TCL RM7L vs LG OLED C6 (WOLED)

TCL RM7L is a bright TV. In our measurements its peak brightness hovered around 1600 nits. That is clearly less than the C7L, which can approach 2600 nits, but in real film scenes the difference between the models is not that large. In less demanding shots with many bright elements, the RM7L can sustain about 1000 nits, and sometimes even a little more, getting close to 1500 nits. It performs worse in dark scenes with small points of light, where their brightness can fall to around 500 nits. This is not random behaviour. The TV intentionally dims fine details to better control the backlight and preserve higher contrast. That comes at the expense of their intensity, but it is typical behaviour for TVs with local dimming in a similar price bracket.

Colour gamut coverage

In HDR not only brightness matters but also colour. And here the RM7L has plenty to show. Colours are highly saturated and a wide colour gamut is one of its major strengths. In our DCI-P3 measurements it reached about 96%, and BT.2020 around 83%. It is worth remembering that on a TV with this kind of backlight the result can vary depending on the scene. On test patterns colours look best, while in films their saturation is sometimes a little lower than on SQD Mini LED or QD-OLED TVs. The construction of the backlight itself is also interesting. The RM7L does not use the classic red, green and blue LED set. TCL used two green LEDs and one blue, with the red produced by a PFS phosphor. This shows up in spectrometer measurements, but it does not have a major impact on the picture. Colours are still rendered correctly.

The HDR performance of the LG C6 is really very good. LG Display's new WOLED panel has primarily brought a considerable increase in brightness. In our unit we measured around 1,500 nits and, importantly, the TV can deliver similar values in many typical film scenes. That gives the HDR the necessary impact. Bright highlights, lamps and sunlight can be really intense, and most HDR films simply look very impressive. Of course it's still an OLED, so brightness falls in scenes with a lot of white. This is well illustrated by the fifth scene in the film The Meg, where the C6 reached around 600 to 700 nits. That's still a very good result, but it also shows that the new panel hasn't shed all the limitations typical of OLEDs.

Colours

When it comes to colours, 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 colours are very saturated and, importantly, stable across different scenes. This is worth emphasising, because not every TV behaves the same in this respect. In some RGB Mini LED models colour saturation can depend more strongly on image brightness. A wider colour palette is nowadays offered mainly 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 produce suitably saturated colours in most film scenes.

We checked the out-of-the-box colours in Filmmaker Mode, the best picture setting available to the user. TCL has been using it in its TVs for two years, and its aim is to reproduce the image as faithfully as possible in line with the creators' intent. On the RM7L it was indeed the most accurately set mode, although it was not without flaws. The biggest problem was the white balance. Too much red and blue made the image shift towards slightly pink tones. This was visible in both SDR and HDR. On top of that the brightness response was slightly boosted, making the picture appear a little brighter but at the same time less contrasty than it should be.

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.

Thanks to the fairly extensive calibration menu we were able to correct the vast majority of the previously described issues. The biggest change concerned the white balance. After calibration it now looks very good, so the picture shed its pinkish tint and became much more neutral. The luminance response has also improved. Both the SDR gamma and the HDR EOTF curve are now much closer to the reference values. The picture is no longer unnecessarily brightened, and darker areas look more natural and have greater depth. Better luminance accuracy also affected the colours, which after calibration are noticeably more accurate. Not everything could, however, be set perfectly. With HDR material the RM7L still interprets part of the signal in its own way and does not always follow the reference curve precisely. This is most apparent in some darker scenes, where the TV can either slightly lift the shadows or darken them completely. That is where the earlier impression of a slightly brightened, less contrasty picture came from. Despite this, the calibration delivers a very good result. It removes the most visible errors and, above all, makes the picture much closer to how it should look.

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 colour errors dropped to values below 3, often even around 2. In practice this means very accurate colour reproduction, both in SDR and HDR. An interesting quirk only appeared with the luminance response in HDR. On a standard EOTF chart everything looks almost ideal and at first glance it would be hard to criticise. Only when we measured the TV's behaviour with filters based on actual film scenes did it become clear that the C6 has a slight tendency to artificially boost image brightness.

This is not a huge difference and many people may even view it positively, because HDR consequently looks a little more striking. From the perspective of fidelity to the source material this is not ideal, however, as some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is rather unusual for LG. In previous generations the brand's TVs typically stuck very closely to the reference picture characteristic after calibration. With the C6 we are still very close to the standard, but this subtle brightness boost is indeed noticeable in films and TV series.

Upscaling and digital image processing are not the RM7L's strong suit. TCL has used the MediaTek Pentonic 700 chipset here, designated MT5896, which is not among the best processors when it comes to handling lower-quality source material. The biggest problems appear with heavily compressed content from YouTube or standard broadcast TV. The processor cannot effectively hide posterization and the characteristic banding between tones. The feature intended to smooth these issues does little to help, and can also interfere with the image too much, smoothing, for example, faces or fine textures. For that reason it is best simply not to use it.

Standard upscaling to 4K looks better. Lower-quality content is sufficiently sharp and retains an adequate amount of detail. It is not on a par with the best processors on the market, but for everyday viewing the result is entirely acceptable.

Here the LG C6 has taken a real step forward. 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 considerable plus, because in this area LG's processor this year performs excellently. The "Smooth Gradation" function in particular works very well. With heavily compressed material it can effectively hide ugly banding and artefacts that often appear, for example, in lower-quality streaming. It's best to leave it set to "Low". That way the improvement is clear and the TV does not yet start blurring fine details. Higher settings smooth the image more aggressively but can already remove some of the natural texture of objects on the screen. Upscaling itself also performs very well. Lower-resolution content is sharpened correctly, edges look clean, and the processor quite effectively reconstructs fine details. In this respect the C6 is already very close to LG's best TVs and the differences compared with the G6 are small.

The RM7L features a 144 Hz VA panel, so from the outset it is well suited to sports, gaming and other fast-paced content. The high refresh rate also gives the motion interpolation more scope, allowing it to generate additional frames. On the RM7L it works well and, with the right settings, can noticeably improve motion smoothness without an excessive soap opera effect.

LG C6 received a panel with a maximum refresh rate of 165 Hz, which is great news above all for gamers using a powerful PC. In films, sport or on consoles we will of course make use of up to 120 Hz, but even then it is hard to fault the motion clarity. As befits an OLED, the panel's response time is almost instantaneous. Moving objects therefore do not leave the characteristic smearing or trails that we can still see on LCD televisions. This is especially noticeable in sport and fast-paced games, where the picture remains very clean even during dynamic movement.

For films and television LG has also prepared the TruMotion motion smoothing system. In the user settings you will find two separate sliders. De-Judder primarily addresses low frame-rate content, that is mainly films and TV series at 24 fps. You can use it to slightly reduce the characteristic judder or set a higher value if you want a very smooth image. De-Blur is useful for higher frame-rate material, chiefly sports broadcasts and 50/60 fps television.

The RM7L earns almost nothing but praise when it comes to features for gamers. The TV supports ALLM, VRR and Dolby Vision Gaming and works properly with HGiG, so it’s hard to point to any major omissions in that regard. In practice this means automatic switching to a low-latency mode, smoother motion at variable frame rates and accurate brightness reproduction in HDR games. There’s also a very useful Game Bar. From it you can quickly check frame rate, VRR status, signal format or aspect ratio, and change the key settings without leaving the game. TCL has also added a few extra options, such as a crosshair overlay and brightening of dark image areas, which can be handy in some titles. The biggest drawback stems from the use of the Pentonic 700 processor. Only two of the four HDMI ports support the full HDMI 2.1 standard. That won’t matter much with a single console, but if you connect two consoles and a PC you may run out of ports, especially since one of those ports may be needed for eARC and a soundbar.

LG has long focused heavily on gamers, 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 at up to 165 Hz. There is also VRR from 40 to 165 Hz, ALLM and a properly working HGiG. A big plus is support for Dolby Vision in games, so the Xbox Series X can use that format without giving up Game Mode. It's rounded off by a Game Bar, from which you can quickly check key signal parameters and change settings without leaving the game. In terms of features, the C6 is therefore one of those TVs that is really hard to fault. Whether you're gaming on a PlayStation, an Xbox or a PC, practically everything you could expect from a modern gaming TV is available here.