Comparison LG 49UJ740V 49 " vs LG 49SJ810V 49 "

TV support 4K upscaling feature.

This feature is only found in models with 4K screens and above (see "Resolution"). It allows to increase the resolution of the original image to 4K (3840x2160), if it is initially lower — for example, to view a movie in 4K that was originally recorded in Full HD (1920x1080). This is not just about “stretching” the image to fill the screen (all TVs are capable of doing this), but about special processing, due to which the actual video resolution is increased. Of course, such video will still be inferior to content originally recorded in 4K; however, upscaling provides a noticeable improvement in quality over the raw signal.

Dynamic Scene Index (DSI) provided by the TV screen.

DSI is a rather specific parameter that can be called "visible framerate". Its appearance is due to the fact that a high frame rate is highly desirable for dynamic scenes — it provides smooth images and good detail of moving objects. However, for technical reasons, it is not possible to achieve indicators above 200 Hz in most screens. In order to remedy the situation, manufacturers use special technologies that create the effect of increasing the frame rate.

Such technologies may have different names, but they have the same principle of operation — inserting additional frames between the "own" frames of the video being played. And the dynamic scene index describes the overall effectiveness of such technology used in a TV. For example, a DSI of 200 Hz means that the image quality on the screen approximates a frame rate of 200 Hz, although the actual frame rate is often as low as 50-60 Hz.

In the most advanced models, the dynamic scene index can be up to 3000 Hz, and options above 3000 Hz are considered to be TVs with a high dynamic scene index. However, it is worth noting that such specifications are more of an advertising ploy than a real advantage: in fact, the threshold for human perception is 400 – 500 Hz, a further increase in the DSI does not give a clearly visible improvement in the image.

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.

— 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.