Comparison Xiaomi Mi TV 4S 55 55 " vs Xiaomi Mi TV 4 55 55 "

The type of matrix used in the TV. Among them, OLED, QLED, QD-OLED and NanoCell deserve the most attention, which are found in TVs of the relevant price category. Now more about each of them and other more classic options:

— OLED. TVs with screens that use organic light-emitting diodes — OLED. Such LEDs can be used both to illuminate a traditional LCD matrix, and as elements from which a screen is built. In the first case, the advantages of OLED over traditional LED are compactness, extremely low power consumption, backlight uniformity, as well as excellent brightness and contrast ratios. And in matrices, consisting entirely of OLED, these advantages are even more pronounced. The main disadvantages of OLED TVs are the high price (which, however, is constantly decreasing as the technology develops and improves), as well as the susceptibility of organic pixels to burn-in during long-term broadcast of static images or pictures with static elements (TV channel logo, information panel, etc.).

— QLED. TVs with screens using "quantum dot" technology — QLED. Such screens differ from conventional LED matrices in the design of the backlight: multilayer colour filters in such a backlight are replaced with a thin-film light-transmitting coating based on nanoparticles, and traditional white LEDs are replaced with blue ones. This a...llows to achieve a significant increase in brightness and colour saturation at the same time as improving the quality of colour reproduction, besides, it reduces the thickness and reduces the power consumption of the screen. The disadvantage of QLED matrices is traditional — the high price.

— QD-OLED. A kind of hybrid version of matrices that combine “quantum dots” (Quantum Dot) and organic light-emitting diodes (OLED) in one bottle. The QD-OLED modification was introduced by Samsung at the end of 2021 in response to advanced OLED panels from LG. The technology takes the best from QLED and OLED: it is based on blue LEDs, self-luminous pixels (instead of external backlighting) and “quantum dots”, which play the role of colour filters, but at the same time practically do not attenuate the light (unlike traditional filters) . Thanks to the use of a number of advanced solutions, the creators managed to achieve very impressive characteristics, significantly superior to many other OLED matrices. Among them are high peak brightness from 1000 nits (cd/m²), excellent contrast and black depth, as well as colour coverage of over 90% according to the BT.2020 standard and more than 120% according to DCI-P3. Such matrices are found mainly in flagship TV panels.

— IPS. A type of matrix originally designed for high quality colour rendering. Indeed, IPS screens produce bright and rich colours, have a good colour gamut, and demonstrate wide viewing angles. The initial disadvantage of this technology was the low response time, but in modern modifications of IPS this point has been practically eliminated. Matrices of this type are very popular in the advanced budget and mid-price segment of TV panels.

— *VA. In this case, we mean one of the varieties of VA (Vertical Alignment) type matrices - MVA, PVA, Super PVA, etc. Specific varieties may vary slightly in properties, but they all have common features. In fact, *VA matrices are a more affordable alternative to IPS panels: they are relatively inexpensive, provide fairly good colour reproduction and viewing angles of up to 178°. The main disadvantage of such screens is the long response time, but in modern models this has been practically eliminated thanks to the constant improvement of technology. *VA matrices are used in TVs that are positioned as functional and at the same time affordable models.

— PLS. In fact, it is one of the varieties of the IPS matrices described above, developed by Samsung. According to the manufacturer, in such matrices it was possible to achieve higher brightness and contrast than in traditional IPS, as well as to slightly reduce the cost.

— NanoCell. Matrix based on quantum dots. This type of matrix is used in LG TVs and was first introduced in 2017. NanoCell matrices use the structure of classic LCD displays. But unlike the latter, they use so-called quantum dots instead of the classic general backlight, which provide monochromatic light. NanoCell technology reduces power consumption while increasing colour gamut and viewing angle. It is worth noting separately that NanoCell matrices are not the only ones using quantum dot technology. Similar solutions are offered by: Samsung (QLED matrix), Sony (Triluminos matrix), Hisense (ULED).

The level of static contrast provided by the TV screen.

Contrast in a general sense is the ratio in brightness between the brightest whites and the darkest blacks that the screen can produce. Other things being equal, the higher the screen contrast, the better the quality of colour reproduction and detail, the lower the likelihood that it will be impossible to see details in too bright or too dark areas of the image. Static contrast, on the other hand, describes the maximum difference in brightness that can be achieved within one frame without changing the brightness of the image — this is its difference from dynamic contrast (see below).

The values of static contrast are much lower than those of dynamic, but this characteristic is the most "honest". It is on it that the properties of the image seen on the screen at a particular moment depend, it is describes the basic properties of the screen, without taking into account the software tricks provided by the manufacturer in the hardware of the TV.

The level of dynamic contrast provided by the TV screen.

Contrast in a general sense is the ratio in brightness between the brightest whites and the darkest blacks that the screen can produce. Other things being equal, the higher the screen contrast, the better the quality of colour reproduction and detail, the lower the likelihood that it will be impossible to see details in too bright or too dark areas of the image. Formally, the main characteristic of screens is static contrast (see above), but even in advanced matrices it is relatively low. Therefore, manufacturers went to the trick, introducing such a characteristic as "dynamic contrast".

Dynamic contrast ratio is the difference between the brightest whites at the highest screen brightness settings and the darkest blacks at the lowest. These contrast ratios can be quite impressive—much higher than static—however, it is impossible to achieve such values within a single frame, and dynamic contrast ratio is stated more for promotional purposes than for describing the actual specifications of the screen. However, it cannot be said that this indicator is completely unrelated to reality. The fact is that many TVs use automatic brightness control, which changes the settings depending on the characteristics of the image. This control is based on the fact that when displaying bright scenes, there is no need to provide a deep black level, and in dark scenes, high brightness of light areas is not needed — th...ese are the features of the human eye. This means that in bright scenes you can increase the overall brightness, and in dark scenes you can reduce it; the maximum brightness difference achievable in this mode of operation is precisely described by dynamic contrast.

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 audi...o 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.

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 functio...ns can be used with simpler cords.

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.

Most TVs have a VESA wall mount which may vary in size. The basis for such mount is a rectangular plate with four holes for screws in the corners. The main characteristic of such a mount is the distance between the holes — it is measured along the sides of the rectangle and is expressed in two numbers. The original VESA format is 100x100, these mounts are used for most medium-sized LCD TVs. For small screens, 75x75 mounts are provided, for large ones — 200x200 and more (up to 800x400).

However, there are also models that are equipped with a standard (proprietary) mount from the manufacturer. Mostly these are either ultra-thin TVs or designer lines. Anyway, the mount in the kit is suitable only for the selected model.

— 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.