LG 55 B4 vs TCL C6KS / C69KS / Q6CS

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.

And what about HDR? Here the C6KS performs quite well and – as is becoming the theme of this review – just like in the C6K model. The maximum brightness generated by this television is around 600 nits. In bright scenes, this translates to a really solid, cinematic effect and generally, video materials look good here. However, it's important to keep in mind the specifics of the dimming algorithm in this model. When very small, bright points (e.g. stars) appear on a dark background, the television can quite significantly dim them. The goal is simple: to eliminate blooming and maintain the best possible black. It's a reasonable compromise. Most viewers will definitely appreciate deep, “true black” more than additional microscopic details, the display of which could cause the screen to appear greyed out. Such is the nature of local dimming technology in this price range, and one must be aware of this. It’s also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the QLED technology slogan. Thanks to this, the colours are saturated and vibrant – our measurements showed that the coverage of a wide colour gamut reaches as much as 92%.

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.

In contrast to the more expensive C6K model, in the tested C6KS we don't find an option in the menu labelled as Filmmaker Mode. Is this a reason to cry? Absolutely not. Our tests showed that in practice, in terms of colour reproduction, the lack of this specific label makes virtually no difference. The best available Film/Cinema mode here offers an almost identical picture profile to the aforementioned Filmmaker in the more expensive model. So we get a very similar image, just under a different name. Therefore, if you were wondering whether paying extra for the C6K would give you better colours – the answer is: no, in both cases the base is the same and requires slight adjustments.

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, the C69KS's tendency to distort colours has been effectively limited, leading to a very good final effect. After calibration, we will no longer see excessive warmth in SDR scenes or overly cool tones in HDR. However, it is worth noting the brightness characteristic. In SDR content, there are hardly any objections – the image looks very good, especially in older films, TV shows, or YouTube materials. Evaluating the television's performance in HDR is much more difficult. Analysis of the EOTF curve suggests correct behaviour, but its practical variant shows certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times it can dim the entire scene. Calibration has therefore brought clear benefits in terms of colour, but certain limitations resulting from local dimming and the way it is controlled by the C69KS cannot be avoided, which we also observed in the C6K test.

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.

The C69KS handles upscaling quite well. The tested 576p content looks surprisingly decent – a considerable amount of detail is preserved, and the algorithm adds a subtle ‘rounding’ effect to sharp edges, making the image appear more cohesive. However, it doesn't perform as well when it comes to smoothing tonal transitions. The television practically cannot improve them, leaving the image in a rather raw state. With older materials, this can be simply exhausting, as the lack of additional processing highlights all imperfections.

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.

C69KS offers a simplified motion enhancement panel in movies, allowing users to adjust the intensity of the effect using a slider. This makes it easy to tailor the smoothness to personal preferences. It also deserves credit for the ability to utilise higher refresh rates – even though the panel operates natively in 4K at 60 Hz, by lowering the resolution to 1440p, modes of 120 and 144 Hz can be enabled, on both consoles and PC. This sounds like great news, however, in practice, the image at these settings trails exceptionally badly. The effect is so pronounced that the overall experience simply appears mediocre and loses its appeal in everyday use.

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.

If we overlook the smudging and lack of native 4K at 120 Hz, the C69KS is impressive in how well it performs for gaming. You get everything you would expect from a gaming TV: Variable Refresh Rate (VRR), Auto Low Latency Mode (ALLM), Dolby Vision Gaming mode, and a consistently functioning HGiG. The TV can also operate at 120 or even 144 Hz at lower resolutions, making gameplay on console or PC smoother. Additionally, there's a clear Game Bar that allows you to quickly check key settings while gaming. As a result — despite a few limitations — the C69KS can be a genuinely successful screen for gamers.