LG 55 B4 vs TCL C6KS / C69KS / Q6CS

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

And what about HDR? Here, the C6KS performs quite well and – as has become a recurring theme of this review – identically to 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, the video materials look good here. However, one must keep in mind the specifics of the dimming algorithm in this model. When very small, bright points (e.g., stars) appear against a dark background, the television can dim them quite significantly. The goal is simple: to eliminate blooming and maintain the best possible blacks. This is quite a reasonable compromise. Most viewers will definitely appreciate deep, "true black" more than additional micro-details, the display of which could cause the screen to appear greyed out. This is the nature of local dimming technology in this price range, and one must be aware of it. It is also worth noting that the TCL C69KS (C6KS) has an additional PFS coating, which is marketed under the slogan of QLED technology. 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% here.

The best factory mode prepared by the manufacturer is "Filmmaker," which is exactly what we used throughout the entire testing procedure. We must admit that the unit we received out of the box had quite good colour reproduction. The biggest problem in both SDR and HDR content turned out to be white balance. In the former, a strong red hue was evident, causing the displayed image to have a pronounced yellow tint, particularly noticeable on skin tones and whites. In higher quality materials, this colour was also accentuated, but due to a lack of blue, there were also signs of green visible. Apart from these issues, we also encountered problems with grayscale and the colours themselves.

Unlike the more expensive C6K model, the tested C6KS does not have an option in the menu labelled as Filmmaker Mode. Is this a reason to cry? Absolutely not. Our tests have shown 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 characteristic 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 gives 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 televisions for years. We can even say that as the only manufacturer on the market, it allows for such deep intervention in image adjustment. It is thanks to these tools that we were able to calibrate the device so well. Evidence of this is the extremely low deltaE errors, which can be said to be at a reference level. Both SDR and HDR materials now look exactly as intended by the film director. It is no coincidence that televisions 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, resulting in a very good final effect. After calibration, we will no longer see excessive warming of scenes in SDR or overly cool tones in HDR. However, it is worth noting the brightness characteristics. In SDR content, it is hard to have any objections – the image looks very good, especially in older films, television programmes, or materials from YouTube. It is significantly more challenging to evaluate the television's performance in HDR. Analysis of the EOTF curve suggests correct behaviour, but its practical variant reveals certain limitations. The C69KS can overly brighten the smallest elements of the frame, while at other times, it can dim the entire scene. Thus, calibration brought clear benefits in terms of colour quality, but certain limitations resulting from the local dimming operation and the way it is controlled by the C69KS cannot be overlooked, as we also saw in the C6K test.

In this paragraph, we will take another look at the function for smoothing tonal transitions, but we will also check how the television handles lower quality material. As we have managed to verify, the setting responsible for smooth gradation works quite efficiently, although it has its weaker moments. Just as the function works correctly in SDR content, it becomes rather useless in HDR content. Even at the lowest of the options, it blurs essential details, which is why we advise against using it.

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

The C69KS handles upscaling quite well. The tested 576p material looks surprisingly decent – a considerable amount of detail is retained, and the algorithm adds a slight "rounding" effect to sharp edges, making the image appear more cohesive. The performance in smoothing tonal transitions is less impressive. The television practically cannot improve them, leaving the image in a rather raw state. With older material, this can be quite tiring, as the lack of additional processing highlights any imperfections.

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

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 televisions, whose response times can be as high as several milliseconds. This is clearly evident in the pictures from the "UFO Test", showing no trail following the object.

C69KS offers a simplified motion enhancement panel in films, allowing the adjustment of effect intensity with a slider. This makes it easy to match fluidity to personal preferences. The ability to use higher refresh rates is also a plus – although the panel operates natively at 4K at 60 Hz, lowering the resolution to 1440p enables 120 and 144 Hz modes, both on consoles and PC. This sounds like great news, however, in practice, the image at these settings exhibits significant motion blur. The effect is so pronounced that the overall presentation appears merely average and loses its appeal for everyday use.

The LG B4 television is equipped with four fully-fledged HDMI 2.1 ports with a full bandwidth of 48Gbps. All features that are identical to this standard were activated without any issues, and throughout the entire testing process, they did not cause any problems. The combination of such extensive functionality and low input lag suggests that the tested television is truly made for gaming. This is not surprising, considering that the manufacturer has always placed great emphasis on this. Therefore, we can enjoy both the properly implemented HGIG mode and gaming in Dolby Vision with low latency. This pairing will certainly attract the attention of all passionate gamers for whom quality is paramount.

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

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

If we overlook the smudging and lack of native 4K at 120 Hz, the C69KS impresses with how well it performs during gaming. We get everything one can expect from a gaming television: variable refresh rate (VRR), automatic switching to game mode (ALLM), Dolby Vision Gaming mode, and a well-functioning HGiG. The television can also operate at 120 and even 144 Hz at lower resolutions, allowing for smoother gameplay on a console or PC. Additionally, there is a clear Game Bar that lets you quickly glance at key settings while gaming. As a result — despite a few limitations — the C69KS can be a really successful screen for gamers.