Comparison LG 55SM8200 55 " vs LG 55UM7450 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 TV's support of one or the other colour enhancement technology.

Such technologies usually involve image processing in software to provide brighter and/or more accurate colours. Specific processing methods may be different, some manufacturers do not specify technical details at all, limiting themselves to advertising statements. The effect of using such technologies can also vary: in some cases it is clearly visible, in others it is almost absent, depending on the features of the picture. It is also worth saying that this feature, usually, needs to be turned on manually in the TV menu (accordingly, it can be turned off if desired).

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.

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.

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.

The amount of random access memory (RAM) installed in the TV.

In general, this volume is selected by the manufacturer in such a way that the device can normally cope with the tasks that are claimed for it. On the other hand, all else being equal, more RAM ( 3 GB, 4 GB or more) usually means faster performance. This parameter is especially important if the TV runs on Android: such firmware allows the installation of additional applications that may have rather high requirements for RAM. However, TVs with 2 GB of RAM and below can also not be discounted — they just can't pull high-demanding applications. But do not forget that this is a TV, not a laptop.

The electrical power normally consumed by the TV. This parameter strongly depends on the screen size and sound power (see above), however, it can be determined by other parameters — primarily additional features and technologies implemented in the design. It is worth noting that most modern LCD TVs are quite economical, and most often this parameter does not play a significant role — in most cases, power consumption is about several tens of watts. And even large models with a diagonal of 70 – 90" consume about 200 – 300 W — this can be compared with the system unit of a low-power desktop PC.