TCL P7K / P79K vs TCL A400 PRO

When evaluating the HDR effect, we must make it clear and without marketing embellishment: the P7K/P79K is not and was never meant to be a master in this field. The maximum peak brightness that this panel can generate is only around 300 nits. This is a borderline value, a sort of thin red line between what can be considered a barely satisfactory HDR signal and what is really not much different from standard dynamic range (SDR), unfortunately leaning towards the latter. Synthetic tests found brutal confirmation in reality – our measurements taken during movie screenings showed that luminance in key bright parts of the content rarely exceeded the threshold of 200-250 nits. Therefore, this is not a television that would allow content produced in a wide tonal range to truly shine, and we must openly acknowledge that.

Unfortunately, the issue of color reproduction is presented equally restrained. Although the manufacturer positions this model in the "QLED" family, thanks to the use of a PFS LED filter, the results do not match the heightened expectations. The coverage of the wide DCI-P3 color gamut is only 86%. Compared to the market, this is at best an average result, as most devices that employ additional layers to expand the color spectrum easily achieve values at a minimum level of 90-92%.

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.

Every reliable image quality assessment must begin by selecting the most optimal factory mode. In the case of the tested model P7K/P79K, the choice was confidently made for the "Film" mode. It is this mode that presents an image closest to the creators' intentions, avoiding both the exaggerated brightness of dynamic mode and the excessive dimming known from eco settings. And it must be admitted that, for a device in this price range, the factory calibration is surprisingly decent, although it is not free from a few stumbles. The most noticeable flaw turned out to be an imperfectly adjusted white balance. A slight dominance of the blue component gives the image a subtly cool, chilly character, thus deviating from the exemplary neutrality that the director wanted to show us. The television performs much better in reproducing the grayscale in a standard dynamic range – the gamma curve is executed almost perfectly. A minor reservation can only be made for the darkest parts of the image, where a slight deviation from the norm causes a loss of some detail in the shadows. The most serious challenge for TCL's software, however, was the interpretation of the HDR signal, which is illustrated by the EOTF curve. The television follows its own, rather free path here – the darkest details are disproportionately brightened, followed by a noticeable slowdown in brightness increase for midtones. Fortunately, most of these imperfections are software-related issues that can be eliminated. With this thought in mind, we proceeded to the professional calibration process.

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 calibration process turned out to be a home run, especially in the context of standard dynamic range (SDR) content. We successfully managed to eliminate the TV's tendency to emphasize cool tones, restoring the whites to their natural neutrality. Furthermore, precise adjustments allowed us to correct a slight error in the gamma curve, so the darkest areas of the image regained their proper depth, without a trace of unnatural brightening. The effects are measurable and impressive – in the ColorChecker test, the vast majority of color reproduction errors fell below the perceptual threshold, achieving a deltaE value below 2. This is a result that would not shame much more expensive constructions. Unfortunately, in the case of HDR content, we hit a wall in the form of the inherent limitations of the panel itself. And although we managed to bring the colors in line, the software's specifics mean that the TV still adapts brightness in its own way, as evidenced by the persistent, non-standard EOTF curve. In summary, calibration brings tremendous added value, but one must be aware that it cannot overcome certain physical barriers. A slight boost in black levels, resulting from the lack of local dimming, and limited peak brightness mean that HDR content will not always be able to showcase its full potential. This is simply not the main task of this display; its true strength, especially after professional tuning, lies in the viewing of SDR materials.

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 a series of harsh evaluations, fortunately, the time comes for praise, and this is due to the TCL AiPQ image processor for its work in digital processing and content scaling. It should be noted right away that we are not talking about the level known from flagship designs; nevertheless, in the price segment represented by the P7K/P79K, the results achieved are more than solid. The feature that smooths tonal transitions performs particularly well, effectively eliminating posterization, which are the characteristic bands often visible in materials with higher compression, such as from the YouTube service. The algorithm can elegantly remove unwanted gradients, which ultimately looks really good. The television also competently handles upscaling, which is the task of raising low-resolution materials to 4K standard. The output image, although it may seem a bit too sharp out of the box, fortunately, is not a problem. The software allows for easy adjustment of this parameter using a sharpness slider, so the final appearance can be easily tailored to personal preferences.

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 issue of fluidity and sharpness of the image in motion is inextricably linked to the fundamental parameter of the panel, and in the case of the TCL P7K/P79K, we are dealing with a panel that has a native refresh rate of 60 Hz. This specification already defines its capabilities and makes it difficult to unequivocally recommend it to enthusiasts of dynamic sports broadcasts. During rapid camera movements, the image loses sharpness, and the panel itself also shows a slight tendency to blur, which may be noticeable to more sensitive viewers. Fortunately, not everything in this aspect has been left to chance. The manufacturer has implemented a simple motion smoothing system, which is primarily used in film materials recorded at 24 or 30 frames per second. Thanks to a dedicated slider, the user can independently decide on the final character of the motion – from a fully cinematic, slightly juddery image to achieving a very smooth, almost theatrical effect. It is a simple yet effective tool that allows users to tailor the viewing experience to their own preferences.

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.

Although on paper the native 4K@60Hz matrix might suggest that the TCL P7K/P79K is not a TV tailored for gamers, the reality turns out to be surprisingly different. On the contrary, the manufacturer has ensured a rich package of features that make it a very friendly companion for next-generation consoles. Onboard, we find key technologies such as ALLM, which provides automatic switching to low-latency mode, and VRR, or variable refresh rate, which eliminates screen tearing. The list is completed by support for Dolby Vision Gaming and a simple yet functional Game Bar. However, the real and extremely pleasant surprise is something else. It turns out that the TV easily supports high refresh rate signals of 120 Hz, but at lower resolutions – 1080p and 1440p. This is fantastic news for console owners who know full well how rarely games run in native 4K at a full 120 frames per second. The ability to choose between higher resolution and doubled smoothness is therefore an extremely sensible compromise.

In summary, although the P7K/P79K may not be the target screen for the most avid tournament gamers, it offers a package of options for the casual or occasional console user that is hard to find among many competitors at this price point.

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.