TCL A400 PRO vs Samsung S90H / S92H (QD-OLED)

The TCL A400 Pro is a moderately bright TV. Its peak brightness reaches about 600 nits. That level already allows for a real HDR effect and in many movies it does produce a noticeably more attractive picture than SDR. However, it is not a level that overwhelms by brightness alone. The A400 Pro is not one of those TVs that "attack" the viewer with a powerful flash in every dramatic scene. The biggest limitation is visible with small bright elements on a dark background. Due to rather aggressive control of the dimming zones, the TV can significantly reduce their brightness — in extreme cases down to around 100 nits. That means small lights, sparks, stars, or single highlights can be much less visible than they should be. That said, this is not done without reason. The A400 Pro does this to keep blacks as deep as possible and to limit haloing around bright objects. It's a deliberate compromise: the TV more often chooses deeper blacks over maximally bright, point-like highlights. On one hand this is understandable, especially with a limited number of dimming zones, but on the other hand you should be aware that the HDR effect will not always be as strong as the peak brightness alone would suggest.

On the plus side, the colors are worth noting. The PFS LED filter used here, marketed by the manufacturer as QLED, produces suitably saturated colors. Our measurements showed about 94% coverage of the DCI-P3 gamut and about 74% of BT.2020, which is a solid result for this class.

The Samsung S90H is a truly bright TV for the midrange among OLEDs. In synthetic measurements its peak brightness reached about 1650 nits. That's an outstanding result in this class, roughly 50% higher than what we’ve seen from previous models at this price point. Crucially, these tests translate directly to real video material. In 4 out of 5 film shots we tested the S90H’s brightness hovered around 1300–1500 nits. That headroom lets the TV reproduce most HDR movies with the same dynamics and expression the creators intended in post-production. Of course, on full-screen, very bright scenes the result is naturally lower and drops to around 900 nits. That’s a direct result of the protection systems that prevent the OLED panel from being overloaded. Even in that scenario there’s no reason to complain. Those 900 nits across the entire screen is still a very high level, ensuring excellent dynamics in HDR content.

A major advantage of QD-OLED TVs has always been color, and the S90H is no exception. The DCI-P3 gamut we measured reached a full 100% (exactly 99.9%), while coverage of the much wider BT.2020 gamut hit roughly 89%. That’s a great result, allowing you to enjoy extremely saturated, vivid colors in HDR content. It’s worth noting these figures are better than WOLED panels, which is especially noticeable in very demanding film scenes.

As standard, we carried out color measurements in the best-calibrated mode, Filmmaker Mode, the one that is supposed to be closest to the creators’ intent. The A400 Pro, of course, also offers other picture modes, but in practice they suffer from much larger color errors and alter the image character more strongly. We won’t go into those modes in detail in this part of the test. So how does the factory color reproduction perform? In short: really very well. In fact, looking at our measurement results, it’s excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during testing we genuinely rubbed our eyes in disbelief. Such good out-of-the-box settings don’t happen often, even in TVs operating in Filmmaker Mode. All the more reason to praise TCL, because the A400 Pro right out of the box can produce an image very close to how the source material should look. The results were so good that you could easily think someone had already paid extra attention to that unit and tried to calibrate it.

Our nitpicking really comes down to just one thing. In SDR content the image was slightly brighter than the reference for a dark room, because the factory gamma was set closer to 2.3 than to 2.4. It’s not a big error and most viewers probably won’t even notice it.

However, it should be noted that we’re talking about our specific review sample. With factory colors there can always be some variation between units, production batches, or screen sizes. So we don’t assume that every A400 Pro will look identical straight out of the box.

The next stage of the test was to check how the S90H handles color reproduction without any calibration. As always, we took measurements in Filmmaker Mode, the best out-of-the-box picture setting. And here Samsung truly deserves praise. The factory tuning is at a very high level, and a few years ago that wasn't one of its strong points. The white balance was set correctly, as was the brightness response. The average color error (Delta E) hovered around 3, which is below the level at which most people can notice inaccuracies. Only in the brightest shades of gray did values slightly approach 4, but it's still hard to consider that a real viewing issue. For settings straight out of the box, the result is simply excellent.

Despite its excellent factory tuning, we couldn't resist checking how the TCL A400 Pro would respond to a professional calibration. Since the starting point was so good, we were even more curious whether we could squeeze even more out of this TV. And here we have to boast: we managed to bring our unit to absurdly low color errors. Results below 1 are something you don't see every day, even on very good TVs. Such results are more often associated with professional reference monitors than with a lifestyle TV for the living room. In terms of white balance and color reproduction, the A400 Pro after calibration simply performed outstandingly. The only thing we can pick at after a deeper analysis concerns the brightness behavior. The TV can manipulate luminance levels depending on the content being displayed, and quite often the image is a bit darker than it should be according to the standard. This most likely stems from the way the Mini-LED backlight and local dimming algorithms work in this model. However, that doesn't spoil the overall impression, because in terms of color precision alone the A400 Pro after calibration reached a level we really didn't expect.

Okay, but you know we wouldn’t be ourselves if we didn’t check how much more we could squeeze out of the S90H with professional calibration. And there was no big surprise here: since the out-of-the-box settings were already very good, there wasn’t a huge reserve. Even so, we managed to refine the picture almost to perfection. After calibration the average color reproduction errors fell below the threshold of perception, reaching Delta E values under 2 for both SDR and HDR material. We also improved the brightness response, so the image more faithfully reflects the creators’ intent and maintains proper tonality across the full brightness range. Not necessarily, because the factory settings already deliver a very high level. If you want the most accurate image and want to squeeze absolutely everything out of this panel, the S90H offers that potential. After professional calibration it’s simply an almost reference display.

Will the difference be spectacular for everyone? Not necessarily. It depends a lot on the individual unit. Our sample was very well tuned straight out of the box, but that doesn’t mean every S90H will perform at the same level. Even identical models can vary in their factory calibration. That’s exactly why professional calibration makes sense: it lets you bring a specific unit to the highest possible accuracy instead of hoping for a bit of luck when buying.

Digital video processing is unfortunately one of the weaker points of the TCL A400 Pro. That doesn't mean the TV performs badly, but it's hard to call it anything clearly above standard. The upscaling itself is adequate: edges are smoothed fairly well, the image doesn't look overly sharp or pixelated, and lower-quality content can be watched without major discomfort. At the same time the overall look is slightly soft and it lacks the precision that the best image processors in more expensive TVs can deliver.

Much worse, however, is its handling of tonal transitions caused by heavy compression. TCL equipped the A400 Pro with a "Gradual Smoothing" feature that in theory should reduce visible color banding and artifacts in lower-quality content. In practice its effectiveness is very limited. It does not improve tonal transitions in any noticeable way, and at higher settings it can also smooth out image details, giving the picture an artificial, slightly blurred character. For that reason we think it's best to leave this feature off. The A400 Pro handles basic image scaling decently, but if you often watch heavily compressed content with visible posterization, this model won't be one of the best choices.

In this regard Samsung has practically changed nothing compared with last year’s model, which is actually pretty good news. The function responsible for smoothing tonal transitions still very effectively reduces posterization. You should remember, however, that it works quite aggressively, because besides removing artifacts it can also eliminate film grain and slightly soften fine image details. As always, it’s a matter of compromise and personal preference. If you want the most faithful reproduction of the source, we recommend leaving this function turned off.

There’s also no revolution when it comes to upscaling. The S90H uses the same proprietary NQ4 Gen3 image processor as its predecessor, so scaling quality has remained virtually unchanged. The TV handles lower-resolution content well, effectively improving sharpness. The overscan issue still hasn’t been solved, though. With some older material, especially archival footage, parts of the image at the edges may be cropped. It’s a minor flaw, but it’s a shame Samsung left this problem unchanged for another year running.

The TCL A400 Pro is equipped with a 144 Hz panel, but in practice we're most interested in how it performs at 120 Hz. That's the refresh rate used by most consoles today, as well as many sports broadcasts and high-frame-rate content. In this range the TV performs quite well. Motion clarity is really good, especially after properly configuring the motion smoothing. The "Motion Clarity" feature improves smoothness. Its settings include two sliders that let you tailor the motion smoothing to your preferences — separately for lower- and higher-frame-rate material. That way you can achieve either a more cinematic look or a noticeably smoother picture. If you don't want to tweak settings manually, you can use presets such as low, medium, high, cinema, or nature.

In terms of motion smoothness, the S90H delivers a very high level. New here is a panel with a 165 Hz refresh rate. In practice, when watching movies or sports broadcasts it's hard to notice any difference, because that kind of content doesn't use refresh rates higher than 120 Hz. The extra 165 Hz will be appreciated mainly by PC gamers who can generate that many frames per second. Samsung equipped the TV with advanced motion settings. You get two sliders (judder reduction and blur reduction) that make it easy to tailor the picture's character to your preferences. You can easily get very smooth motion for sports, but you can just as easily preserve a more cinematic feel with the typical 24 fps. It all depends on which effect you prefer.

When it comes to features for gamers, the TCL A400 Pro performs excellently. The TV has practically everything you can expect from a gaming TV today: 4K support at high refresh rates, VRR, ALLM, correct implementation of HDR formats in games, including Dolby Vision, and HGiG. Because of that it works well with both next-gen consoles and PCs. Another plus is the inclusion of a Game Bar, a special panel with the most important settings for gamers. From it you can quickly check basic signal information, refresh rate, and active features, and also adjust the look and behavior of some settings to your own preferences. This is a solution that may not change picture quality by itself, but it greatly improves the convenience of using the TV while gaming.

The only thing to complain about is the number of full HDMI 2.1 ports. The A400 Pro has only two such ports out of four, and one of them also functions as eARC. In practice this means that if someone wants to connect two next-gen consoles and a soundbar, they may hit some limitations. In that scenario you'll have to either swap devices or use extra equipment, for example an AV receiver or a soundbar with HDMI inputs. Despite this, it's hard not to rate the A400 Pro very highly as a gaming TV. The gaming feature set here is really powerful.

From the start the Samsung S90H feels like a TV designed with gamers in mind, and honestly... it's hard to blame them. The manufacturer equipped it with everything you’d expect from a gaming TV. You get four full-bandwidth HDMI 2.1 ports, support for ALLM and VRR, and very high refresh rates. There’s also a clear Game Bar that lets you quickly check key picture parameters or change settings without leaving the game. Another very welcome improvement is that HGiG now works properly. Last year it could cause a lot of issues, but on the S90H it behaves exactly as it should.

Samsung’s real ace, however, is its proprietary Game Motion Plus mode. The feature works similarly to the motion smoothing known from movies, improving animation smoothness in games while keeping input lag at a very reasonable level. For titles running at 30/60 fps, with the right settings, input lag did not exceed 40 ms in our tests. That’s a very good result, especially since enabling similar features from many manufacturers can end up increasing lag three to four times. It’s a feature that partly makes up for the lack of Dolby Vision Gaming. A smoother image often provides more noticeable benefits than the HDR format itself, so for many gamers this will be a far more valuable addition.