LG 55 B4 vs TCL C6K

The HDR brightness performance of the LG B4 is impressive, even though it doesn't surpass 1000 nits. Its luminance stability is consistently strong across various scenarios, delivering a reliable viewing experience. The only instance where the TV shows slight weakness is in scenes with large areas of bright white, which has long been a challenge for OLED technology. However, perfect contrast, deep blacks, and excellent brightness ensure a fully immersive HDR experience. Furthermore, the TV’s remarkable 99% coverage of the DCI-P3 colour gamut enhances its colour vibrancy, making images appear rich and visually striking. This level of colour accuracy and brightness balance firmly places the LG B4 among the top choices for HDR content.

TCL C6K is a moderately bright TV that can showcase its full potential under the best cinematic conditions – the maximum brightness is around 600 nits. In scenes with large, intense light sources, the HDR effect can be really satisfying, providing a sense of cinematic brilliance. However, it should be noted that when managing the backlighting zones, there are situations where some elements become dimmed and sometimes can even become barely visible. It is clear that there is a lack of proper algorithm optimization here, although looking at the technical parameters in this price range, the design itself performs very well.

The best factory preset offered by LG B4 is the "Filmmaker" mode, which we used throughout our testing. Straight out of the box, the TV delivered fairly accurate colour reproduction. However, the most significant issue in both SDR and HDR content was the white balance. In SDR, there was a noticeable red dominance, giving the image a distinct yellow tint, particularly evident in skin tones and whites. In HDR, this red hue persisted, but the lack of blue also introduced a greenish tint in certain scenes. Additionally, we observed some inconsistencies in grayscale and colour accuracy. Despite these shortcomings, the overall picture quality was still solid for most viewing scenarios.

This year's TCL televisions feature a Filmmaker mode, and it must be admitted that it is definitely the best choice straight out of the box. This is the mode we recommend for everyday watching of movies and series. Unfortunately, as is often the case, the best doesn't mean perfect. In the case of SDR content, the image was too warm because the red was strongly emphasized 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 excess blue. Additionally, the brightness characteristic sometimes led to highlights being blown out. In practice, this resulted in quite noticeable color test inaccuracies that are hard to accept in a mode advertised as "by the creators."

LG B4 has long been known for offering advanced calibration tools, and it remains one of the few manufacturers that allows such in-depth image adjustments. Thanks to these tools, we calibrated the device to an exceptional standard. The result was incredibly low deltaE errors, considered at a reference level. Both SDR and HDR content now display exactly as the filmmaker intended. This level of precision is one of the reasons LG TVs are frequently used as preview monitors in graphic design and post-production studios.

Thanks to the white balance correction, it was possible to significantly reduce the C6K's tendency to distort colors, which resulted in a very good final outcome. After calibration, we will no longer 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, there are few complaints – the image looks really good, especially in older movies, TV shows, or materials from YouTube. This is much worse for HDR content. Analysis of the EOTF curve suggests that everything is fine, but in practice (EOTF in films), the limitations of the construction become apparent. The TV tends to overly brighten the smallest parts of the frame, and in other situations, it can dim the entire scene too much. The effect of calibration is therefore evident, and in terms of color, the C6K has gained quite a lot, but certain limitations arising from local dimming and, in fact, its management by the C6K simply cannot be overcome.

In this section, we will revisit the smooth transition function while also examining how the TV handles lower-quality content. As we’ve found, the setting responsible for smooth gradation is generally effective, though it does have its drawbacks. While the function works well in SDR content, it becomes less useful in HDR content. Even at the lowest setting, it can blur important details, so we advise against using it in such cases.

The image scaling on the LG B4 is assessed moderately positively. While there is no noticeable edge doubling, the image tends to be somewhat "soft." This can be adjusted by tweaking the sharpness slider to improve the clarity.

The TCL C6K performs quite well in terms of scaling. Lower quality materials look acceptable, and the lack of overscan issues means that the image is displayed in full, without cropping. However, one cannot expect miracles – content of very low quality will not gain new life here, as the image processor has its limitations. On thin lines or details, the characteristic tearing is visible, which reveals the absence of advanced image enhancement algorithms. It is also a pity that the C6K lacks the feature for smoothing tonal transitions – in older films or video materials, color banding can be noticeable and may be bothersome during long viewing sessions.

The maximum refresh rate on the LG B4 is 120 Hz, the bare minimum for those requiring high image fluidity. The manufacturer has equipped the TV with a multi-stage motion smoother called "TruMotion." This feature is split into two sliders: one controls the sharpness of moving images (De-Blur) and the other adjusts judder (De-Judder). Both sliders can be set between 0 and 10, with each level affecting the smoothness, so users can easily find their preferred setting.

The LG OLED B4 panel boasts an impressive average response time of 0.1 ms (based on our measurements), delivering an exceptionally clear image that surpasses the capabilities of LCD TVs, which often have response times of several milliseconds. This is particularly noticeable in the "UFO Test" images, where no trailing blur is visible behind moving objects.

TCL C6K features a 144 Hz panel, which is a significant advantage in this price range. This is an important step forward compared to the previous model C655 PRO, which offered only 60 Hz at 4K. The difference is especially noticeable when watching sports or playing games – the ball, athletes, or fast action in a game are displayed more clearly and without losing details. An interesting fact is also the ability of the panel to operate at 240 Hz, which the manufacturer does not mention in official materials. We will return to this topic when discussing the game mode for PC.

TCL also added a feature for movie watchers: "Motion Clarity," which allows you to adjust the image to your preferences using two simple sliders. You can keep the movie frame visible or opt for a very smooth, almost theatrical effect. This way, everyone can find settings tailored to their taste.

The LG B4 has four full HDMI 2.1 ports, each providing 48Gbps bandwidth. This ensures smooth activation of all relevant features without issues, making the television highly suitable for gaming. With its low input lag and extensive functionality, including well-implemented HGIG mode and Dolby Vision gaming with low latency, the B4 is a strong contender for gamers who demand high quality.

A standout feature is GameBar, which allows for on-the-fly adjustments without interrupting gameplay, as well as image adaptations for those with visual impairments. Another key point is that when VRR technology is enabled, the television maintains its contrast, thanks to the OLED panel's structure, though slight flickering in grey shades is to be expected.

In conclusion, the LG B4 is an ideal choice for gamers, seamlessly combining high performance with excellent gaming features. Its 120Hz panel and HDMI 2.1 ports make it a standout option for those seeking top-tier gaming experiences.

The TCL C6K is a TV that can confidently be called equipment designed for gamers. Here we have 4K at 144 Hz, VRR support, automatic game mode (ALLM), and Dolby Vision Gaming. Additionally, there's a practical Game Bar, a panel with the most important settings readily available – useful when we want to quickly change something during gameplay (e.g., screen aspect ratio: Yes, that’s possible!). The wide VRR range, reaching up to 240 Hz, deserves attention. However, this is mainly an option for PC gamers who drop below the native 4K resolution. Then the TV can spread its wings and show additional smoothness, especially in fast-paced e-sports titles. In the case of consoles, we stick to the classic limit of 120 Hz, but the possibilities are still quite broad. The only drawback is a slight ghosting that can sometimes be seen in dynamic scenes. Other than that, the C6K offers everything gamers expect from a TV.