TCL 6 Series/R646 2021 QLED  TV Review

The TCL R646 looks similar to the TCL 6 Series/R635 2020 QLED as it has a silver bottom bezel and the same back panel, but there are a few tweaks. This TV uses different feet that have a more premium feel, and the Google speaker sticks out at the bottom.

Update 08/09/2023: After running on the longevity test for eight months, this TV is now showing signs of image retention or potentially burn-in. It's not visible in most real content, but in near-dark scenes, like this 5% gray uniformity slide, the CNN logo, breaking news banner, and even some text is clearly visible. It's an unexpected result for this type of TV panel. We're looking into it more to determine the nature of the image retention.

Update 02/06/2023: Unfortunately, the brightness of this TV has started to drop after running for two months on our accelerated longevity test.

The TCL R646 features new metal feet that don't take up as much space as those on the TCL 6 Series/R635 2020 QLED. They support the TV well, and there's minimal wobble. There are 3.5 inches from the table to the bottom of the screen so almost all soundbars fit in front of the TV without blocking the screen.

Footprint of the 55-inch TV: 40.35" x 12.48"

The back is entirely plastic, with a glossy top portion that attracts fingerprints easily and a textured bottom half that houses the TV's electronics and inputs. The inputs face to the side, and they're close to one side of the TV, so they're easily accessible even when the TV is wall mounted. There are vents on top of the textured section for airflow. Each of the feet have flaps that you can use for cable management.

This is a bulky TV that won't sit flush against a wall because the bottom part near the inputs sticks out.

It has good build quality, and it feels very similar to the TCL 6 Series/R635 2020 QLED. It's well put together, and it feels sturdy for the most part. The feet are good, as there's almost no wobble. However, the plastic on the back flexes quite easily, and it's noticeable with both the glossy top and the textured bottom.

This TV has an outstanding native contrast ratio. Even with local dimming fully disabled, blacks are deep and don't look washed out at all. The local dimming feature is very effective at reducing black levels in dark parts of the screen.

Thanks to the relatively small size of the dimming zones, there's very little blooming around bright areas of the screen, like the subtitles at the bottom of the test scene or the lights on the roof.

Overall, the lighting zone transitions aren't very noticeable. The TV's processing keeps up well with fast-moving objects, so there's almost no noticeable trailing halo effect.

Switching to 'Game' mode doesn't result in any noticeable difference in dark scene performance.

The TCL R646 has impressive HDR peak brightness. It doesn't get much brighter than in SDR, but bright highlights stand out well in HDR.

These measurements are after calibrating the HDR white point, with the following settings:

• Picture Mode: Movie
• Brightness: Max
• Local Contrast: Low
• Contrast: Max
• Color Temperature: Warm -5

The HDR brightness in Game Mode is excellent. There's no noticeable difference in peak brightness when you start playing a game.

These measurements are with the following settings:

• Picture Mode: Game
• Brightness: Max
• Local Contrast: Low
• Contrast: Max
• Color Temperature: Warm -5

This TV tracks the PQ EOTF well, ensuring most HDR content is displayed at the brightness level intended by the content creator. Interestingly, the TV tracks the EOTF differently depending on the content. Content mastered at 600 nits is brighter than it should be, especially in midtones, and there's a very sharp cutoff at the TV's peak brightness, with no tone mapping. Only content mastered at 4,000 nits shows any signs of tone mapping, and even then it's very minor, so almost all content loses fine details in bright scenes.

The SDR brightness is fantastic, so glare isn't an issue even in very bright rooms. Brightness varies a bit between scenes, but it's not noticeable with most content.

These measurements are after calibration with the following settings:

• Picture Mode: Movie
• Brightness: Max
• Local Contrast: Low
• Contrast: Max
• Gamma: 2.2
• Color Temperature: Warm -5

This TV has a great color gamut for HDR content. It has fantastic coverage of the commonly-used DCI P3 color space, and tone mapping is good, too, so colors look accurate. Coverage of the wider Rec. 2020 is more limited, but it's still decent.

The color volume is good. Thanks to its high peak brightness, it displays bright colors well.

The TCL 55R646 has good accuracy before calibration. Most colors are only slightly inaccurate, and the color temperature is close to the 6500K target. However, white balance is off, which affects shades of gray, and gamma doesn't follow the 2.2 target well, so most scenes are darker than they should be.

The accuracy after calibration is fantastic. Color accuracy and the color temperature improved, and the white balance is much better too. Gamma is perfect for most scenes, but some really bright scenes are a bit too dark.

See our full calibration settings here.

The gray uniformity is good. There aren't many visible issues here, except for some darker edges, but it's hard to tell. Uniformity is better in near-dark scenes.

The black uniformity is fantastic. Without local dimming, there's backlight bleed in the corners, and the local dimming feature helps eliminate that issue.

The TCL 6 Series 2021 has a narrow viewing angle, so it's not well-suited for a wide seating arrangement. The image fades and looks washed out as you move off-center.

The reflection handling is excellent, and it's much better than the TCL 6 Series/R635 2020 QLED. It does a much better job at absorbing light, so combined with the high peak brightness, glare isn't an issue even in very bright rooms.

This TV has excellent gradient handling in HDR. There's a bit of banding in very dark grays, but other than that there are hardly any noticeable issues.

The TV's processing features do a great job of cleaning up low-quality content. There's very little remaining pixelization or macro blocking, but sadly, it loses a lot of fine details in the process.

Unfortunately, this TV has bad sharpness processing with low-resolution or low-bitrate content. Text is hard to read, and fine details are lost.

The optimal sharpness settings for low-resolution or low-bitrate content, with no over-sharpening, are as follows:

• Sharpness: 30

Like most TVs on the market, this TV uses a BGR (Blue-Green-Red) subpixel layout instead of the traditional Red-Green-Blue layout. For video content, it doesn't cause any issues, but if you're planning on using this TV as a PC monitor, this reduces text clarity a bit, although there are easy workarounds for it. You can read about it here.

The TCL R646 has a great overall response time. There's overshoot in most transitions, but the 0-100% transition is slow, resulting in black smearing, which is typical of VA panels.

The TCL R646 uses pulse-width modulation (PWM) to dim its backlight in any picture mode. It flickers at all backlight levels, including at its max. However, the flicker frequency is so high that most people won't notice it.

There's an optional backlight strobing feature, commonly known as black frame insertion. It only flickers at 120Hz and it creates noticeable image duplication, but it doesn't dim the screen much.

There's a motion interpolation feature to interpolate 30 fps and 60 fps content up to 120 fps. It's not bad overall, but it still creates artifacts in fast-moving scenes.

Due to the quick response time, there's some stutter with lower-frame rate content because each frame holds on for longer.

This TV automatically removes 24p judder from any source ensuring a smooth movie-watching experience.

This TV supports variable refresh rate technology with both FreeSync and HDMI Forum VRR sources, including the Xbox Series X and the PS5. Unfortunately, despite its high max refresh rate, low framerate compensation (LFC) doesn't appear to work properly with any source, so there's tearing at low frame rates.

The TCL R646 has very low input lag in Game Mode, ensuring a smooth gaming experience with very little delay between your actions and the image on the TV.

The TCL R646 supports any resolution up to 4k @ 120Hz. It displays chroma 4:4:4 properly with 1080p and 4k signals at 60Hz, which is essential for clear text from a PC. It accepts a 4k @ 120Hz signal in 10 or 12-bit color depth with chroma 4:4:4, but it has the same problem as many other 2021 models, as 4k @ 120Hz isn't displayed properly.

Thanks to its high bandwidth HDMI ports, this TV can take full advantage of the PS5. It also supports Auto Low Latency Mode, so you don't have to worry about switching to 'Game' mode for the lowest input lag when you start gaming.

This TV is fully compatible with everything the Xbox Series S and X have to offer.

The Composite In input needs an adapter, but it doesn't come with one.

The TCL 6 Series Google TV supports eARC, allowing you to pass DTS:X and Dolby Atmos audio formats to a compatible receiver using a single HDMI connection. During our testing, our receiver wasn't properly playing the Dolby Atmos audio file, but the Dolby Atmos logo popped up on the TV. This is likely an issue on our end, and we expect it to work for most people. Since TCL advertises the Dolby Atmos support, we list it as 'Yes', but if you experience the same issue, let us know.

The frequency response is decent. It's similar to the TCL 6 Series/R635 2020 QLED, but it gets louder and has a bit higher deviation, but the sound profile is still well-balanced. It has decent bass, but it's still nothing like a dedicated subwoofer.

The distortion performance is great. Even at the max volume, there's hardly any distortion.

Unlike the TCL 6 Series/R655 2022 QLED, which runs the Roku TV smart interface, the TCL R646 comes with Google TV. TCL uses its own implementation of Google TV, so the settings menu is different than on Sony and Hisense TVs. It may take some time to get used to, but menu navigation feels very smooth.

There are ads on the home page, but we couldn't get a photo of them during testing because they pop in and out, and they're not always there.

The Google Play App store has a massive selection of apps available to download.

The remote is rather simplistic. There's a built-in mic for voice control, and you can ask it to change inputs, open apps, and search for content. However, you can't ask it to change settings. There's also a built-in mic in front of the TV that you can use for the Google Assistant feature.

The power button is on the back of the TV on the right, and you can change inputs with it too. There's the switch to turn the built-in mic on and off above it.

• Remote control (with 2x AAA batteries)
• Power cord
• User guide