LG 55 B4 vs LG OLED C6 (WOLED)

The HDR brightness performance of the LG B4 is impressive, even though it doesn't surpass 1000 nits. Its luminance stability is consistently strong across various scenarios, delivering a reliable viewing experience. The only instance where the TV shows slight weakness is in scenes with large areas of bright white, which has long been a challenge for OLED technology. However, perfect contrast, deep blacks, and excellent brightness ensure a fully immersive HDR experience. Furthermore, the TV’s remarkable 99% coverage of the DCI-P3 colour gamut enhances its colour vibrancy, making images appear rich and visually striking. This level of colour accuracy and brightness balance firmly places the LG B4 among the top choices for HDR content.

The HDR effect on the LG C6 is really very good. LG Display's new WOLED panel primarily brought a significant increase in brightness. In our unit we measured around 1,500 nits and, importantly, the TV can show similar values in many normal movie scenes. That gives HDR the proper impact. Bright highlights, lamps, or sunlight can be really strong, and most HDR movies simply look very impressive. Of course it's still an OLED, so brightness drops in scenes with a lot of white. The fifth scene of The Meg illustrates this well, where the C6 reached about 600-700 nits. That's still a very good result, but it also shows the new panel hasn't removed all the limitations typical of OLEDs.

Colors

When it comes to color, 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 colors are very saturated and, importantly, stable regardless of the scene. That's worth emphasizing, because not every TV behaves the same in this respect. In some RGB Mini LED models color saturation can depend more strongly on image brightness. Today a wider color gamut 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 generate appropriately saturated colors in most movie scenes.

The best factory preset offered by LG B4 is the "Filmmaker" mode, which we used throughout our testing. Straight out of the box, the TV delivered fairly accurate colour reproduction. However, the most significant issue in both SDR and HDR content was the white balance. In SDR, there was a noticeable red dominance, giving the image a distinct yellow tint, particularly evident in skin tones and whites. In HDR, this red hue persisted, but the lack of blue also introduced a greenish tint in certain scenes. Additionally, we observed some inconsistencies in grayscale and colour accuracy. Despite these shortcomings, the overall picture quality was still solid for most viewing scenarios.

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.

LG B4 has long been known for offering advanced calibration tools, and it remains one of the few manufacturers that allows such in-depth image adjustments. Thanks to these tools, we calibrated the device to an exceptional standard. The result was incredibly low deltaE errors, considered at a reference level. Both SDR and HDR content now display exactly as the filmmaker intended. This level of precision is one of the reasons LG TVs are frequently used as preview monitors in graphic design and post-production studios.

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 color errors dropped to values below 3, often even around 2. In practice this means very accurate color reproduction in both SDR and HDR. An interesting detail appeared only with the HDR brightness characteristic. On a classic EOTF chart everything looks nearly ideal, and at first glance it would be hard to find fault. Only when we measured the TV’s behavior using filters based on actual movie 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 people may even see it as a positive, because HDR looks a bit more impressive this way. From the standpoint of fidelity to the source material this isn’t ideal — some scenes are simply a touch brighter than the filmmaker intended. Interestingly, this is somewhat unusual for LG. In previous generations, the brand’s TVs typically stuck very closely to the reference tone curve after calibration. With the C6 we’re still very close to the standard, but that subtle boost in brightness is indeed noticeable in films and series.

In this section, we will revisit the smooth transition function while also examining how the TV handles lower-quality content. As we’ve found, the setting responsible for smooth gradation is generally effective, though it does have its drawbacks. While the function works well in SDR content, it becomes less useful in HDR content. Even at the lowest setting, it can blur important details, so we advise against using it in such cases.

The image scaling on the LG B4 is assessed moderately positively. While there is no noticeable edge doubling, the image tends to be somewhat "soft." This can be adjusted by tweaking the sharpness slider to improve the clarity.

The LG C6 has taken a really big step forward here. 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 big plus, because in this area LG’s processor this year performs excellently. The "Smooth Gradation" feature works especially well. With heavily compressed material it can effectively hide ugly tonal transitions and artifacts that often appear, for example, in lower-quality streaming. It’s best to leave it set to "Low." Then the improvement is clear, and the TV doesn’t yet start blurring fine details. Higher levels smooth the image more, but can already remove some of the natural texture of objects on the screen. The upscaling itself also performs very well. Lower-resolution content is sharpened properly, edges look clean, and the processor quite effectively rebuilds fine details. In this regard the C6 is already very close to LG’s best TVs, and the differences compared with the G6 are small.

The maximum refresh rate on the LG B4 is 120 Hz, the bare minimum for those requiring high image fluidity. The manufacturer has equipped the TV with a multi-stage motion smoother called "TruMotion." This feature is split into two sliders: one controls the sharpness of moving images (De-Blur) and the other adjusts judder (De-Judder). Both sliders can be set between 0 and 10, with each level affecting the smoothness, so users can easily find their preferred setting.

The LG OLED B4 panel boasts an impressive average response time of 0.1 ms (based on our measurements), delivering an exceptionally clear image that surpasses the capabilities of LCD TVs, which often have response times of several milliseconds. This is particularly noticeable in the "UFO Test" images, where no trailing blur is visible behind moving objects.

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, sports, or consoles we'll of course use up to 120 Hz, but even then it's hard to fault the motion clarity. As you'd expect from an OLED, the panel's response time is almost instantaneous. Moving objects therefore don't leave the characteristic smears you still see on LCD TVs. This is particularly noticeable in sports and fast-paced games, where the picture remains very clean even during dynamic motion.

For movies and TV, LG also provides the TruMotion motion-smoothing system. In the user settings you'll find two separate sliders. De-Judder is mainly for low-frame-rate content, that is primarily 24 fps films and series. It can slightly reduce the characteristic judder, or be set higher if you want a much smoother image. De-Blur is useful for higher-frame-rate material, mainly sports broadcasts and 50/60 fps television.

The LG B4 has four full HDMI 2.1 ports, each providing 48Gbps bandwidth. This ensures smooth activation of all relevant features without issues, making the television highly suitable for gaming. With its low input lag and extensive functionality, including well-implemented HGIG mode and Dolby Vision gaming with low latency, the B4 is a strong contender for gamers who demand high quality.

A standout feature is GameBar, which allows for on-the-fly adjustments without interrupting gameplay, as well as image adaptations for those with visual impairments. Another key point is that when VRR technology is enabled, the television maintains its contrast, thanks to the OLED panel's structure, though slight flickering in grey shades is to be expected.

In conclusion, the LG B4 is an ideal choice for gamers, seamlessly combining high performance with excellent gaming features. Its 120Hz panel and HDMI 2.1 ports make it a standout option for those seeking top-tier gaming experiences.

LG has focused heavily on gamers for years, 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 up to 165 Hz. It also offers VRR from 40 to 165 Hz, ALLM, and properly working HGiG. A big plus is Dolby Vision support for games, so the Xbox Series X can use that format without sacrificing game mode. The package is rounded out by a Game Bar that lets you quickly check key signal parameters and change settings without leaving the game. In terms of features, the C6 is one of those TVs that’s really hard to find fault with. Whether you play on PlayStation, Xbox, or PC, practically everything you could expect from a modern gaming TV is available here.