TCL RM7L vs LG OLED B6

The TCL RM7L is a bright TV. In our measurements its peak brightness hovered around 1600 nits. That's clearly less than the C7L, which can approach 2600 nits, but in real movie scenes the difference between the two models isn't that big. In less demanding shots with many bright elements on screen, the RM7L can hold around 1000 nits, and sometimes a bit more, approaching 1500 nits. It performs worse in dark scenes with small highlights; then their brightness can fall to around 500 nits. However, this behavior is not accidental. The TV intentionally dims small elements to better control the backlight and maintain higher contrast. This comes at the cost of their intensity, but it's typical behavior for local-dimming TVs in a similar price bracket.

Color gamut coverage

In HDR it's not only brightness that matters, but also color. And here the RM7L has a lot to show. Colors are strongly saturated, and a wide color gamut is one of its bigger strengths. In 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 colors look best, while in movies their saturation can be a bit lower than on SQD Mini LED or QD-OLED TVs. The backlight construction itself is also interesting. The RM7L doesn't use the classic red, green and blue diode set. TCL used two green diodes and one blue, and obtains the red color using a PFS phosphor. You can see this in spectrometer measurements, but it doesn't have a major impact on the picture. Colors are still produced correctly.

The LG B6 is a moderately bright OLED. After calibration it reaches about 800 nits, roughly 200 nits more than last year’s B5. That’s thanks to the new budget OLED SE panel from LG Display. In practice it simply gives a bit more headroom and makes HDR in many scenes look fuller than on last year’s lower-tier OLEDs. That doesn’t mean the B6 has no limits. In very bright shots, when a large part of the screen is strongly lit, brightness can drop below 400 nits. This behavior is typical for OLED TVs (especially those from this segment) and that’s when you see the biggest difference versus more expensive models. All things considered, we rate the B6’s results as really solid. It’s still not a TV for breaking brightness records, but the HDR effect is strong enough that you can really feel the step up from ordinary SDR in films.

Color gamut

Using the OLED SE panel has slightly affected wide color gamut coverage. Compared with last year’s model, results fell by a few percentage points. DCI-P3 reaches about 96%, and BT.2020 around 71%. That doesn’t mean the colors on the LG B6 are weak. In most movies and series they look lively, well saturated and simply pleasing to the eye. You only notice a difference in very bright, highly colorful scenes. Then colors lose some intensity compared with QD-OLED panels. This comes from the WOLED panel construction. Besides red, green and blue subpixels it also uses a white subpixel that helps boost brightness. It comes at a cost: at very high luminance some color is effectively “diluted” by the white light, so saturation of some colors can be slightly lower. In everyday use this isn’t a big issue, but you can notice it in the most demanding scenes.

We checked the factory colors 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 present the image as faithfully as possible in line with the creators' intent. On the RM7L this was indeed the best-calibrated mode, although it wasn't without flaws. The biggest issue was the white balance. An excess of red and blue caused the picture to take on slightly pinkish tones. This was visible in both SDR and HDR. Additionally, the luminance response was slightly boosted, which made the image appear a bit brighter but also less contrasty than it should have been.

We tested the LG B6 in Filmmaker Mode, which is the best picture setting available right out of the box. ISF modes deliver very similar results, but in our tests we always stick to Filmmaker Mode for better comparison with other TVs. Each of those modes is, after all, a much better starting point than Vivid or Eco mode, where the picture is heavily boosted and noticeably less natural. With SDR content, the factory settings perform really well. Color errors are small, gamma behaves properly, and the image looks natural during ordinary viewing and does not seem overly "pumped up." It's a bit worse with HDR. When you play that kind of content you can quickly see that the white balance hasn't been set perfectly. Too much blue and red causes the image to shift toward a slightly pink tint. This is also confirmed by measurements of the color gamut and the ColorChecker, where samples clearly drift in that direction. It's not a flaw that completely ruins the picture, but you can notice it in HDR films. So people who care about the most faithful image should consider the calibration we describe later in the review.

Thanks to a fairly extensive calibration menu, we were able to correct the vast majority of the errors described earlier. The biggest change was to the white balance. After calibration it looks very good, so the image lost its pinkish cast and became much more neutral. The luminance response itself also improved. Both the SDR gamma and the HDR EOTF curve are now much closer to the reference values. The image is no longer unnecessarily brightened, and darker areas look more natural and have more depth. Better luminance accuracy also affected the colors, 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 its own way and does not always follow the reference curve exactly. This is most apparent in some darker scenes, where the TV can either slightly lift the shadows or darken them completely. That was the source of the earlier impression of a slightly brightened, less contrasty image. Even so, the calibration delivers a very good result here. It removes the most visible errors and, above all, makes the image much closer to how it should look.

During calibration we focused primarily on HDR content, because that's where the factory settings required the biggest corrections. We didn't neglect SDR mode, though, which after adjustment was brought almost to perfection. Colors are very accurate and brightness is handled as it should be. The biggest improvement in HDR came from correcting the white balance. After removing the excess red and blue, the pinkish tint disappeared and the image became much more natural. Skin tones, whites and all colors that had been shifting toward magenta improved. After calibration most errors fell below a Delta E of 2–3, the threshold at which the average viewer stops noticing differences with the naked eye. The LG B6 can therefore deliver a very accurate image, especially for the manufacturer's entry-level OLED model.

Upscaling and digital image processing are not the RM7L's strong suit. TCL used a MediaTek Pentonic 700 SoC here, designated MT5896, which isn't among the best processors at handling lower-quality content. The biggest problems show up with heavily compressed material from YouTube or regular broadcast TV. The processor can't effectively hide posterization and the characteristic color banding. The feature meant to smooth them does little here, and it often interferes too much with the picture, smoothing faces or fine textures, for example. For that reason, it's best to simply leave it off.

Straightforward upscaling to 4K looks better. Lower-quality sources remain reasonably sharp and retain enough detail. It's not on par with the best processors on the market, but for everyday viewing the result is entirely acceptable.

The LG B6 handles lower-quality sources very well. Much of the credit goes to effective digital image processing, which can mask some source imperfections without overly smoothing the whole scene. The feature "Smooth Gradation" proves particularly useful. It can significantly reduce posterization, which we mentioned earlier, especially in darker areas of the image. The safest choice remains Low or Medium. The function still effectively smooths harsh tonal transitions, but does not yet interfere too much with fine details. The most dedicated purists can, of course, leave it off. Upscaling to 4K also performs very well. Full HD and 720p content retain a good amount of detail, and the image is neither overly sharpened nor excessively blurred. Some limitations become noticeable only with very poor sources below 720p, where the smallest subtitles and fine elements are not always perfectly sharp, but this is true for almost every other TV on the market.

The RM7L uses a 144 Hz VA panel, so right out of the box it's a TV well suited for sports, gaming, and other fast-moving content. The high refresh rate also gives the motion interpolation engine more room to work, allowing it to generate extra frames. On the RM7L it works well, and with the right settings it can noticeably improve motion smoothness without causing an excessive soap opera effect.

One of the biggest advantages of OLED panels is their very fast pixel response time. This keeps the image sharp and prevents the visible smearing that often appears on LCD TVs. However, there is a downside. During slow camera pans, motion can look more choppy than on LCD screens, where the slower panel naturally masks some of that effect. Fortunately, on the LG B6 you can easily soften this with TruMotion. With the motion smoothing properly adjusted, you can achieve smoother motion without giving the picture an excessive soap-opera effect.

You can say almost nothing but good things about the RM7L when it comes to gamer features. The TV supports ALLM, VRR, Dolby Vision Gaming and works correctly with HGiG, so it’s hard to point out any major omissions in that area. In practice this means automatic switching to low-latency mode, a smoother picture 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 also added a few extra options, like a crosshair and brightening of dark parts of the image, which can be useful in some titles. The biggest downside comes from the use of the Pentonic 700 processor. Only two of the four HDMI ports support the full HDMI 2.1 standard. With a single console this won’t matter much, but when connecting two consoles and a PC you may run out of space. Especially since one of those ports may also be needed for eARC and a soundbar.

LG OLED B6 offers a powerful set of advantages for gamers; it's simply a complete platform for PS5, Xbox Series X/S, or a solid PC. It has four full-size HDMI 2.1 ports with 48 Gbps bandwidth, so you can skip the annoying cable swapping when you want to connect several newer devices at once. We get the full suite of sync technologies – from classic VRR to G-Sync and FreeSync. The screen seamlessly matches the refresh rate to the frame output produced by the console or graphics card. Of course ALLM is included: the B6 automatically detects a running game and immediately cuts input lag to a minimum. HDR handling is also excellent. The TV supports Dolby Vision, and a properly implemented HGiG standard means that after an initial calibration in the console settings the picture won’t suffer from blown-out highlights or lost detail in bright areas. The cherry on top is the Game Bar. Instead of digging through the full menu during gameplay, one click lets you adjust shadow visibility, tweak selected settings, or simply check the display’s current operating mode. All of this makes the LG B6 a great choice for gamers.