LG 55 B4 vs TCL C6K

The brightness results in HDR materials LG B4 are very good. It is true that none of them exceed 1000 nits, although the luminance stability is excellent and looks practically the same in every scenario. The only moment where the tested television performs worse is the last scene, although this should not come as a surprise. Large frames filled with a lot of white have always been, and will likely continue to be, somewhat of a weakness for OLED televisions. However, the combination of perfect contrast, black levels, and brightness in the LG B4 allows for a full spectrum of the HDR effect. Additionally, the incredibly high coverage of the DCI-P3 colour gamut, which reached 99%, deserves recognition. As a result, colours look incredibly vibrant and stunning.

TCL C6K is a moderately bright television that can showcase its full capabilities in the best movie conditions – the maximum brightness is around 600 nits. In scenes with large, intense light sources, the HDR effect can be truly satisfying, providing a sense of cinematic sparkle. However, it's important to remember that with local dimming management, there are situations where some elements become dimmed, and sometimes even barely visible. It is clear that there is a lack of proper optimization of the algorithms, although looking at the technical parameters in this price range, the build quality performs very well.

The best factory mode prepared by the manufacturer is "Filmmaker," and we used it throughout the entire testing procedure. We must admit that the unit we received straight out of the box had quite decent colour reproduction. The biggest issue in both SDR and HDR content turned out to be white balance. In the former, there was a strong dominance of red, resulting in a noticeable yellow tint in the displayed image, particularly evident on skin tones and whites. In high-quality materials, this colour was also pronounced, but due to a lack of blue, there were also signs of green visible. Besides these shortcomings, we also encountered issues with greyscale and the colours themselves.

This year's TCL televisions have introduced the Filmmaker mode, and it must be said that it is definitely the best choice right out of the box. This is the mode we recommend for everyday viewing of movies and series. Unfortunately, as is often the case, the best does not mean perfect. In the case of SDR content, the image was too warm, as the red was quite prominent in the white balance. On the other hand, with HDR content, we had the opposite impression – the image became cooler than it should have been, due to an excess of blue. There is also the brightness characteristic, which at times led to overexposure. In practice, these issues combined resulted in quite noticeable errors in colour tests, which are hard to accept in a mode advertised as “by the creators”.

LG B4 has been providing very advanced calibration tools in its TVs for years. We can even say that as the only manufacturer on the market, it allows for such deep intervention in image adjustment. Thanks to these, we were able to calibrate the device so well. The evidence of this is the extremely low deltaE errors, which can be said to stand at a reference level. Both SDR and HDR materials now look exactly as the film director intended. It is no coincidence that TVs of this brand are most often used as preview screens for various graphic or post-production studios.

Thanks to the white balance adjustment, we were able to significantly reduce the C6K's tendency to distort colours, which resulted in a very good end result. After calibration, we won't observe the effect of excessive warming of scenes in SDR or overly cooling the image in HDR. However, it is worth taking a closer look at the brightness characteristics. In SDR content, it's hard to have major objections – the picture looks really good, especially in older movies, TV shows, or material from YouTube. It performs significantly worse with HDR content. An analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in movies), the limitations of the construction become apparent. The television tends to excessively brighten the smallest fragments of the frame, and in other situations, it can overly dim the entire scene. The effect of calibration is therefore noticeable, and regarding colourimetry, the C6K has really gained a lot, but certain limitations resulting from local dimming and actually from its management by the C6K simply cannot be overlooked.

In this paragraph, we will take another look at the tonal transition smoothing feature, but we will also check how the TV handles lower quality material. As we have managed to check, the setting responsible for smooth gradation works quite effectively, although it has its weaker moments. While the feature works well with SDR content, it becomes less useful with HDR content. Even at the lowest of options, it blurs essential details, so we advise against using it.

The image scaling on LG B4 is rated fairly moderately positively. Although there is no edge splitting, the image itself is naturally "soft". We can change this by adjusting the sharpness slider.

TCL C6K performs quite well in terms of upscaling. Lower quality materials appear acceptable, and the absence of overscan issues means the image is displayed in full, without cropping. However, one cannot expect miracles – very low quality content won't come to life here, as the image processor has its limitations. On thin lines or details, there is characteristic tearing visible, which indicates a lack of advanced image enhancement algorithms. It is also a shame that the C6K lacks the function of smoothing tonal transitions – in older films or video materials, colour banding can be noticeable and may be distracting during longer viewing sessions.

The maximum refresh rate we can set on the LG B4 is 120 Hz. This is the absolute minimum for those who require high image smoothness. The manufacturer has implemented a multi-level motion smoother called "TruMotion". It has been divided into two separate sliders that adjust the sharpness of moving images (De-Blur) and stuttering (De-Judder). Both sliders can be set in the range from 0 to 10, with each level affecting the degree of smoothness, so everyone can find their sweet spot.

The LG OLED B4 panel features an average response time of 0.1 ms (which directly results from our measurements), allowing for an incredibly clear image, unattainable for LCD TVs, which have response times of even several milliseconds. This can be clearly seen in images from the "UFO Test", showing no trace of blur trailing behind the object.

TCL C6K uses a 144 Hz panel, which is a significant advantage in this price range. It's an important step forward in comparison to the previous model C655 PRO, which only offered 60 Hz in 4K. The difference is especially noticeable when watching sports or playing games – the ball, players, or fast action in the game are displayed more clearly and without losing detail. An interesting fact is the panel's ability to operate at 240 Hz, which the manufacturer doesn't mention in official materials. We will return to this topic when discussing the PC gaming mode.

TCL has also added a feature for movie watchers: "Motion Clarity," which allows users to adjust the image according to their preferences with two simple sliders. You can either keep the visible film frame or opt for a very smooth, almost theatrical effect. This way, everyone can find settings that match their taste.

The LG B4 television is equipped with four full-fledged HDMI 2.1 ports with a full bandwidth of 48Gbps. All functions corresponding to this standard activated without any issues, and throughout the entire testing procedure, they caused no problems. The combination of such extensive functionality and low input lags leads us to say that the tested television is truly designed for gaming. This is not surprising, considering that the manufacturer has always placed great emphasis on this. Therefore, we can enjoy both a properly implemented HGIG mode and gameplay in Dolby Vision with low latency. Such a tandem will surely attract the attention of all passionate gamers for whom quality is the most important.

A standard feature in televisions from the Korean manufacturer is also the implementation of GameBar, allowing for quick adjustments of settings "on the fly," without the need to exit the game. It also enables image adjustments for individuals with visual impairments, which is an extremely nice touch. Another important piece of information is that when the VRR technology is turned on, we will not experience a drop in contrast. This is, of course, due to the construction of the panel and the lack of conventional backlighting. However, it is normal for shades of grey to flicker slightly, although this is a characteristic feature of this function regardless of the manufacturer and the television.

In summary: The LG B4, like all OLEDs from the manufacturer equipped with 120Hz panels and HDMI 2.1 ports, creates a harmonious whole with the console. In practice, it is a complete television, and if we expect the highest possible efficiency in gaming, the B4 will be the ideal choice.

The TCL C6K is a television that can confidently be called equipment designed for gamers. We have 4K at 144 Hz, VRR support, an automatic gaming mode (ALLM), and Dolby Vision Gaming. On top of that, there's a practical Game Bar, which is a panel with the most important settings handy – useful when we want to quickly change something during gameplay (e.g. screen ratio: Yes, you can!). Notably, it has a wide range of VRR, reaching up to 240 Hz. However, this option is mainly for PC gamers who drop below the native 4K resolution. In that case, the television can spread its wings and show additional smoothness, especially in fast e-sport titles. For consoles, we stick with the classic limit of 120 Hz, but the possibilities are still quite broad. The only slight drawback is some minor motion blur that can occasionally be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a television.