TCL C9K vs Hisense U7S / U77SE

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 Hisense U7S has considerable HDR potential, but it can't use it in every scene. On a test pattern it reaches around 1,100 nits, so the backlight itself is very strong. In our brighter film scenes we measured about 640 to 745 nits. That's still enough for the sun or bright highlights to have a noticeable glow and to show an advantage over SDR material. When the TV needs to illuminate a larger portion of the image, it does quite well.

The problem appears with small lights on a dark background. Each of the 192 zones covers an area much larger than a tiny point on the screen. If the TV were to strongly light such a zone, it would also brighten the surrounding area along with the light. Hisense tries to avoid that and dims the entire zone. Black levels therefore look better, but a small bright object that should draw the eye also loses intensity. That's why in two tougher scenes we recorded only 297 and 154 nits. The difference is large: in one shot HDR can impress, and in the next small lights are noticeably muted. The U7S therefore prioritizes maintaining deep blacks, even at the expense of bright details. With this number of zones that's an understandable compromise, but it's worth remembering — the 1,100-nit peak tells us about the backlight's capability, not how brightly the TV will render every element of a film.

Colors

Hisense calls the U7S ULED, but that's a marketing name; the wider color gamut here comes from a PFS phosphor backlight. In our measurements the TV covered about 91% of DCI-P3 and 71% of BT.2020. Those are good results, although it falls short of the best screens on the market. The biggest shortfall is in green — the TV doesn't even reach the DCI-P3 target there, so the most saturated shades will be less intense than they should be. Most colors in HDR films and series, however, still look suitably rich. A positive is the repeatability of the results. Gamut coverage on test patterns and in film scenes is practically identical.

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.

The out-of-the-box colors on the Hisense U7S are decent, but there are a few things to improve. In SDR there's a red bias in the white balance, which makes the image too warm and in places slightly pink. You can notice this on faces and on bright, neutral surfaces. Gamma also runs below the reference, so the TV brightens the image, especially in darker areas. That makes shadow details easier to see, but the scene loses some of its depth.

In HDR the white balance is a bit more even, but not completely neutral; midtones lack blue, and the brightest areas lack red. A bigger problem is how brightness is reproduced. The EOTF curve shows that a large portion of midtones is being brightened, so the image looks brighter than the source material intends. Color Checker measurements also perform worse than in SDR: many errors are around 3 to 4, and individual ones reach as high as 8. Colors can therefore look attractive, but they are not always faithful to what we should be seeing. There's room for improvement, and we'll check how much can be corrected with calibration.

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.

Calibration of the Hisense U7S helped most with SDR content. We managed to even out the white balance, so the previous warm cast is gone and whites and grays look neutral. Gamma is also now very close to the reference, and the TV no longer brightens the image unnecessarily, so darker scenes have regained depth. Color Checker measurements confirm the improvement: most errors fall below 2. That yields a really well-calibrated picture for regular TV and SDR movies. It didn't go as smoothly in HDR. The TV lacks an effective way to correct the EOTF curve, so Hisense still interprets the content's brightness a bit on its own. It brightens parts of the image and can dim the brightest elements depending on the scene and the local dimming behavior. Calibration couldn't eliminate this. It shows up in the Color Checker results as well, where many errors remain around 3–4 and individual ones exceed 7. So in SDR the result is very good, but in HDR we have to accept that the TV adds its own interpretation of brightness to the image.

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.

The handling of lower-quality material on the Hisense U7S is fairly mediocre. The Pentonic 700 chipset used here doesn't cope well with the effects of heavy compression. The menu includes a "Smooth & Gradient" picture option, but its performance leaves much to be desired. At the low setting it's hard to notice any improvement in tonal transitions, although at least the image isn't degraded. The medium and high settings still don't remove visible banding between shades and begin to smear details; in our test clips even parts of characters' faces disappeared. Interestingly, film grain remains untouched at every level. If you use this feature, we'd stick with the low setting. Its current behavior needs refinement, but that's mainly down to the processor used. Upscaling to 4K performs much better. Lower-resolution footage gains clarity, edges are well reconstructed, and fine elements look crisp. That doesn't mean it can recover details that weren't in the recording, but the TV makes good use of what it gets from the source. Another plus is that it doesn't crop the image edges, even with an SD signal.

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.

Motion handling on the Hisense U7S is pretty good thanks to the 144 Hz refresh rate. For movies we also have a motion smoothing feature that lets you adjust judder and blur reduction. You can therefore keep a more cinematic motion or increase smoothness if abrupt camera shifts bother you. In sports and games the high refresh rate is also useful, but unfortunately it doesn't solve this panel's biggest problem.

The culprit is pixel response time. Fast-moving objects leave long, noticeable trails, as our UFO test shows. It's worst on dark backgrounds, where the trail behind the object is especially pronounced. So motion can be smooth, but the moving object itself loses sharpness, and that difference on the U7S is fairly easy to notice.

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.

The Hisense U7S has a lot to offer gamers. You get two HDMI 2.1 ports and support for 120 Hz at Full HD, 1440p, and 4K, so modern consoles’ capabilities are well used. When connected to a PC you can use 144 Hz at 4K or switch the resolution to Full HD and run 240 Hz. So there’s a wide choice, although it’s worth remembering the motion smearing mentioned earlier, which the high refresh rate does not eliminate. VRR and ALLM are also present. The first helps prevent tearing when frame rates in a game change. The second automatically switches the TV into game mode, so you don’t have to dig through the menu each time. VRR works from 48 to 240 Hz, with the highest refresh rate available in Full HD. Xbox users can also play in Dolby Vision, including at 120 Hz. Importantly, this format does not introduce significant input lag here. The Game Bar also looks very good. It’s easy to read, visually appealing, and lets you quickly check what signal the TV is receiving. There are also handy gaming settings at your fingertips, including shadow brightening. If it’s hard to spot an opponent in a dark game, you can improve visibility without digging through the entire menu.

Our biggest complaints concern HGiG. Hisense continues to do its own tone mapping, which makes setting HDR on the console confusing. You adjust a checkerboard test pattern and the TV continuously adapts how it looks. As a result, the moment the pattern disappears does not correctly indicate the screen’s brightness limit, and it’s easy to set the value too high. For this model it’s better to set the target HDR peak brightness on the console to about 900 to 1000 nits, rather than relying on the configurator.