TCL A400 PRO vs LG OLED C6 (WOLED)

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 HDR effect on the LG C6 is really very good. LG Display's new WOLED panel primarily brought a significant increase in brightness. In our unit we measured around 1,500 nits and, importantly, the TV can show similar values in many normal movie scenes. That gives HDR the proper impact. Bright highlights, lamps, or sunlight can be really strong, and most HDR movies simply look very impressive. Of course it's still an OLED, so brightness drops in scenes with a lot of white. The fifth scene of The Meg illustrates this well, where the C6 reached about 600-700 nits. That's still a very good result, but it also shows the new panel hasn't removed all the limitations typical of OLEDs.

Colors

When it comes to color, there is also little to complain about. The C6 covers about 99% of the DCI-P3 gamut and roughly 75% of BT.2020. In practice the colors are very saturated and, importantly, stable regardless of the scene. That's worth emphasizing, because not every TV behaves the same in this respect. In some RGB Mini LED models color saturation can depend more strongly on image brightness. Today a wider color gamut is mainly offered by QD-OLED TVs and new SQD models with a new generation of quantum dots. However, the C6 still performs very strongly here and is able to generate appropriately saturated colors in most movie 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.

Right out of the box the LG C6 is pretty well set up, especially if you choose Filmmaker mode. In SDR material the white balance is decent, although as brightness increases it starts to lack a bit of red. The picture becomes a little cooler as a result, but it’s not such a big difference that it stands out during normal viewing. More happens in the brightness response itself. Gamma is a bit low and instead of holding at 2.4 it sits closer to 2.1–2.2 over much of the range. In practice the C6 slightly brightens midtones. Shadows are therefore more readable, but the image loses some depth compared with how it should look in a dark room. In HDR the situation is a bit more interesting. The start of the grayscale looks very good, but from about 20–30% brightness the white balance starts to drift more and more. As brightness rises there’s more red and a noticeable lack of blue. In the brightest highlights the difference is already significant and also affects reproduction of some colors. The EOTF curve itself is handled fairly well over most of the range. The C6 only has a tendency to slightly brighten the image, which we also saw during our film comparisons. The largest deviation appears around the brightest highlights, where the TV begins to adapt the signal to the panel’s capabilities. So the out-of-the-box Filmmaker mode in HDR isn’t perfect, but overall it performs well. The biggest room for improvement is the white balance, especially at high brightness.

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.

LG TVs have been very receptive to calibration for years, and the C6 is no exception. After adjustment the white balance was set almost perfectly, and most color errors dropped to values below 3, often even around 2. In practice this means very accurate color reproduction in both SDR and HDR. An interesting detail appeared only with the HDR brightness characteristic. On a classic EOTF chart everything looks nearly ideal, and at first glance it would be hard to find fault. Only when we measured the TV’s behavior using filters based on actual movie scenes did it become clear that the C6 has a slight tendency to artificially boost image brightness.

It’s not a huge difference and many people may even see it as a positive, because HDR looks a bit more impressive this way. From the standpoint of fidelity to the source material this isn’t ideal — some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is somewhat unusual for LG. In previous generations, the brand’s TVs typically stuck very closely to the reference tone curve after calibration. With the C6 we’re still very close to the standard, but that subtle boost in brightness is indeed noticeable in films and series.

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 LG C6 has taken a really big step forward here. The TV uses the same processor found in the flagship G6, and in terms of image processing the two models are very similar. That’s a big plus, because in this area LG’s processor this year performs excellently. The "Smooth Gradation" feature works especially well. With heavily compressed material it can effectively hide ugly tonal transitions and artifacts that often appear, for example, in lower-quality streaming. It’s best to leave it set to "Low." Then the improvement is clear, and the TV doesn’t yet start blurring fine details. Higher levels smooth the image more, but can already remove some of the natural texture of objects on the screen. The upscaling itself also performs very well. Lower-resolution content is sharpened properly, edges look clean, and the processor quite effectively rebuilds fine details. In this regard the C6 is already very close to LG’s best TVs, and the differences compared with the G6 are small.

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.

The LG C6 features a panel with a maximum refresh rate of 165 Hz, which is great news especially for gamers using a powerful PC. For movies, sports, or consoles we'll of course use up to 120 Hz, but even then it's hard to fault the motion clarity. As you'd expect from an OLED, the panel's response time is almost instantaneous. Moving objects therefore don't leave the characteristic smears you still see on LCD TVs. This is particularly noticeable in sports and fast-paced games, where the picture remains very clean even during dynamic motion.

For movies and TV, LG also provides the TruMotion motion-smoothing system. In the user settings you'll find two separate sliders. De-Judder is mainly for low-frame-rate content, that is primarily 24 fps films and series. It can slightly reduce the characteristic judder, or be set higher if you want a much smoother image. De-Blur is useful for higher-frame-rate material, mainly sports broadcasts and 50/60 fps television.

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.

LG has focused heavily on gamers for years, and the C6 really lacks nothing important. The TV supports 4K at 120 Hz from consoles, and when connected to a PC it can run up to 165 Hz. It also offers VRR from 40 to 165 Hz, ALLM, and properly working HGiG. A big plus is Dolby Vision support for games, so the Xbox Series X can use that format without sacrificing game mode. The package is rounded out by a Game Bar that lets you quickly check key signal parameters and change settings without leaving the game. In terms of features, the C6 is one of those TVs that’s really hard to find fault with. Whether you play on PlayStation, Xbox, or PC, practically everything you could expect from a modern gaming TV is available here.