TCL A400 PRO vs Samsung S90H (WOLED)

The TCL A400 Pro is a moderately bright TV. Its peak brightness reaches around 600 nits. That level already allows for a real HDR effect and in many films it does deliver a noticeably more appealing picture than in SDR. However, it’s not a level that dazzles by brightness alone. The A400 Pro is not one of those TVs that bombard the viewer with a powerful flash in every dramatic scene. The biggest limitation is visible with small bright elements on a dark background. Because of fairly aggressive zone control, 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. It should be added, though, that this isn’t done without reason. The A400 Pro does this to keep black levels as deep as possible and to limit the halo effect around bright objects. It’s a deliberate compromise: the TV more often opts for deeper blacks rather than maximising point highlights. On the one hand this is understandable, especially given a limited number of dimming zones, but on the other you should be aware that the HDR effect won’t always be as strong as the peak brightness alone might suggest.

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

The Samsung S90H in the WOLED variant is still an exceptionally bright TV for its price bracket, although it is slightly dimmer compared with the QD-OLED version. That difference is not as pronounced as in last year’s F series, where gaps sometimes reached 500 nits. Here the parameters of both panels are very similar, with differences in peak brightness of only about 100–150 nits. In small-window measurements the S90H with the WOLED panel easily reaches close to 1,500 nits. That headroom lets it phenomenally convey the dynamics of HDR effects — blooms, light reflections and explosions have the right punch, exactly as intended by the studio creators. As with most OLED displays, when a very bright scene fills the entire screen, panel protection systems kick in and brightness naturally falls to around 700 nits. It’s worth stressing that this is still an excellent result on the market, often noticeably better than many Mini LED screens in the same segment.

Colour gamut coverage

The biggest difference between the two S90H variants lies in colour reproduction and saturation. This stems directly from the different construction of the WOLED panel, which uses an additional white subpixel. As a result, very high-brightness colours don’t achieve quite the same saturation, and the wide-colour volume is slightly more limited than with QD-OLED. That said, in everyday use these differences will be hard for most viewers to notice. Our measured DCI-P3 coverage on the WOLED panel reaches almost 99%, meaning that for the vast majority of real film scenes both variants will present an almost identical image. The real gap only appears in rarer, especially demanding productions that use the ultra-wide BT.2020 gamut. Because of the WOLED panel’s construction, coverage of that standard is roughly 15% lower compared with the S90HAT with a QD-OLED panel, so the brightest, heavily lit HDR colours may appear a touch less vivid.

As usual, we carried out colour measurements in the best‑tuned picture mode, Filmmaker Mode, the one intended to be closest to the creators’ intentions. The A400 Pro, of course, also offers other picture modes, but in practice they show much larger colour errors and interfere more with the image character. So we won’t cover them in detail in this part of the review. How does the factory colour reproduction fare? In short: really very well. In fact, looking at our measurements, it’s excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during the measurements we genuinely rubbed our eyes in surprise. Such good factory settings don’t happen often, even in televisions running Filmmaker Mode. All the more reason to praise TCL, because the A400 Pro straight out of the box can produce an image very close to how the source material should look. The results were so good you could easily think someone had already given this unit extra attention and tried to calibrate it. Our one bit of nitpicking comes down to a single issue. In SDR material the image was slightly brighter than the reference for a dark room, because the factory gamma was set closer to 2.3 than 2.4. It’s not a large error and most viewers probably won’t even notice it. We should note, however, that we are talking about our specific test unit. There can always be some variation in factory colour between individual units, production batches or screen sizes. We do not assume every A400 Pro will look identical straight out of the box.

In Filmmaker mode, which we strongly recommend switching on straight out of the box, the S90H offers very good factory colour tuning. Colours are natural and faithful to the creators' intent, without the annoying oversaturation seen in more aggressive profiles. However, as is often the case without full calibration, there is unit-to-unit variation. In our test the white balance was a little deficient in the blue component, so the image leaned slightly towards warmer, yellowish tones. This was most noticeable in bright scenes, such as the snowy sequences from Star Wars. Additionally, the gamma curve was slightly low at around 2.2, which caused a small lift in shadow detail. In HDR mode the tuning was a bit better, showing only a slight undersaturation in the red region.

Despite the outstanding factory tuning, we couldn't resist checking how the TCL A400 Pro would respond to professional calibration. With such a strong starting point, we were especially curious whether we could squeeze even more from this TV. And here we have to boast: we managed to bring our sample to absurdly low colour errors. Results below 1 are something you don't see every day, even on very good TVs. Such outcomes are more often associated with professional reference monitors than with a lifestyle TV for the living room. In terms of white balance and colour reproduction, the A400 Pro after calibration simply excelled. The only thing we can pick on after closer analysis concerns the brightness response. The TV can vary the luminance level depending on the content being displayed, and quite often the picture is a little darker than it should be according to the reference. This most likely stems from the way the Mini-LED backlight and the local dimming algorithms work in this model. That said, it doesn't ruin the overall impression, because in terms of colour precision the A400 Pro after calibration reached a level that was genuinely hard to expect.

After full calibration, you can safely say the S90H in the WOLED version looks almost perfect. In SDR mode colour errors fall to ultra-low levels and Delta E values very rarely exceed 2. That's a phenomenal result, so if perfectly faithful colour reproduction matters to you, it's definitely worth getting it calibrated. The calibrated HDR mode also performs very well, where the white balance was stabilised and previous deviations eliminated. After professional tuning it's really hard to fault anything, because the TV delivers an image with almost exemplary naturalness and three-dimensionality. The slightly lower score in this category compared with the QD-OLED variant is solely due to the saturation limitation in extremely bright scenes, while the tuning potential and colour fidelity are at the highest level.

Digital image processing is unfortunately one of the weaker points of the TCL A400 Pro. That does not mean the TV performs badly, but it’s hard to call it anything clearly above standard. The upscaling itself is acceptable: edges are fairly well smoothed, the picture does not look overly sharp or “pixelated”, and lower-quality material can be watched without major discomfort. At the same time the overall image has a slightly soft character and you don’t see the kind of precision that the best image processors in more expensive TVs can offer.

Handling of tonal transitions caused by heavy compression is much worse. TCL equipped the A400 Pro with a “Gradual Smoothing” feature that in theory should reduce visible colour banding and artefacts in lower-quality material. In practice, however, its effectiveness is very limited. It does not improve tonal transitions in any noticeable way, and at higher settings it can further smooth image detail, giving it an artificial, slightly blurred character. For that reason we think it’s best to leave this feature off. The A400 Pro copes decently with basic image scaling, but if you often watch heavily compressed material with visible posterisation, this model will not be one of the best choices.

When it comes to banding reduction itself, Samsung has kept the same solutions known from last year’s models. The dedicated gradient-smoothing function works quite well and can effectively mask unwanted tonal transitions, which can be useful on a WOLED panel that’s somewhat more prone to banding. However, it’s important to remember it acts aggressively. This mechanism, aside from the artefacts themselves, can remove fine film grain and subtly soften detail. Ultimately it’s a trade-off, but if you want perfectly faithful image reproduction, it’s safer to leave this option off.

There’s also no breakthrough in scaling. The S90H uses the same NQ4 Gen3 processor as its predecessor, so upscaling quality was almost identical. The chip sharpens lower-resolution material very well, pulling a satisfying level of detail out of it. However, Samsung still hasn’t solved the old overscan problem. For some older recordings or archival footage the edges of the image can be slightly cropped. It’s a minor drawback, but it’s a shame the manufacturer still hasn’t fixed it.

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 most consoles, as well as many sports broadcasts and high-motion sources, are limited to today. In that range the TV performs quite well. Motion clarity is really good, especially after properly configuring the motion smoothing. The 'Motion Clarity' function improves smoothness. Its settings include two sliders that let you tailor the motion smoothing to your preferences, separately for low-frame-rate and high-frame-rate content. This allows you to achieve either a more cinematic look or a noticeably smoother image. If you don't want to fiddle with manual configuration, you can use built-in presets such as Low, Medium, High, Cinema or Nature.

When it comes to motion handling the S90H is simply excellent. This year's panel offers its refresh rate boosted to 165 Hz, although in practice the benefit will mainly be for gamers connecting a powerful PC. For movies, TV series or sports broadcasts such a high refresh rate makes no difference and the picture looks exactly the same as at the standard 120 Hz. Regardless of the source, the OLED panel's lightning-fast response time does the job. Motion is clean, and the ghosting or smearing seen on LCDs simply doesn't occur here.

In terms of gaming features the TCL A400 Pro performs brilliantly. The TV has practically everything you’d expect from a gaming TV today: support for 4K at high refresh rates, VRR, ALLM, correct implementation of HDR formats in games, including Dolby Vision, and HGiG. That means it works well with both next‑gen consoles and PCs. Another plus is the inclusion of a Game Bar, a dedicated panel with the most important settings for gamers. From it you can quickly check basic information about the signal, refresh rate or active features, and customise the appearance and behaviour of some settings to your preferences. It’s 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 criticise 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 serves as eARC. In practice this means that if you want to connect two next‑gen consoles and a soundbar you may run into some limitations. In that scenario you’ll need to either swap devices or use extra equipment, such as an AV receiver or a soundbar with HDMI inputs. Even so, it’s hard not to rate the A400 Pro very highly as a gaming TV. The gaming feature set here is genuinely powerful.

Gamers should feel right at home with the S90H, because Samsung has left few reasons to complain in this area. The TV has four HDMI 2.1 ports, each supporting VRR, ALLM and high refresh rates. There's also the Game Bar, a handy menu that lets you quickly check key parameters and change settings without leaving the game. Importantly, Samsung has also improved HGiG. In last year's models it could cause issues when used with a console, but on the S90H it now works as it should. What really stands out against the competition is Game Motion Plus. It's a specialised motion-smoothing mode for games that works best with titles running at 30 or 60 frames per second. Motion becomes noticeably smoother and latency remains at a reasonable level. In our measurements it was under 50 ms, so gaming is still comfortable. That's important, because on many TVs enabling a similar smoothing feature causes such a big increase in input lag that controls become noticeably sluggish. Samsung has managed to find a good compromise here. There's still no Dolby Vision Gaming, but in practice Game Motion Plus may prove to be the more useful feature.