LG CX OLED TV Review

The CX OLED is in LG's high-end OLED lineup. It's a direct replacement to the LG C9 OLED and sits between the LG BX OLED and LG GX OLED. Since there aren't many OLED TVs on the market, its main competitors are other LG TVs, the Sony A8H, and the Sony A9S. Its LED competitors are the Samsung Q90T and the Vizio P Series Quantum X 2020.

The CX has a sleek design with a premium feel to it, and it looks very similar to the LG C9 OLED. The silver metal on the back is a bit darker than its predecessor, but it has the same stand that allows the TV to sit close to the table.

The stand is very solid and the TV doesn't wobble all that much. It's almost as wide as the TV, so you need a big table to place it on. Also, since the TV sits so low to the table, placing a soundbar in front of it could potentially obstruct the screen.

Footprint of the 55" TV stand: 36" x 9.6".

The back is identical to the LG C9 OLED and LG C8 OLED. The top part that holds the panel is solid metal, and the bottom part that holds the inputs is textured plastic with horizontal lines on it. There are both side-facing and back-facing inputs, and there's a plastic cover on the stand for cable management.

The borders are thin and aren't distracting.

The top half of the CX is very thin, but it gets thicker at the bottom where the inputs are housed. It shouldn't stick out much if you wall-mount it.

Outstanding build quality, like the LG C9 OLED. The front of the stand and the top half of the back are made out of metal, but there's a bit of flex on the top half of the TV. The back of the stand and the panel holding the inputs are made out of solid plastic that feels like metal.

Like all OLED TVs, the CX has an infinite contrast ratio since it's able to turn off individual pixels, resulting in perfect blacks.

Since this TV doesn't have a backlight, it doesn't have a local dimming feature. It can dim pixels individually, so bright objects and subtitles are displayed perfectly, with no visible blooming.

The CX has decent SDR peak brightness, enough to combat glare in most rooms. It has an Automatic Brightness Limiter (ABL) that significantly dims the screen when large areas get bright, so that's why the 'Peak 100% Window' and 'Sustained 100% Window' tests result in significantly less brightness.

Like the LG C9 OLED, the CX has a Peak Brightness setting, which changes the way the ABL performs. With this setting turned 'Off', most scenes are between 294 to 308 cd/m², and if the entire screen is bright, the brightness is 166 cd/m². Turning this setting to 'High', which is what we tested with, makes most scenes brighter, but large areas are less bright.

The measurements were taken post-calibration in the 'Expert (Dark Room)' Picture Mode, with OLED Light to '100' and Peak Brightness to 'High.' Before calibration, the TV was slightly less bright.

The CX has decent HDR peak brightness, enough to bring out highlights in HDR. There's quite a bit of variation when displaying different content, and it gets the least bright with large areas, which is caused by the aggressive ABL.

The measurements were taken in 'Cinema' Picture Mode, with OLED Light to '100', Peak Brightness to 'High', and Color Temperature to 'Warm 2.'

Impressive gray uniformity. There's very little dirty screen effect in the center, which is great for sports fans. Uniformity is improved in near-dark scenes, but like some other OLED TVs, there are some faint vertical and horizontal lines which could be visible in near-dark scenes in very dark rooms.

The CX has great viewing angles, and the image remains accurate when viewing from the side. This TV is great for a wide seating arrangement.

Since this OLED TV can turn off individual pixels, the black uniformity is perfect.

Just like the LG C9 OLED, the CX has excellent reflection handling as it has an anti-reflective coating. You shouldn't have any issues placing this in a bright room.

The LG CX OLED has great out-of-the-box color accuracy, much better than the LG C9 OLED. Most colors are slightly inaccurate, but it's hard to notice. The color temperature is warmer than the 6500K target, so colors have a red/yellow tint to them. Overall, the gamma follows the target fairly well, but dark scenes are too dark and some bright scenes are too bright.

After calibration, the color accuracy is nearly perfect. The white balance dE is nearly zero, so shades of gray are displayed almost perfectly. Any color inaccuracies aren't visible without the aid of a colorimeter.

The C9 has an auto-calibration feature, but the CX doesn't have one yet. We'll update the review if one is made available in a firmware update.

You can see our recommended settings here.

This TV upscales 480p content well, with no obvious upscaling artifacts.

The LG CX upscales 720p content, such as from cable boxes, well with no upscaling artifacts that we noticed on past OLED TVs.

1080p content looks almost as good as native 4k content.

Even though it has an RGBW pixel structure, there are no issues displaying 4k content since every pixel has all four sub-pixels in it.

This TV doesn't support an 8k signal.

With an RGBW pixel structure, the LG CX uses four sub-pixels, but all four are never used at the same time. This image shows the red, white, and blue sub-pixels. You can see the green sub-pixel in our alternative pixel photo.

Excellent color gamut. It has near-perfect coverage of the DCI P3 color space used in most HDR content and good coverage of the wider Rec. 2020 color space. It's very slightly improved from the LG C9 OLED.

In 'Cinema' mode, the TV follows the PQ curve well until it rolls off at its peak brightness. In 'Game' mode, it follows the target almost the same, but there's a sharper roll off, which you can see here.

If you find HDR too dim, you can change Dynamic Contrast to 'High' and you can see the EOTF here. Enabling Dynamic Tone Mapping is inconsistent in how it changes the brightness and it made the screen darker when we measured the EOTF.

Despite having an excellent color gamut, the CX's color volume is only decent. It can't produce extremely bright colors, but with a perfect contrast ratio, it can display dark, saturated colors.

Excellent gradient handling, but there's still some banding in most colors. Enabling the Smooth Gradation feature doesn't affect the gradient test, but can reduce banding. Unfortunately, enabling this feature can cause some loss in details.

The CX doesn't show any signs of temporary image retention.

This test is only indicative of short term image retention, and not the permanent burn-in that may occur with longer exposure to static images. We're currently running a long-term test to help us better understand permanent burn-in. You can see our results and read more about our investigation here.

Unfortunately, like most OLED TVs, the CX isn't immune to permanent burn-in. However, we don't expect people who watch varied content to have any issues, but rather it's a problem if there are constant static displays, like if it's used as a PC monitor.

This TV has three features to help burn-in risk. Enabling Screen Shift option, and setting Logo Luminance Adjustment to 'Low' may help with this. There's also an automatic pixel refresher that can be run manually if needed.

If you're concerned about burn-in and you prefer an LED TV, check out the Samsung Q90T.

You can read about our investigation into this here.

The CX has a near-perfect response time, but unfortunately, motion still looks blurry. With the refresh rate at 120Hz, motion blur is noticeable in most content, as you can see here.

Since this TV doesn't have a backlight, it doesn't have a pulse-width modulation (PWM) feature and is technically flicker-free. There's a slight dip in brightness every 8 ms, which coincides with its refresh rate but isn't noticeable.

Update 05/26/2020: 120Hz BFI only works properly in Game mode. Since BFI isn't available when G-SYNC is enabled, to display a 4k @ 120Hz signal with BFI, you have to disable VRR from the source and manually enter Game Mode. In any other picture mode, 4k @ 120Hz signals skip frames, causing duplications when BFI is enabled.

This TV has a black frame insertion (BFI) feature to improve the appearance of motion. To turn it on, set TruMotion to 'User' and OLED Motion on 'High'. The 'Low' and 'Medium' settings offer less aggressive BFI, resulting in a brighter screen.

The LG CX can interpolate lower frame rate content, such as from movies or TV shows, up to 120Hz. This is known as the 'Soap Opera Effect' and helps improve the appearance of motion.

Motion looks clear with no visible artifacting. It interpolates 30fps content a bit better than 60fps content, but this shouldn't be very noticeable with real content.

See here for the settings that control the motion interpolation feature.

Since it has such a fast response time, lower frame rate content can appear to stutter as each frame is held on for longer. This can be noticeable during panning shots.

Enabling the OLED Motion or motion interpolation features can help mitigate this problem.

This TV is able to remove judder from all sources, such as Blu-ray players or native apps. However, there's judder when BFI is enabled, as it flickers at 60Hz.

See our recommended settings to remove judder here.

The LG CX OLED has a 120Hz refresh rate, it supports HDMI Forum's VRR to reduce screen tearing, and it's G-SYNC compatible with newer NVIDIA graphics cards. G-SYNC stops working on all resolutions below 40Hz, and at 120Hz on a 4k resolution, there's some minor glitching.

For G-SYNC to work, the TV must be on 'Game' mode with Instant Game Response Time enabled.

Currently, FreeSync isn't supported, but if it's supported on a future firmware update, we'll update the review.

Update 26/05/2020: Input lag was retested with our "RTX 2070 Super" computer because the laptop had an issue with it. The numbers are all updated, though most haven't changed by any significant margin (0.1-0.5ms).

Really low input lag in 'Game' mode, and it's the lowest with VRR enabled, which is great for gaming. It also stays low with a 4k resolution, which makes it a good choice for Xbox One X or PS4 Pro owners. With an Xbox plugged in, it automatically enables the Auto Low Latency Mode and it turns on HDMI Deep Color Mode, but you have to enable Instant Game Response first for ALLM to work.

Like the LG C9 OLED, the CX displays all common resolutions. For it to display proper chroma 4:4:4, which is important for reading text, it must be on 'PC' mode. However, 4:4:4 doesn't work on 1080p @ 120Hz.

According to the TV's specs, it supports 4k @ 120Hz with proper chroma 4:4:4, but it only works with HDMI 2.1 sources, which we can't test at the moment. We'll retest this when we have an HDMI 2.1 source. However, we were able to get it to 4k @ 120Hz with chroma 4:2:0.

Update 05/24/2020: 4k @ 120Hz is only displayed properly in Game mode. Outside of game mode, it skips frames.