TCL C9K vs TCL C6KS / C69KS / Q6CS

As we mentioned regarding black levels and contrast – the C9K can make a huge impression in synthetic tests. Our measurements showed that on a screen 10% filled with white, the television can achieve... 4000 nits of brightness! It sounds out of this world, but – and here's where the pattern unfortunately repeats – the numbers say one thing, and the practical experience says another. In real movie scenes, the situation looks different. In the best-case scenario, when light effects occupy a large part of the image and the local dimming algorithm doesn't have to ponder too much about what to do with thousands of zones, the effect is really quite good. At that point, the C9K can hit around 1500 nits, which delivers a pleasant, intense burst and can indeed leave a positive impression.

The problem arises with smaller elements – such as stars in the sky, the moon, or individual reflections. That's when the proverbial cat comes out of the bag: the algorithms are not yet refined, and brightness drops to as low as 400–500 nits. That's a huge difference from the potential 4000 nits we saw in lab tests. Why does this happen? Most likely, the television is trying to protect the black levels in this way and minimize the halo effect around bright objects. Unfortunately, this comes at the expense of detail – some details simply vanish, and the scene loses its nature.

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%.

For colour tests, we once again reached for the Filmmaker mode – a new feature in TCL televisions for 2025. While the direction is a step in the right way, the execution leaves a lot to be desired. The white balance in SDR content turned out to be too warm – there was an excess of red. On the other hand, in HDR, it swung in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few colour inaccuracies that were noticeable to the naked eye. An even bigger problem turned out to be what we mentioned above – brightness management. Regardless of whether we were watching SDR or HDR content, the image tended to wash out the entire scene, giving it an unnatural, almost grotesque character. Therefore, it’s hard to call this a "director's mode" – because no director has ever seen such an image.

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.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colours finally started to look as they should, and the overall presentation was incomparably better than on the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is really significant. The gamma responsible for brightness management also managed to be brought into order in SDR content, and the effect was more than satisfactory. Unfortunately, when we turned on HDR materials, the situation quickly became complicated. No matter how we set the local dimming, the television had a tendency to do what it liked with the image – either it overexposed everything or darkened the darkest parts too much. Just like we saw in the scene from the movie Billy Lynn. Colour-wise, the improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of the C9K and presents a certain technological limitation.

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.

Digital image processing on the TCL C9K is rather average. The smooth tone transition feature seems to be present, but activating it practically changes nothing – colour bands are still visible, and it can unintentionally highlight elements we’d rather keep hidden, such as object textures. Fortunately, it doesn’t remove film grain, but that’s poor consolation given that the effects are still meagre. It’s therefore hard to recommend using this option.

On the other hand, image scaling presents itself much better. Lower quality materials look quite decent – characters and backgrounds are rendered clearly, although of course, with sources like 576p, the laws of physics cannot be fooled. Occasionally, there’s characteristic edge distortion of objects, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image isn't artificially cropped or enlarged.

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.

Similar to the C8K, the C9K is also a really fast TV – both figuratively and literally. It features a 4K panel with a refresh rate of 144 Hz, and at lower resolutions, the panel can even ramp up to 288 Hz. Such speed translates into practice – while watching sports or playing games, the image looks very smooth and clear. Additionally, in movies, we get an extra motion smoother called Motion Clarity, which allows you to adjust the smoothness to your own preferences – from cinematic "judder" to almost theatrical smoothness.

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.

From a gaming perspective, the TCL C9K is a complete tool. It features two (out of four) full bandwidth 48 Gbps HDMI 2.1 ports, so all the key technologies work: VRR (Variable Refresh Rate) and ALLM (Auto Low Latency Mode). Additionally, the manufacturer has included a really intuitive Game Bar that allows you to quickly check the most important parameters and adjust settings without fumbling through menus. Also, TCL's policy is a plus – the TV isn’t afraid of any HDR formats, even in game mode. Whether it's HGiG or Dolby Vision for the Xbox Series S/X console – everything works as it should, giving the player plenty of freedom.

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.