The focal point of this review is the LG OLED55C7P, which is a member of the C7 series. The OLED55C7P is one of the three LG OLED TVs in the 55-inch class this year. Even though it omits the Picture-on-glass design and the integrated sound bar that can found on the higher end model from the E7 series, the picture quality is identical since they use the same OLED panel.
The OLED55C7P has a flat screen and an inclined stand. The protruding section on the back panel, where inputs and electronics reside, is white. In comparison, this section was gray on its predecessor. Furthermore, the OLED55C6P had a curved screen and a curved stand, which was black at the base, but the pedestal was transparent. The OLED55C7P’s stand doesn’t have a pedestal, so there is slightly less clearance beneath the display in comparison to the OLED55C6P.
Unlike the OLED55C6P, the OLED55C7P doesn’t support the passive 3D format, so you won’t be able to watch any 3D content on it. There is a difference in the number of HDMI inputs on the OLED55C7P vs OLED55C6P. The former has 4 HDMI, whereas the latter had 3 HDMI inputs. Additionally, 3 of the OLED55C7P’s HDMI inputs are side-facing and 1 is downward-facing. On the other hand, all 3 of the OLED55C6P’s HDMI inputs were side-facing, and so were its 3 USB ports, one of which was USB 3.0 In case of the OLED55C7P, only 1 of the USB ports (the USB 3.0 port, to be precise) is side-facing. The remaining two USB ports (USB 2.0) are rear-facing. The optical digital audio output, the Ethernet port, the antenna/cable input, the shared component/composite input are rear-facing on the OLED55C7P, and downward-facing on the OLED55C6P.
Considering most SDR content has low-to-mid average picture level, the picture quality in this case is mostly identical on the OLED55C7P and OED55C6P. However, the former has an advantage in scenes with mid-to-high average picture level, which are typical of some winter sports such as hockey or skiing, due to the brightness being up to 25% higher on the OLED55C7P vs OLED55C6P. The gamma used with the BT.709 standard is a relative luminance function, meaning the extra brightness on the new model makes the entire picture brighter, provided you run your TV at maximum settings. Therefore, the OLED55C7P is more suitable for high-ambient light environments, but if you calibrate your TV to 100cd/m2 or less for a dark room, the difference between the two models is diminished. This only applies to SDR content, though.
When it comes to HDR content, the OLED55C7P’s advantage over the OELD55C6P doesn’t subside based on how your calibrate the TV. The reason is that the ST.2084 Perceptual Quantizer, which HDR10 and Dolby Vision use, is an absolute luminance function, so the digital code words are mapped to the same luminance values on different displays. Approximately half of the said code words are in the 0-100cd/m2 range, where the two TVs perform identically. In addition to shadows and mid-tones, most of the diffuse white range is also similarly reproduced by the OLED55C7P and OLED55C6P. However, small specular highlights (5% window size) can be rendered up to 25% brighter on the OLED55C7P vs OLED55C6P.
There are different picture presets you can use when watching HDR content. In case of the OLED55C7P, the Dolby Vision and HDR10 modes are named identically, whereas the OLED55C6P used distinct names for the presets of the two HDR formats. The OLED55C7P’s picture modes that track the D65 white point more closely (e.g. HDR Standard, Cinema) have more neutral color temperature, but a lower peak brightness than the ones that are closer to D93 white point (e.g. HDR Vivid, Cinema Home). Using one of the latter would lead to a colder color temperature, and a bluish tint. The same applies to the OLEDC6P, except that it had a preset called HDR Bright, but lacked Cinema and Cinema Home (with HDR10 content).
Owing to the slight increase in the DCI-P3 color space coverage, the OLED55C7P is able to show somewhat more saturated colors than OLED55C6P. That being said, the approximately 99% DCI-P3 coverage refers to the OELD55C7P ability to render colors in HDR content only at a single luminosity level. Color volume, on the other hand, allows for determining color saturation not only in mid-tones, but also in shadows and highlights, since it looks at the DCI-P3 coverage at different luminosity levels. The difference between the two models is most obvious in highlights, followed by mid-tones. In other words, there is a more sizeable increase in the DCI-P3 coverage for specular highlights than for mid-tones and shadows. Since they both use 10-bit panels, the OLED55C7P and OLED55C6P are capable of displaying over a billion color shades, hence color gradation is smooth.
The OLED55C7P is able to generate and apply dynamic metadata to HDR10 content, which natively contains only static metadata. Unlike the OLED55C6P, which didn’t have Active HDR processing, the OLED55C7P is able to avoid compression of the dynamic range during scenes without highlights. This is important because HDR10 content, without any additional processing, is only optimized for highlights, whereas all the remaining scenes are compressed based on the maximum content light level (maxCLL) defined by static metadata. This leads to some mid-tones being rendered darker when there is no reason for that (i.e. the scene doesn’t have highlights). However, it needs to be said that this is less of a problem with content mastered to 1,000cd/m2 than it’s with HDR10 mastered to 4,000cd/m2. Therefore, the latter benefits most from the Active HDR processing on the OLED55C7P.
Dolby Vision is another HDR format that both models support. Unlike HDR10, Dolby Vision has dynamic metadata, and natively is capable of scene-by-scene optimization. The OLED5C7P also supports HLG (Hybrid Log Gamma), which is a standard intended mainly for HDR TV broadcast. Furthermore, the new model is ready support Advanced HDR by technicolor at some point in the future via a firmware update.
There is no difference in the total audio power output on the OLED55C7P vs OLED55C6P since they both have 40 Watts of amplification. That being said, the former allocates 20 Watts to its sub-woofers, and the speaker configuration is 2.2 channel. On the other hand, the OLED55C6P didn’t have sub-woofers, so it had a 4.0 channel speakers instead. Therefore, the bass is deeper on the OLED55C7P. Furthermore, this model has a Dolby Atmos decoder, which the OLED65C6P lacked, meaning that the OLED55C7P allows you to either listen Dolby Atmos soundtracks directly through the TV speakers, or pass-through the bitstream to a compatible receiver via HDMI Audio Return Channel.