Dreame S100 vs TCL A400 PRO

The Dreame S100 is a relatively bright television. In movie mode, the brightness we measured reached about 600 nits. This is a really good result, although not the highest, considering the capabilities of the competition in this price range. In fullscreen scenes, it is evident that the television can generate an image that strikes with brightness. Unfortunately, when more complex scenes appeared on the screen, the local dimming algorithm in this model tried above all to maintain the deepest blacks. However, this came at the expense of HDR effect – and in a drastic way. In such scenes, the brightness of bright elements dropped below 100 nits, which is a truly tragic result, far from any HDR effect. This aspect can be improved, though not without any "buts." It is enough to change the local dimming setting in the television's menu, but then the blacks in such scenes simply turn gray. It’s a pity that Dreame could not refine the local dimming algorithms better, and the S100 is another example that the mere number of local dimming zones does not always translate into better image quality. As a consolation, it is worth adding that the Dreame S100 is advertised as a "QLED" television, although in reality it utilizes a PFS LED filter. As a result, the colors are appropriately saturated, and the color gamut coverage we measured exceeded 94% of the DCI-P3 palette.

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.

We tested the Dreame S100 in "movie" mode and definitely recommend using this setting for watching all kinds of content. Interestingly, in the deeper settings of the TV, we also find a dedicated "Filmmaker" mode, which is available today from almost every manufacturer. However, in the case of the Dreame S100, we do not recommend using it – it blocks all image-related settings and does not allow any configuration in the menu - not even motion smoothing. So how do the factory colors perform on the S100? Not too bad, but also not great. The TV itself was quite heavily tinted with blue components, which is clearly visible in our white balance measurements. This caused the image to be artificially brightened, and the colors had a slight bluish tint. This is confirmed by the Color Checker palette, which showed how color samples leaned towards blue, generating quite significant color errors. The image in HDR mode looked definitely better, where color errors were not as prominently visible, though they still fell far from ideal. Here, the white balance was also too heavily skewed towards the blue color, which caused quite significant errors in color reproduction.

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 Dreame S100 turned out to be a device very susceptible to professional calibration. In its menu, we found a whole array of advanced options that allowed us to effectively correct factory errors. Thanks to advanced white balance correction – both in SDR and HDR content – we completely eliminated excess blue components. The image immediately became much more natural and pleasant to view. After fully tuning the colors, errors in the Color Checker test dropped below Delta E values of 2-3. For the average viewer, this means that any color distortions have become nearly impossible to notice with the naked eye. This is a really nice surprise, as often new brands in the television market have significant problems with proper implementation and functioning of sliders in the calibration menu. Here, everything worked as it should. The only thing we need to criticize is the way the television manages its brightness in HDR. Due to the specific nature of the local dimming algorithms, we observed anomalies in the EOTF curve we measured. In the areas where high highlights should appear, there is a slight uplift of the curve above the reference line. In practice, this results in unnatural brightening of some of the brightest elements in movies or games. Despite this minor flaw, professional calibration brings a huge, very positive change to this model.

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.

The scaling and digital processing in the Dreame S100 is handled by a technology that the manufacturer proudly calls Dreamind™ Pro AI. However, it is essential to clarify that this is not a proprietary processor but merely a marketing name for a chip from MediaTek – specifically, the model MT5889. Unfortunately, we are talking about quite an outdated unit, from the time when MediaTek lagged significantly behind the competition in terms of performance. This, unfortunately, has a direct impact on the image, as this chip is responsible for that as well. The upscaling in the S100 is rather mediocre, and the processor tends to strongly and artificially sharpen edges (fortunately, this can be somewhat tempered with the sharpness slider in the menu). In the options, we also find a "Contour Smoothing" function, which theoretically is supposed to improve tonal transitions. In practice, it brings almost no improvement – setting it to any level rarely eliminates visible color banding but can unnecessarily blur elements of the image that should remain sharp.

A separate problem is the phenomenon of overscan (clipping the edges of the frame), which is almost always visible here. Although there is an option to set the screen to display the full frame in low-resolution materials, it requires activating the aforementioned Filmmaker mode. And as you already know, this mode completely blocks any other adjustments in the image menu. In our test tables, we noted that the television offers the option to disable overscan, as technically such a feature exists in the system – however, in everyday use, with reasonable image settings, you will not be able to take advantage of it.

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.

When it comes to motion fluidity, the Dreame S100 performs really well. It features a panel with a 144 Hz refresh rate, although in reality, the vast majority of users using it in a traditional way will still be limited to 120 Hz (because today's equipment, apart from PCs, only allows for such values). Thanks to the high refresh rate, the image in motion remains really sharp, largely due to the well-functioning MEMC fluidity enhancer. In the menu, we find predefined modes that allow the TV to efficiently add artificial frames, which effectively improves the fluidity of dynamic sports shots, but also helps get rid of image stuttering in film and series materials recorded at 24 frames.

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 Dreame S100 seems almost like the perfect screen for gamers. The TV is equipped with 2 HDMI 2.1 ports with a bandwidth of 40 Gbps, which means that features such as Auto Low Latency Mode (ALLM) and Variable Refresh Rate (VRR) synchronization in the range of 48-144 Hz work seamlessly on consoles. It also has a well-designed game panel (Game Bar) that allows you to continuously check the most important parameters – from active picture modes to the number of frames rendered by the console, and even the ability to add a crosshair in the center of the screen. All of this looks great on paper, but the biggest issue with the S100 is the implementation of HDR mode in games. The TV does not have a properly implemented HGiG format. As a result, an unsuspecting user may incorrectly configure the console during the initial setup of the display. A wrong configuration can lead to a picture that is too dark or too bright (as a guideline: we suggest setting the brightness in the Xbox console menu to about 600 nits, and in the PS5 to 12 clicks). The Dolby Vision format is also problematic; it often just would not activate at all when using the XBOX – Dreame S100 line. And when it was managed to be activated, gaming was impossible due to a very high input lag that often exceeded 100ms. If the manufacturer can improve the HDR issue in games through an update, the S100 will be truly excellent equipment for gamers. For now, however, one must reckon with compromises.

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.