Comparison LG OLED55C7V 55 " vs LG 55SJ930V 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 type of coating used on the TV screen.

— Matte. Historically, the first type of coating for LCD screens, which is often found today. Screens with such a coating generally have average characteristics of brightness, saturation and colour reproduction quality, in terms of these indicators they are inferior to glossy counterparts. However, the matte coating has one important advantage: it has virtually no glare from ambient light. In some situations, this can be an important advantage — for example, if the TV is installed opposite the window. And for some users it is more pleasant to look at the screen without glare, albeit relatively dim.

— Glossy. A coating designed to improve the brightness and colour quality of the visible image compared to matte screens. The creators have managed to achieve this goal: "glossy" screens really provide rich, vibrant colours and a brighter image. The key disadvantage of such screens is the appearance of glare from ambient light on them — this can ruin the whole viewing experience. Because of this, the classic glossy coating is practically not used today, anti-glare solutions have taken its place (see below).

— Glossy (anti-glare). Modification of the glossy coating, created, as the name implies, in order to eliminate the main drawback of the classic gloss — glare from external lighting. This is not to say th...at such screens do not glare at all, but there are much less reflections on them than on ordinary glossy ones. As for the image quality, it is at least not much worse, and often even better (especially since such coatings are constantly being improved). Thanks to all this, most modern TVs of all price categories are equipped with anti-glare screens.

The maximum brightness of the image provided by the TV screen.

The image on the screen should be bright enough so that you do not have to strain your eyes unnecessarily to view it. However, too high brightness is undesirable — it will also lead to fatigue. The optimal brightness level depends on the surrounding conditions: the more intense the ambient light, the brighter the TV screen should be. So, on a sunny day, the screen may have to be “turned up” to the maximum, and in the evening, in dimmed light, a relatively dim image will be more comfortable. In addition note that large screens require higher brightness, since they are designed for a greater distance from the viewer.

Thus, the higher the number in this paragraph, the greater the margin of brightness this model has, the better it will show itself in intense ambient light. The lowest indicator sufficient for more or less comfortable viewing in any conditions is 300 cd/m² for models with a diagonal of up to 32", 400 cd/m² for models in the range of 32 – 55" and 600 cd/m² for large screens of 60" and more. In this case, the brightness margin anyway will not be superfluous. But with lower indicators, you may have to darken the room somewhat for comfortable viewing.

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.

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.

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 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.

— Coaxial (S/P-DIF). An interface for transmitting audio in digital format, which allows to transmit multi-channel audio via a single cable with an RCA connector (“tulip”). In terms of resistance to interference, this standard is somewhat inferior to the optical one (see below) — this is due to the fundamental differences between these interfaces. On the other hand, electrical cable is more reliable than optical fibre and is not as sensitive to pressure and bending.

— Optical. An output for transmission of a digital audio signal on a fibre optic cable; allows the transmission of multi-channel audio. Notable for its complete insensitivity to electromagnetic interference. On the other hand, fibre optic cable is quite fragile, it must be protected from bending and strong pressure.

— Mini-Jack (3.5 mm) for headphones. Standard 3.5mm headphone jack. Headphones can come in handy if you need to keep quiet and you can’t use the TV speakers – for example, at a later time of the day; or vice versa, if the environment is noisy and the sound of the TV is hard to hear. Most modern "ears" use a mini-Jack plug, so this connector is the standard headphone output in TVs. And in some models, this output can also be used as a linear output — for example, to connect individual speakers, a sound recording device, etc.

— Subwoofer. A separate output for connectin...g a subwoofer to a TV is a speaker for reproducing low and ultra-low frequencies. Audio systems without subwoofers usually reproduce these frequencies quite poorly. The use of subwoofer allows you to achieve the most deep and rich sound, which is especially important when watching movies with a lot of special effects or high-quality recordings from concerts. At the same time, it is worth noting that such outputs are quite rare in TVs: it is assumed that a full-format external audio system is more suitable for a demanding listener than a separate subwoofer.

— Line. Standard analogue audio interface; usually, provides the transmission of two-channel stereo. It is used primarily to connect active speakers and other audio equipment (for example, audio receivers or power amplifiers) to TVs. It can use different types of connectors, but most often it provides either a 3.5 mm mini-Jack or a pair of RCA jacks for tulip cables. Note that it is a separate line output that is meant here; in some models, this function can be performed by a 3.5 mm headphone jack (see above), but for them the presence of a line-out is not indicated.

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.