TCL RM7L vs LG OLED C6 (WOLED)

TCL RM7L is a bright TV. In our measurements its peak brightness hovered around 1600 nits. That’s noticeably less than the C7L, which can get close to 2600 nits, but in real-world film scenes the difference between the models isn’t that large. In less demanding shots, where plenty of bright elements appear on screen, the RM7L can sustain around 1000 nits, and sometimes even a bit more, approaching 1500 nits. It performs worse in dark scenes with small points of light; then their brightness can fall to about 500 nits. This behaviour isn’t random. The TV deliberately dims small elements to better control the backlight and preserve higher contrast. This comes at the expense of their intensity, but it’s typical for TVs with local dimming in a similar price range.

Colour gamut coverage

In HDR brightness isn’t the only thing that matters, colour does too. Here the RM7L has a lot to show. Colours are strongly saturated and the wide colour gamut is one of its main strengths. In our measurements it reached about 96% of DCI-P3 and around 83% of BT.2020. It’s worth remembering, though, 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 can be a little lower than on SQD Mini LED or QD-OLED TVs. The backlight design itself is interesting. The RM7L doesn’t use the classic red, green and blue LED set. TCL used two green LEDs and one blue, with red produced via a PFS phosphor. You can see this in spectrometer measurements, but it doesn’t 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 mainly brought a significant increase in brightness. In our unit we measured around 1500 nits and, importantly, the TV can show similar values in many normal movie scenes as well. That gives HDR real punch. Bright highlights, lamps and sunlight can be genuinely intense, and most HDR movies simply look very impressive. Of course it’s still an OLED, so brightness falls in scenes with a lot of white. The fifth scene from the movie The Meg illustrates this well, where the C6 reached around 600 to 700 nits. That’s still a very good result, but it also shows the new panel hasn’t shed all the limitations typical of OLEDs.

Colours

When it comes to colours, it’s also hard to raise major objections. The C6 covers about 99% of the DCI-P3 gamut and roughly 75% of BT.2020. In practice colours are very saturated and, importantly, stable regardless of the scene. That’s 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 gamut today 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 produce suitably saturated colours in most movie scenes.

Factory colours were checked in Filmmaker Mode, the best picture setting available to the user. TCL has been using it in its TVs for two years, and its purpose is to reproduce the image as faithfully as possible to the filmmakers' intent. On the RM7L it was indeed the best calibrated mode, though not without faults. The biggest issue was the white balance. An excess of red and blue made the image shift slightly toward pink tones. This was visible in both SDR and HDR. In addition, the brightness response was slightly boosted, so the picture looked a little brighter but at the same time less contrasty than it should.

Right out of the box the LG C6 is quite well set up, especially if you choose the Filmmaker mode. In SDR material the white balance is decent, although as brightness increases there is a slight lack of red. The image becomes a bit cooler, but not enough for it to be very noticeable during normal viewing. More is happening in the brightness characteristic. Gamma is a little low and instead of holding at 2.4, for a large part of the range it sits closer to 2.1–2.2. 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 darkened room.

In HDR the situation is a bit more interesting. The start of the greyscale looks very good, but from about 20–30% brightness the white balance starts to drift increasingly. As brightness rises there is more red and a noticeable lack of blue. In the brightest sections the difference is already significant and also affects the reproduction of some colours. The EOTF curve itself is followed quite well through most of the range. The C6 only tends to slightly brighten the image, which we also saw in our film comparisons. The largest deviation appears around the brightest parts, where the TV starts adapting the signal to the panel's capabilities.

The factory Filmmaker setting in HDR is therefore not perfect, but overall performs well. The biggest area for improvement is the white balance, especially at high brightness.

Thanks to a fairly extensive calibration menu we managed to correct the vast majority of the issues described earlier. The biggest change was the white balance. After calibration it looks very good, so the image has lost its pinkish tint and become 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 bright, and darker parts look more natural and have greater depth. Better luminance accuracy has also affected the colours, which after calibration are noticeably more accurate. Not everything could be set perfectly though. In HDR material the RM7L still interprets part of the signal in its own way and doesn’t always stick exactly to the reference curve. You can see this mainly in some darker scenes, where the TV can either slightly lift the shadows or darken them completely. That’s where the earlier impression of a slightly brightened, less contrasty image came from. Even so, the calibration delivers a very good result here. It removes the most visible errors and, above all, makes the picture much closer to how it should look.

LG TVs have long responded very well to calibration, and the C6 is no exception. After adjustments we managed to set the white balance practically perfectly, and most colour errors fell below 3, often down to around 2. In practice this means very accurate colour reproduction in both SDR and HDR. An interesting detail only appeared with the HDR brightness response. On a classic EOTF chart everything looks almost perfect and at first glance it would be hard to find fault. Only when we measured the TV’s behaviour using filters based on real film 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 viewers may even see it as a positive, because HDR looks a bit more striking as a result. From the point of view of fidelity to the source material, however, it’s not ideal — 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 held very closely to the reference picture curve after calibration. The C6 is still very close to the standard, but that subtle brightness 'boost' can indeed be noticed in films and TV series.

Upscaling and digital image processing are not the RM7L’s strong points. TCL has used a MediaTek Pentonic 700 chipset here, labelled MT5896, which isn’t among the best processors at handling lower-quality sources. The biggest issues appear with heavily compressed content from YouTube or regular broadcast TV. The processor can’t effectively hide posterisation and the characteristic banding between shades. The feature meant to smooth these issues does little to help and can also interfere with the picture too much, smoothing faces and fine textures, for example. For that reason it’s best not to use it.

Plain upscaling to 4K looks better. Lower-quality sources are reasonably sharp and retain a sufficient amount of detail. It’s not on a par with the best processors on the market, but for everyday viewing the result is perfectly acceptable.

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

The RM7L uses a 144 Hz VA panel, so right from the start it's well prepared for sports, games and other dynamic content. The high refresh rate also gives the motion interpolation more room to work, so it can generate additional frames. On the RM7L it performs well and, when set correctly, can noticeably improve motion smoothness without producing an excessive soap opera effect.

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, sport and consoles we’ll of course be limited to 120 Hz at most, but even then it’s hard to fault the motion clarity. As you’d expect from an OLED, the panel’s response time is near-instant. Moving objects therefore don’t leave the characteristic smearing you still see on LCD TVs. This is especially noticeable in sport and fast-paced games, where the picture remains very clean even during dynamic movement.

For movies and TV, LG has also included a motion smoothing system called TruMotion. In the user settings you’ll find two separate sliders. De-Judder is primarily for low-frame-rate material, namely movies and TV series at 24 fps. You can use it to slightly reduce the characteristic judder or increase it if you prefer a much smoother picture. De-Blur, on the other hand, is useful for higher-frame-rate content, mainly sports broadcasts and 50/60 fps TV.

When it comes to gamer-focused features, there's almost nothing but praise for the RM7L. The TV supports ALLM, VRR, Dolby Vision Gaming and works correctly with HGiG, so it's hard to point to any major gaps in that area. In practice that means automatic switching to a low-latency mode, smoother motion with variable frame rates and accurate brightness reproduction in HDR games. There's also a handy Game Bar. From it you can quickly check the frame rate, VRR status, signal format and aspect ratio, and change key settings without leaving the game. TCL has added a few extra options too, such as an on-screen reticle and brightening of dark areas, which can be useful in some titles. The biggest downside comes from using the Pentonic 700 processor. Only two of the four HDMI ports support the full HDMI 2.1 standard. With a single console that won't be a big issue, but if you hook up two consoles and a PC you might run out of ports, especially since one of those ports may also be needed for eARC and a soundbar.

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