TCL C9K vs LG OLED G6 (G64LW, G66LS)

As we mentioned with black 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 is capable of squeezing out… 4000 nits of brightness! It sounds astronomical, but – and here, unfortunately, the pattern repeats – the numbers say one thing, and practice says another. In real movie scenes, the situation looks different. At best, when the light effects occupy a large part of the image and the local dimming algorithm does not have to think too hard about what to do with thousands of zones – the effect is really good. At that point, the C9K can reach around 1500 nits, which provides a pleasant, intense flash and can indeed make a positive impression.

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

The LG G6 is currently one of the brightest OLEDs on the market. Its peak brightness reaches nearly 2500 nits, and best of all – this has a direct impact on real film scenes. The television flawlessly pulls out details in the bright parts of the image. And this is regardless of whether we are talking about very small points like stars in the sky or slightly larger elements on the screen. Naturally, with full-screen, uniformly white scenes, the brightness of the G6 decreases due to the panel's protection system (ABL). However, in real, varied film shots, this value still hovers around 2000 nits, which can be considered an outstanding result. The coverage of the color palette also deserves praise. The new 2nd generation Tandem OLED panel brought only a cosmetic change, but still an improvement. The DCI-P3 color gamut coverage reaches nearly 99.5%, while the ultra-wide BT.2020 is around 84%. These are very good results, although one must remember one thing: at extremely high brightness levels, the volume of colors will be lower than in QD-OLED panels from Samsung Display due to the use of a white sub-pixel (WOLED). However, in everyday content and most films, detecting this difference will be very difficult.

For color tests, as always, we reached for the Filmmaker mode – a new feature in TCL TVs for 2025. And while the direction itself is a step in the right direction, the execution leaves much 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 went in the opposite direction: the image became excessively blue. The Colour Checker test revealed quite a few color errors 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 blow out the entire scene, giving it an unnatural, even grotesque character. It's hard to call this a "director-created" mode – because the director has certainly never seen such an image.

We tested the LG G6 in the best factory mode for color fidelity, which is FILMMAKER MODE. For our test unit, this mode was fairly well-tuned right out of the box. In SDR content, the only thing we could nitpick was the white balance, which leaned towards warmer tones. As a result, the image could sometimes appear slightly yellowed; however, overall, it wasn't a bothersome issue. The G6 performed a bit worse with HDR content. There, we noticed too much blue component in the white balance. This caused the image to take on cooler shades, resulting in quite noticeable errors. As can be seen in our ColorChecker chart, colors were indeed shifting towards these cooler registers. Nevertheless, for factory settings, the television displayed a completely decent level. However, we know that OLED screens – especially those from LG – respond wonderfully to professional calibration, which is why we immediately proceeded with it.

After calibration, we finally managed to tame the white balance – and it immediately translated into a more natural image. Colors finally started to look the way they should, and the overall presentation was incomparably better than in the factory settings. In other words – it’s worth taking a moment to improve this, as the gain is truly significant. The gamma responsible for managing brightness was also brought into order in SDR content, and the effect was more than satisfying. 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 dimmed the darkest parts too much. Exactly as we saw in the scene from the movie Billy Lynn. So, the color improvement after calibration makes a great impression, but brightness management in HDR remains the Achilles' heel of C9K and presents a certain technological limitation.

After conducting a professional calibration, we gained complete control over the panel, and we were able to adjust all parameters to nearly zero. We managed to perfectly tune the white balance, which made the factory-cool and warm tints disappear from the screen. The effects are clearly evident in the ColorChecker test – the average color reproduction errors dropped below the critical value of 1-2. And what does that mean? PERFECT colors, with no distortion whatsoever! However, from a reviewer's obligation, we must comment on how the LG G6 autonomously manipulates brightness, for which the EOTF curve is responsible. When we look at the standard synthetic graph, it may seem that the line is quite straight. The situation changes, however, when we turn on the measurement filter, which shows how the television interprets brightness in real, moving film scenes (EOTF in MOVIES). At that point, it becomes clear that some of the smallest fragments on the screen are slightly over-brightened by the algorithm. Of course, for the average viewer, such a deviation will be practically unnoticeable, but in the test of such an expensive screen, it is worth noting – especially since we are talking about a model that has huge aspirations to be the best television of the year.

Digital image processing in TCL C9K is quite mediocre. The tonal smoothing feature seems to be present, but turning it on practically changes nothing – color bands are still visible, and it can unintentionally highlight elements we would prefer to hide, such as textures of objects. Fortunately, it doesn’t remove film grain, but that’s small comfort since the effects are still poor. Therefore, it's hard to recommend using this option.

On the other hand, image scaling performs much better. Lower quality materials look quite decent – characters and backgrounds are presented clearly, although, of course, with sources at 576p, physics cannot be fooled. Sometimes, characteristic aliasing on objects appears, but that’s the fault of the source itself, not the algorithm. A plus for not having issues with overscan – the image is not artificially cropped or enlarged.

No matter what one may say about the G6's problems with near-black signal, it must be fairly acknowledged that it handles highly compressed material and lower resolution content brilliantly. All unwanted, ugly tonal transitions are effectively reduced here by the “Smooth Gradation” feature. On the “Low” setting, the algorithm operates flawlessly – effectively masking the artifacts resulting from strong compression, without destroying the sharpness and details in the frame. Higher levels of this feature indeed smooth the image even more, but they start to blur the real texture elements of objects, which is why we recommend keeping this slider at a low level. As for the upscaling to 4K, the processor does an excellent job – edge sharpness and detail reconstruction are at the highest level, and in this respect, the G6 does not lag behind the world's best.

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

The LG G6 is an OLED television, so in the category of motion fluidity, it traditionally deserves the highest ratings. The television supports a very high refresh rate of up to 165 Hz in 4K resolution, but most importantly – you will not see any signs of blurring on the screen. The response time of the panel is incredibly fast, ensuring that dynamic images remain perfectly sharp.

For gaming, the TCL C9K is a complete tool. Here we have two (out of four) HDMI 2.1 ports with full bandwidth of 48 Gbps, so all key technologies work: VRR (variable refresh rate) and ALLM (automatic low latency mode). Additionally, the manufacturer added a really intuitive Game Bar, which allows you to quickly preview the most important parameters and adjust settings without digging through the menu. Also, TCL's policy is a plus – the TV is not 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 wide freedom.

LG G6 is a true monster for gamers and one of the best-equipped TVs in this regard on the market. The manufacturer did not seek compromises and equipped this model with as many as four full HDMI 2.1 ports with a maximum bandwidth of 48 Gbps. This means that no matter which port you plug your PlayStation 5, Xbox Series X, or powerful PC into, you will extract the absolute maximum from them.

The TV supports a full suite of gaming technologies: from VRR (Variable Refresh Rate), through AMD FreeSync Premium Pro, to Nvidia G-Sync Compatible. Let's add to this the remarkably low, almost imperceptible input lag and a brilliantly functioning gamer panel (Game Optimizer), which allows you to continuously monitor the signal parameters. Gaming on this screen, with the perfect black of OLED and powerful refresh rates, is pure pleasure.