Comparison Sony KD-55X80K 55 " vs Sony KD-55X81J 55 "

— Smart TV (own system). The operating system of the TV is represented by the manufacturer's proprietary software shell. Usually, such operating systems have an attractive and understandable menu, similar to a traditional Smart TV. A proprietary operating system is developed by the manufacturer for the hardware resources of a particular TV model or a whole line. But, as practice shows, compared to the classic Smart TV, the functionality of its own system often has significant limitations, and the system itself, in fact, is a stripped-down version of a full-fledged Smart TV.

— Smart TV (Android AOSP). This type of operating system is a modification of the popular Android OS, mainly notable for being open source. It is a versatile operating system that gives the user much more freedom to create changes and customizations within the system itself. At the same time, the installation and stability of certain applications on this platform are not guaranteed, and the overall system management was not specially “tailored” for large screens, which may cause some inconvenience. First of all, such solutions will arouse interest among users who understand the features of the Android OS, like to customize and control everything for themselves, and have time for this.

— Android TV. TVs of this type boast full-fledged Android TV software, specially adapted to work on...large screens. In accordance with the name, it is a kind of Android OS, specially “sharpened” for TVs / projectors, etc. In addition to the common features of all “Androids” (such as the ability to install additional applications, including even games), it has a number of special features: optimized interface, integration with smartphones (including the ability to use them as a remote control), voice search, etc. Thanks to this, TVs with this feature are significantly superior in functionality to models with a “regular” Smart TV. Of course, a dedicated processor, graphics subsystem and memory are provided for the operation of a multifunctional OS, and the presence of such hardware resources is reflected in the total cost of the TV. Given the same optical design, models with Android TV will cost more than classic devices with a simple multi-line menu.

— Google TV. Rebranding of the Android TV platform for TVs and smart set-top boxes, or rather, a new shell on top of the operating system under the sign of the “green droid”, introduced since 2021. Among the innovations, it has a redesigned user interface, an improved knowledge base that more efficiently distributes content by genre and collects search information from the entire list of installed applications and subscriptions. The voice assistant now understands the needs of the audience better and provides a detailed list of what was found. A separate tab in the interface contains live broadcasts of current events, whether it be sports events or a rocket launch to Mars. Among other things, the aspects that involve the use of TV as a command post for managing a single ecosystem of a “smart” home have been improved in the system.

— Edge LED — side backlight of the matrix. In this case, the LEDs are distributed around the perimeter of the screen. To evenly distribute the backlight, the background of the matrix has a special reflector. An important advantage of TVs with Edge LED backlighting is the minimum thickness of the device. Among the shortcomings, one can note the presence of glare at the edges, which appear under certain conditions. Glare may be visible in scenes where dark hues predominate.

— Direct LED — rear matrix backlight. In this case, the LEDs are evenly distributed over the entire screen area. The Direct LED backlight makes the image contrast and bright at the same time. TVs with this technology have good colour reproduction. Among the shortcomings can be noted increased power consumption and increased dimensions. Additionally, such TVs have a large delay (Input lag), which is why Direct LED backlit screens are poorly suited for dynamic games.

— FALD (Full-Array Local Dimming) is a backlight technology widely used in LG TVs. A close analogue of FALD is the Direct LED backlight. The LEDs are also evenly spaced across the entire surface of the matrix, but FALD technology provides a bright, colour-rich image with high contrast. Another distinctive feature of FALD is the ability to reproduce natural blacks. When black is displayed on the screen, the LEDs are turn...ed off in groups, by sector, which allows to make black extremely saturated. Of course, the abundance of LEDs on the matrix makes the TV more massive, and at the same time heavy. The appetite for electricity in such models is above average.

— Mini LED. Screen backlight system on a substrate of reduced LEDs (hence the Mini prefix). On the same plane of the TV panel, the number of LEDs has increased several times, if we draw parallels with traditional LED systems. As a result, the canvas with Mini LED backlight has many times more local dimming zones of the picture (Local Dimming), which is necessary for the correct operation of the extended dynamic range image technology. For playing HDR content, Mini LED systems are much better than ordinary LCDs.

— Dual LED. Proprietary backlight system used in Samsung TVs. The technology involves illuminating the image on the screen with two types of LEDs: one emits light in a cold spectrum, the other in a warm one. The Dual LED enhances colour reproduction and enhances detail contrast by adapting the colour tone of the picture according to the content on the screen.

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 support for one or another brightness / contrast enhancement technology.

Usually, in this case, software image processing is implied, in such a way as to improve brightness and/or contrast (if necessary). Specific processing methods may be different — in particular, in some cases we are actually talking about turning standard content into HDR (see above), and some manufacturers do not specify technical details at all. The effectiveness of different technologies can also be different, and besides, it is highly dependent on the specific content: in some cases, the improvement will be obvious, in others it may be almost imperceptible. Also note that this feature is not always useful, so in most models it is turned off.

Types of digital tuners (receivers) provided for in the design of the TV.

Such tuners are necessary for receiving digital TV broadcasts; for normal operation, the broadcast standard must match the type of tuner (with some exceptions, see below). Note that the receivers are also available as separate devices; however, it is easier (and often cheaper) to buy a TV with a built-in tuner of the desired format. In modern TV you can find terrestrial tuners DVB-T2, cable DVB-C and satellite DVB-S and DVB-S2, here are their main features:

— DVB-T2 (terrestrial). The main modern standard for digital broadcasting. Such broadcasting has a number of advantages over traditional analogue broadcasting: it allows higher resolution and multi-channel audio transmission, with better sound and picture quality, and this quality is fully preserved until the signal weakens to a critical level. However, in some countries digital terrestrial broadcasting is just being put into operation, so it will not hurt to check the availability of DVB-T2 coverage in your area.

— DVB-C (cable). The main modern standard for digital broadcasting in cable networks. Despite the advent of the more advanced DVB-C2, it still continues to be widely used, and most likely this situation will not change for a long time.

— DVB-S (satellite). The first...generation of the digital DVB standard for satellite broadcasting. Nowadays, it is relatively rare due to the advent of a more advanced DVB-S2, which is also backwards compatible with the original DVB-S.

— DVB-S2 (satellite). The most advanced and popular of today's digital satellite broadcasting standards. Being the heir to DVB-S, has retained compatibility with it; therefore, manufacturers often limit themselves to installing only a DVB-S2 tuner on their TVs — it allows you to receive both major satellite broadcast formats.

The ability to display on the TV screen "pictures" from several sources at once. Usually, in the picture-in-picture mode, a small window is displayed in the background of the main image (or several such windows), which is displayed in full screen, in it you can see an additional image. One of the most popular ways to use this “multitasking” is to skip commercial breaks in TV broadcasts: for this time, you can switch the main image to a more interesting channel, and leave the ad in the auxiliary window to not miss the end of the commercial and continue watching. It is worth considering, however, that the images for each window must come from different sources — in other words, it will not work to turn on two channels at the same time from one tuner.

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, Bluetooth. As a control, in addition to the classic remote control, there can be 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, 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.

— 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.

— 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.

— 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.

— 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.

The TV's connectivity options are based not only on wireless technologies (described above), but also on a wired connection. In particular, additional video transmission can be carried out through VGA, composite AV connectors . Some of them also provide sound transmission, in addition to which there may be a mini-Jack (3.5 mm) and other ports for communication with external devices. More about them:

— USB. Connector for connecting external peripheral devices. The presence of USB means at least that the TV is capable of playing content from flash drives and other external USB media. In addition, there may be other ways to use this input: recording TV programs to external media, connecting a WEB camera (see same paragraph), keyboard and mouse to use the built-in browser and other software, etc. The specific set of options depends on the functionality of the TV, it should be specified separately in each case.

— Card reader. A device for working with memory cards, most often in SD format. The main use of the card reader is to play content from such cards on a TV; such an opportunity is especially convenient for viewing materials from photo and video cameras — it is in such devices that memory cards are widely used. There may be other ways to use this function — fo...r example, recording from the broadcast or even exchanging files between the card and the TV's storage. It is worth bearing in mind that SD cards have several subtypes — original SD, SD HC and SD XC, and not all of them may be supported by the card reader.

— LAN. Standard connector for wired connection to computer networks (both local and the Internet). Mostly found in models with Smart TV support (including Android TV devices; see related paragraphs). A wired connection is less convenient than Wi-Fi, not as aesthetically pleasing, so manufacturers place more emphasis on a wireless connection, as a result of which the speed indicators of the LAN connector are not indicated, and in some cases may be unacceptable for 4K broadcasts.

— VGA. Analogue video input, also known as D-sub 15 pin. Initially, the VGA interface was developed for computers, but due to the emergence of more advanced standards like HDMI (see below) and technical limitations (the maximum resolution is only 1280x1024, the inability to transmit sound), it is considered obsolete and is used less and less. So it makes sense to specifically look for a TV with such a connector mainly in cases where it is planned to be used as a monitor for an outdated computer or laptop.

– Composite AV input. Analogue input for video and audio transmission. Previously, it consisted of 3 RCA sockets (yellow for video, white and red for audio) and was connected to the equipment accordingly. Now in many models you can find an AV output, which is a single connector in the “headphone” format, to which a tee cable is already connected (check availability in the package).

— COM port (RS-232). A connector originally designed for computer equipment. In TVs, it is used as a service interface: for troubleshooting, updating firmware, adjusting TV parameters and various calibrations, integrating the TV into centralized remote control systems, etc. Note that the COM port may differ in shape and contact group in different TV models. It is often designated as RS-232C.