TCL A400 PRO vs TCL X11L

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 produce a noticeably more attractive picture than in SDR. However, it is not a level that overwhelms with sheer brightness. The A400 Pro therefore isn’t one of those TVs that ‘attack’ the viewer with a powerful flash in every eye-catching scene. The biggest limitation is seen with small bright elements on a dark background. Because of fairly aggressive local dimming control, the TV can significantly reduce their brightness, in extreme cases even to around 100 nits. This means that small lights, sparks, stars or individual highlights can be much less visible than they should be. It’s worth adding, however, that this isn’t without reason. The A400 Pro does this to maintain as deep a black level as possible and to limit the halo effect around bright objects. So it’s an intentional compromise: the TV more often opts for deeper blacks rather than maximally bright, point-like highlights. On one hand this can be understood, especially given the 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, allows for suitably saturated colours. Coverage of the DCI-P3 gamut measured around 94%, and BT.2020 around 74%, which is a solid result for this class.

Such a large number of zones did not only result in deep, inky blacks, but also in screen brightness. The X11L is an extremely bright television. Peak brightness can easily exceed 4,000 nits, and with the special "Boost" mode active it can, in specific conditions, even reach marketing figures around 9,000 to 10,000 nits. It is undoubtedly one of the brightest, if not the brightest, screens on the market. So how do these numbers relate to real film measurements? The results are very good, though of course far from the marketing claims. The brightness we measured in real film scenes was around 2,000 to 3,000 nits. That is an excellent result, given that the vast majority of content available is recorded and produced for those brightness levels, even the rare material mastered to 4,000 nits. But it also clearly shows that the figures the manufacturer touts do not always translate directly to the video material you have at home. The only "quirk" (if you can call it that) is that when very small, bright elements appear on screen, their brightness falls below 2,000 nits. The dimming algorithm does this deliberately to preserve deep blacks and minimise halo. This is entirely understandable, and the effect is still very impressive, but it also shows that even with such powerful hardware, Mini-LED technology has its limits and does not always work without compromise. In HDR itself, brightness is not the only thing that matters; colour saturation and the colours themselves do too. On the X11L these are very good thanks to the new Super QLED (SQD) quantum dots. The application of a new coating filter has delivered excellent results in covering the P3 colour gamut and the ultra-wide BT.2020. Although it does not reach the promised 100% of BT.2020, figures around 89 to 90% can be considered excellent. Colours are not far off those of RGB Mini-LED screens. We can even say they are more stable, due to a less demanding algorithm that RGB screens often struggle with.

As standard, we performed colour measurements in the best‑tuned Filmmaker Mode, the mode that is designed to be closest to the creators' intentions. The A400 Pro of course also offers other picture modes, but in practice these come with considerably larger colour errors and interfere more with the character of the image. Therefore we will not deal with them in detail in this part of the test. So how does the out‑of‑the‑box colour reproduction fare? In short: really very good. Actually, looking at our measurement results, downright excellent. Both the white balance and the luminance response were set surprisingly precisely. The errors were so small that during measurements we genuinely rubbed our eyes in amazement. Such good factory settings do not happen often, even in TVs operating in Filmmaker Mode. All the more credit is due to TCL, because the A400 Pro right out of the box can deliver an image very close to how the source material should look. The results were so good that one could easily think someone had already given this unit extra attention and tried to calibrate it.

Our nitpicking really comes down to just one thing. In SDR content the image was slightly brighter than the dark‑room reference intends, because the factory gamma was set closer to 2.3 than to 2.4. This is not a large error and most viewers will probably not even notice it.

It should, however, be noted that we are talking about our specific test sample. With factory colours there can always be some variation between units, production batches or screen sizes. We do not assume, therefore, that every A400 Pro will look identical straight out of the box.

Turning on what should theoretically be the best Filmmaker Mode, you expect a one-to-one image of what the director saw. On the X11L it's fairly good, but this mode has obvious faults, which our measurements immediately exposed. Let's start with SDR. Both the white balance and the gamma are simply misaligned. The whites contain too much blue and red, giving the screen a slight pink tint. That also affected the gamma, which instead of holding the cinematic 2.4 drifts closer to 2.2. What did that result in? The whole image is therefore more pushed and looks artificially brighter. The worst comes at the end, namely the HDR measurements. Apart from this slight white-balance shift, the X11L fails on the brightness-management curve, the so-called EOTF. What we saw in the measurements immediately explains what we noticed earlier in films. The image is unnaturally brightened because the curve is massively overshot above the reference. The TV simply blatantly lifts the dark parts of the picture to create a "wow" effect, completely ignoring the director's intent.

Despite its superb factory calibration, we couldn't resist checking how the TCL A400 Pro would respond to professional calibration. Since the starting point was so good, we were all the more curious whether there was anything more to be had from the TV. And here we must boast: we managed to reduce our unit's colour errors to absurdly low levels. Measurements below a value of 1 are not something you see every day, even in very good TVs. Such results are more commonly 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 therefore simply performed exceptionally well after calibration. The only gripe we have after closer analysis relates to the luminance behaviour. The TV adjusts luminance depending on the content being displayed and quite often the picture is slightly darker than the reference calls for. This is most likely due to the way the Mini-LED backlight and local dimming algorithms operate in this model. However, this does not spoil the overall impression, because in terms of colour accuracy alone the calibrated A400 Pro showed a level that was really hard to expect.

After professional calibration we primarily managed to fully tame the SDR signal. Here the X11L responded perfectly to our adjustments. We were able to completely correct the white balance, remove that pink tint and set gamma to a stable 2.4. After that the picture finally became consistent with the director's vision, natural and free of artificial boosts. We also made minimal tweaks to HDR, but the TV's biggest flaw remained unchanged. It's of course about how the X11L manages its brightness and how much it overshoots the EOTF curve. Unfortunately, TCL provides virtually no tools to adjust this parameter. Even during professional calibration the software offers no way to rein in this curve, so the TV will always tend to brighten the image in HDR on its own.

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 is hard to call it anything clearly above average. The upscaling itself is adequate: edges are smoothed fairly well, the picture does not look overly sharp or "pixelated", and lower-quality content can be watched without much discomfort. At the same time, the overall image is slightly soft and lacks the precision offered by the best image processors in more expensive TVs.

Much worse, however, is how it handles tonal transitions caused by strong signal compression. TCL has equipped the A400 Pro with a "Gradual Smoothing" feature that, in theory, should limit visible colour banding and artifacts in lower-quality material. In practice, though, 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 is best to leave this feature off. The A400 Pro copes decently with basic image scaling, but if you often watch heavily compressed content with noticeable posterisation, this model will not be among the best choices.

Much like the C8L model we tested earlier, TCL has delivered a substantial upgrade in its flagship X series. It's all thanks to the MediaTek Pentonic 800 processor used in this model. Thanks to it, features for smoothing tonal transitions and even upscaling content to higher resolutions finally look as they should. The biggest Achilles' heel of previous TCL models has at last been addressed. The processor handles digital processing superbly and, in this respect, the TV no longer lags behind flagship models from Korea or even the most refined ones from Japan.

The TCL A400 Pro is equipped with a 144 Hz panel, but in practice we are most interested in its behaviour at 120 Hz. That is the frequency most consoles are limited to today, as well as many sports broadcasts and high-frame-rate content. At that rate the TV performs quite well. The sharpness of moving objects is really good, especially after properly configuring the motion smoothing. The "Motion Clarity" function is responsible for improving smoothness. Its settings include two sliders that let you tailor how the motion smoothing operates to your preferences, separately for lower and higher frame-rate material. This makes it possible to achieve both a more cinematic look and a noticeably smoother picture. Those who do not want to fiddle with manual configuration can use presets such as low, medium, high, cinema or nature.

From a specification standpoint the X11L can impress, supporting refresh rates up to 144 Hz at 4K, and it can be pushed to as much as 288 Hz in Full HD. However, from a real-world usage perspective we were most interested in how the screen performs at 120 Hz. After all, that is the limit for today’s hardware, with current-generation consoles leading the way. How does that look in practice? Even though it uses a VA panel, the screen does not exhibit significant smearing. With very fast-moving objects you can notice a slight trailing, but it is subtle enough that it hardly stands out while gaming or watching sport. The motion smoothing feature called "Motion Clarity" is also very useful here, allowing you to adjust motion smoothness to your preference. Recommended settings can be found in the picture.

In terms of features for gamers the TCL A400 Pro performs brilliantly. The TV has practically everything you can 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-generation consoles and a PC. Another plus is the presence of the Game Bar, a special 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 also adjust the appearance and behaviour of some settings to suit your preferences. This solution 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 connectors out of the four available, and one of them also serves as eARC. In practice this means that if someone wants to connect two next-generation consoles and a soundbar, they may run into some limitations. In that scenario you will have to either swap devices or use additional equipment, such as an AV receiver or a soundbar with HDMI inputs. Even so, it is hard not to rate the A400 Pro very highly as a TV for gamers. The gaming feature set here is truly powerful.

For gamers the X11L is simply a superb screen. TCL has already accustomed us to the fact that it packs virtually every available feature into its products, and the flagship from the X series is no different. Thanks to the new processor, the X11L has as many as four HDMI 2.1 ports with full 48 Gbps bandwidth. Naturally, HDMI 2.1 brings a set of very useful features, such as Auto Low Latency Mode (ALLM) and VRR frame synchronisation, covering the full refresh range up to 288 Hz. All these features can be conveniently controlled from the dedicated Game Bar. Interestingly, its appearance can be customised to your taste; there are three preset themes to choose from, directly referencing the Nintendo, PlayStation and Xbox consoles. And speaking of Xbox, the X11L also supports Dolby Vision Gaming without any issues.

When gaming in the standard HDR10 format, however, you need to bear in mind the specific tuning of the brightness curve, which can prove troublesome during initial setup. Although the TV supports HGiG, configuring everything via the PlayStation or Xbox system menu can be difficult. The screen’s algorithms tend to artificially brighten the test checkerboard pattern, making it really hard to hit the correct white clipping point by eye. For HDR10 to look correct, we suggest manually setting the console brightness in the console menu to around 2,500–3,000 nits.