TCL A400 PRO vs Philips OLED811

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.

Philips OLED811 uses the new generation WOLED EX panels, also found in models like the LG C6 and Samsung S90H. After calibration we measured around 1500 nits, which is a very good result for an OLED TV. You can see it clearly in movies and series. All kinds of light flashes have the right intensity, especially when they appear on a dark background. In such scenes the OLED811 can deliver truly impressive HDR. Of course, that doesn't mean you'll see that peak brightness in every shot. When the screen is filled with a large area of white or a big explosion, brightness falls to around 600 nits. That's still a good result, but those scenes no longer have the same punch as small, bright elements on a dark background. This is a known limitation of OLEDs, and the OLED811 is no exception.

Colors

Aside from HDR brightness, colors also matter, and Philips performs very well here too. It covers almost the entire DCI-P3 gamut, which contains most of the colors used in HDR movies and series. So you get rich reds and lush greens, and while watching it's hard to find major faults in this area. It looks a bit worse with the much wider BT.2020 gamut — its most saturated shades are already beyond the reach of this panel. Added to that is the issue of the white subpixel the WOLED panel uses to help boost brightness. With very bright colors you can see some "whitening": the color is bright but loses some of its saturation. In exactly these situations QD-OLED panels from Samsung Display have the advantage. In most movies and series, however, this won't be something that immediately stands out.

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 movie mode on the Philips OLED811 is sensibly configured right out of the box. Most color errors are minor, both in SDR and HDR, so you can sit down and watch without first adjusting the settings. There are no major inaccuracies that would immediately pull attention away from the film.

It's not perfect, though. The white balance shows a slight deficiency of red compared with green, so whites and grays can have a faint greenish tint. It's not a strong cast, but measurements clearly show it. There are also small brightness deviations in SDR: some areas of the picture are slightly lifted, and the deepest blacks aren't always rendered evenly. In HDR the TV tracks the reference much more closely, although in places it slightly pulls details out of the shadows. These are generally things to refine. The factory movie mode provides a good starting point, and calibration will show how much more you can get out of it.

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.

After calibration the Philips OLED811 produces an image very close to the reference. We managed to even out the white balance and remove the subtle color cast visible in the factory settings. Errors in Color Checker measurements for SDR and HDR dropped to around 1 to 2, and many samples even fall below 1. That's a level at which it's hard to spot differences from the reference image with the naked eye. We also improved the gamma, and only in the brightest whites a slight brightening remains. In HDR the EOTF curve also stays close to the reference, although the TV still tends to slightly boost the brightness of small elements like stars or subtitles. That gives the image a bit of extra glow that shouldn't be there, but otherwise there's little to complain about. It was already good out of the box, and after calibration we managed to refine most of the remaining shortcomings.

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.

The OLED811 handles lower-quality content reasonably well, though it's far from perfect. The "Artifact Reduction" feature helps smooth tonal transitions and on the low setting delivers a pretty good result. It doesn't remove banding between shades as effectively as similar solutions from some competitors, but at least it doesn't introduce new artifacts. That's a sensible setting for everyday viewing. Still, there's some disappointment, because the MediaTek Pentonic 800 chip used here can, in other manufacturers' implementations, deal more effectively with heavy compression even at similarly low settings. A lot therefore depends on how each manufacturer uses its capabilities. We have a few more reservations about the 4K upscaling itself. There is plenty of detail, but the overall image looks fairly soft. Edges are heavily smoothed, which robs the picture of some sharpness and clarity. You can partly correct that with the sharpness slider in the menu, though that will just emphasize outlines rather than recover detail. On the plus side, there is no overscan, so even with an SD signal the TV does not crop the edges of the picture.

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 handling, the OLED811 performs excellently. At 120 Hz, which is useful for console gaming and watching sports, the image stays clear and moving objects don’t leave noticeable trails. The fast response of OLED pixels helps here; you can see it clearly in the UFO test, even on dark backgrounds. There are also motion-smoothing controls. For movies you can adjust the strength of smoothing to your taste, ranging from preserving a cinematic feel to much smoother motion. A separate motion blur reduction control is useful for fast-paced content like live sports broadcasts.

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.

OLED811 has almost everything you could expect from a gaming TV. It supports 120 Hz at Full HD, 1440p and 4K resolutions, and when connected to a PC can reach 165 Hz. It also has VRR, which helps avoid screen tearing with variable frame rates, and ALLM, which automatically switches to game mode. So you don't have to dig into the settings every time you power up your console.

HGiG also works correctly, so once you enable HDR on the console the TV doesn't apply its own brightness adjustments. There's also a Game Bar that lets you check signal parameters and quickly change settings useful while gaming. The list even includes Dolby Vision for games, but there's a significant catch, which you'll read about below.