Comparison TCL 65C7K vs TCL 65C855

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 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.

Color gamut describes the range of colors that can be displayed on a screen. It is indicated in percentages, but not relative to the entire variety of visible colors, rather to a specific color space (color model). This is because no modern screen can display all the colors visible to the human eye. Nevertheless, the larger the color gamut, the broader the screen's capabilities, and the better its color reproduction quality.

DCI-P3 is an advanced color model mainly used in digital cinemas. It is significantly wider than the standard sRGB, providing more accurate and realistic colors. However, in practice, this model is primarily used for professional filmmaking and other tasks of a similar level. This is why televisions with this standard display movies and series as close as possible to the director's vision.

The brand of the speaker system installed in the TV.

This item is indicated if the TV is equipped with advanced sound system, which is noticeably superior in quality to conventional speakers. Such information further emphasizes the high level of the device. At the same time, the specifications usually do not contain the full name of the speaker system, but only the brand name — for example, Bang & Olufsen, Harman Kardon, JBL, etc.: even such information is quite enough in this case.

The nominal power of the sound produced by the TV's sound system.

The larger the screen and the greater the estimated distance to the viewer, the more powerful the sound system must be in order to be heard normally. Manufacturers take this moment into account, moreover, most often they also provide a solid volume margin. So if a TV is bought for home viewing in a quiet, calm environment, you can not pay much attention to the sound power: it is guaranteed to be enough for such a usage. It makes sense to specifically look for models with high-power speakers for a noisy environment — for example, a cafe or other public space. Detailed recommendations on this matter can be found in special sources, but here we note that even in such cases, connecting external speakers can be a good alternative.

The number of speakers installed in the TV.

Theoretically, one speaker is enough to work with sound, but most entry-level and mid-range models (as well as many premium devices) provide two speakers — for stereo operation, which allows to achieve some surround sound effect. And more than two speakers usually means the TV has enhanced audio capabilities such as a subwoofer or soundbar (see below).

The presence of a subwoofer as part of the TV sound system.

A subwoofer is a specialized speaker for bass and ultra-low frequencies. It makes the sound richer in the bass, which is especially useful when watching adventure films with appropriate sound effects (bumps, explosions), as well as concerts. It should noted that the specifications of built-in subwoofers are usually much more limited than those of external ones; so don't expect cinema-like bass from a TV audio system. However, the advantage in bass quality for such TVs (compared to models without a subwoofer) will still be noticeable.

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 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.