. Nowadays, Wi-Fi can be used both for wireless access to the Internet and local networks, as well as for direct connection with other devices (for example, broadcasting video from a smartphone/tablet). The specific application of the wireless connection may be different, depending on the functionality of the TV; in addition to Internet access, examples include DLNA (see below), receiving or transmitting video via Wi-Di or Miracast, and using a mobile gadget as a remote control. However, almost all models with this feature belong to Smart TV (see above).
As for Wi-Fi versions, the most relevant nowadays are Wi-Fi 5, Wi-Fi 6 and Wi-Fi 6E. Also note that, in addition to these Wi-Fi standards, earlier ones are usually supported — so compatibility problems does not occur.

— TV shows recording. The ability to record TV programmes viewed on the TV. In most cases, it is supposed to record to a USB flash drive or other external USB drive, but there are other options: if you have a card reader (see "Inputs"), recording to a memory card can be provided, and some advanced TVs are equipped with quite capacious own drives. But this feature can be useful in cases where you need to save the broadcast — for example, so that someone can watch it later, or to save a TV programme with a family member to your home collection. In addition, many TVs with this feature also provide a Time Shift mode: if you need to leave the room, you can “pause the broadcast” and the TV will start recording it, and upon returning, you can continue watching from the point at which it was interrupted. Note that some TVs may require the installation of additional software to record TV programmes; for such models, this function is not always indicated, although it is technically available.

— MHL support. TV support MHL interface. This interface is used in portable electronics (smartphones, tablets) to transfer high-definition video and multi-channel audio to an external screen. In fact, it is a combination of microUSB and HDMI (see below): from a portable device, the signal is output through the universal microUSB port, and the TV receives video and audio through the MHL-enabled HDMI port, while simultaneously charging the connected gadget. The MHL bandwidth is sufficient for high-definition video and multi-channel audio.

— Miracast. TV support for Miracast technology. This technology allows you to broadcast video and audio signals via Wi-Fi technology (both to the TV and from it to portable electronics), while both devices are connected directly (Wi-Fi Direct) and do not require additional equipment, and the bandwidth is sufficient for Full HD video transmission and 5.1 multi-channel audio. Some time ago, TVs used a similar WiDi technology, but nowadays it is almost ousted from the market, and most manufacturers use Miracast.

— Chromecast. Chromecast technology allows you to quickly and easily stream video and audio from your smartphone, tablet or computer to your TV. In fact, Chromecast is a network media player, because after setting up this function, you can wirelessly display the video recorded on your smartphone on your TV with just one touch.

— Bluetooth. Bluetooth technology (any version) is used for direct wireless communication between different devices. How it is used on TVs may vary, depending on the functionality of a particular model (and version of Bluetooth). So, it is almost mandatory for Bluetooth TVs to be able to transfer sound to wireless headphones or speakers. In addition, other use cases may be provided: connecting keyboards, mice and game controllers, direct file exchange with a laptop, remote control from a smartphone or other gadget, etc. These details should be clarified separately. As for specific versions, in many models these details are not specified at all — for use for the intended purpose, “just Bluetooth” is enough. However, there are exceptions, and here the following options are relevant for modern TVs:

• Bluetooth v4.0. A version that combines traditional Bluetooth 2.1, a high-speed standard for transferring large files, and "Bluetooth Low Energy" for small amounts of information. All subsequent versions are built on these three components (with various improvements), and v 4.0 was the first where they appeared all together.
• Bluetooth v 4.1. Improvement of version 4.0, in which compatibility with mobile devices of the 4G LTE standard has been improved — so that the LTE and Bluetooth modules do not create mutual interference while working nearby.
• Bluetooth v4.2. Further development of version 4.0; updates that are relevant for TVs include mainly improving the reliability and noise immunity of communications.
• Bluetooth v5.0. One of the key improvements in version 5.0 compared to previous editions of the protocol was the presence of two special “Low Energy” modes – increased range (due to reduced speed) and increased speed (due to reduced range).
• Bluetooth v 5.1. Update of the v 5.0 version described above. In addition to general improvements in the quality and reliability of communication, this update has implemented such an interesting feature as determining the direction from which the Bluetooth signal is coming. Thanks to this, it becomes possible to determine the location of connected devices with an accuracy of up to a centimeter (for example, a remote control).
• Bluetooth v 5.2. The next, after 5.1, is the fifth-generation Bluetooth update. The main innovations in this version are a number of security improvements, additional power optimization in LE mode, and a new audio signal format for synchronized parallel playback on multiple devices.
• Bluetooth v 5.3. The Bluetooth v 5.3 wireless protocol was introduced at the beginning of 2022. Among the innovations, it accelerated the process of choosing the communication channel between the controller and the device, implemented the function of quickly switching between the state of operation in a small duty cycle and high-speed mode, improved the throughput and stability of the connection by reducing the susceptibility to interference. In case of unexpected interference in the Low Energy mode of operation, the procedure for selecting a communication channel for switching is now accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are seen in it.

— NFC. TV compatible with NFC technology; the NFC itself, usually, is built into the remote control or is made as a separate tag; installing it in the TV case is not very convenient. This technology provides wireless communication over short distances, usually up to 10 cm. Theoretically, the methods of its application can be different, but specifically on TVs, it is mainly used to facilitate communication via Wi-Fi or Bluetooth: just bring an NFC-compatible gadget (for example, a smartphone ) to the TV chip — and the devices will recognize each other automatically and either connect immediately, or the user will be required to confirm the connection. Anyway, it's easier than setting up the connection manually.

— DLNA support. The TV supports DLNA — Digital Living Network Alliance. This standard was created so that various types of home and portable electronics — smartphones, tablets, media centers, computers, etc. — was possible to combine into a single network and easily exchange content within this network, regardless of the model and manufacturer of individual devices. In the case of a TV, this means that you can directly stream video from other devices, such as a smartphone, to it via the network. The network itself is built on the basis of the usual local area network, both a wired LAN interface and wireless Wi-Fi can be used to connect to it.

— Ambilight. Screen backlight technology. In this case, the TV case illuminates the wall/partition located at the back, due to which a blurry halo appears around the screen contour in the colour of changing scenes. This effect visually expands the screen area, making watching TV more enjoyable. There are three types of backlighting in total: classic Ambilight (on the sides only), Ambilight Surround (on the sides and top), Ambilight Full Surround (from all sides). But manufacturers continue to work on improving the backlight. So, relatively recently, the Ambilight Spectra backlight has appeared, in which the colour matching algorithm has been significantly improved and the LEDs themselves have been optimized.

— Voice control. TV support for voice control allows you to dictate certain commands through the remote control. However, not all functions are covered by voice control and recognition accuracy may require re-entering the command. If you need a more extensive range of functions, then pay attention to the voice assistant.

— Multimedia (air mouse remote). Air mouse remotes are devices that have a gyroscope, which allows you not only to switch menu items with the “↑”, “↓” buttons, but to use the remote control as a mouse. By pointing it at the TV screen, a cursor will appear that moves in the direction of the remote control. This makes management easier and faster.

— Voice assistant. For a long time now, device control has been shifting to voice commands. For this, certain interfaces and systems are used. The most popular are Amazon Alexa and Google Assistant, as well as Samsung's own Bixby assistant. For "apple" devices, this is Apple Siri, but this technique is not presented on TVs. At the same time, unlike the voice control function, the voice assistant does not just turn on this or that function, mode, makes it louder, quieter, but allows you to perform certain operations in applications, whether it is to launch the desired clip in Youtube or display the weather in the browser.

The number of HDMI inputs provided in the design of the TV.

HDMI is a comprehensive digital interface that allows high-definition video and multi-channel audio to be transmitted over a single cable. It is widely used in modern HD equipment — in fact, the presence of such an output is mandatory for modern media centers, DVD players, etc. Therefore, LCD TVs in the vast majority of cases are equipped with at least one HDMI port. And the presence of several such ports allows you to simultaneously connect several signal sources and switch between them; in some models, the number of HDMI can reach 4 or even more. At the same time, some manufacturers use technologies that allow you to control devices connected to the TV via HDMI from a single remote control.

About the interface itself, see above, and its different versions differ in maximum resolution and other features. Here are the options found in modern TVs:

— v 1.4. The oldest of the current versions, released in 2009. However, it supports 3D video, capable of working with resolutions up to 4096x2160 at 24 fps, and in Full HD resolution, the frame rate can reach 120 fps. In addition to the original v.1.4, there are also improved modifications — v.1.4a and v.1.4b; they are similar in terms of basic features, in both cases the improvements affected mainly work with 3D content.

– v 2.0. Significant update to HDMI introduced in 2013. In this version, the maximum frame rate in 4K has increased to 60 fps, and the audio bandwidth has increased to 32 channels and 4 separate streams simultaneously. Also from the innovations, we can mention support for the ultra-wide format 21:9. In the v.2.0a update HDR support was added to the interface capabilities, in v.2.0b this feature was improved and expanded.

— v 2.1. Despite the similarity in name to v.2.0, this version, released in 2017, was a very large-scale update. In particular, it added support for 8K and even 10K at speeds up to 120 fps, as well as even more expanded features for working with HDR. Under this version, its own cable was released — HDMI Ultra High Speed, all HDMI 2.1 features are available only when using cables of this standard, although basic func...tions can be used with simpler cords.

— VRR. VRR (Variable Refresh Rate) adaptive frame rate synchronization technology allows you to adjust the refresh rate of the image on the TV screen in real time in accordance with the frame rate output by the game console or connected computer. The function ensures smooth rendering of dynamic scenes, eliminates frame breaks, and guarantees comfortable and stable gameplay. Realizable technology with standard HDMI v 2.1.

— ALLM. Automatic low latency mode for games (Auto Low Latency Mode). The TV switches to game mode when it detects a game console connection. Reducing the output delay on the TV panel screen is provided by suspending part of the image processing functions. The ALLM mode can also be useful for karaoke and video calls.

eARC. HDMI v 2.1 has an enhanced eARC (enhanced Audio Return Channel). The technology allows you to send higher quality audio from your TV to your soundbar or AV receiver. It claims to support the latest high bit rate audio formats up to 192 kHz, uncompressed 5.1 and 7.1, and 32-channel uncompressed audio. eARC also supports Dolby TrueHD, DTS-HD Master Audio, DTS:X, Dolby Atmos.

— CEC. The CEC (Consumer Electronics Control) system is designed for remote control of equipment connected to the TV using a single remote control. The devices are connected to the TV panel using an HDMI cable.

— 2 separate legs. Two legs as support are usually located on different sides of the lower face of the TV panel body. Such a design involves placing the TV on a large flat surface that extends along the entire lower side of the device. The TV is often more stable on two "legs" than on one leg.

— 1 leg on the platform. A support for the TV with a round or rectangular platform, which is in contact with the surface of the TV panel (table, stand, etc.) with its entire plane.

— 1 leg with supports. Stands of this kind consist of a single leg and a base of various geometric shapes that holds the TV. This solution ensures reliable stability of the TV panel, and in terms of design, it is a stylish element of the design of the structure.

— Monolithic. A solid stand with two or more attachment points to the bottom of the TV and monolithic frames as a solid support for installing the TV panel on a flat surface of a table or stand.