TCL 6 Series/R648 2021 8k QLED TV Review

The TCL R648 has a unique design with a center-mounted stand that's different from other TCL TVs we've tested. It has a borderless design on three sides with a metal border around the panel, giving it a premium look. The back is a bit like the TCL R745 QLED, but it has a center column that stands out when you look at it, but you won't notice it anyways while watching TV.

The stand sticks out from the TV quite a bit, so you'll need a deep table to place it on if you want to put a soundbar. It raises the bottom of the screen about three inches off the table, so most soundbars shouldn't block your view.

Footprint of the 65 inch TV: 18.9" x 12.0".

The back of the TCL R648 is different than most. The top part is glossy plastic that feels good, and the bottom part is generic plastic with etched vertical lines, but it feels a bit cheap. The middle part houses the subwoofer, and that's brushed plastic. There are tracks in the back of the stand that you can use for cable management, but you lose those tracks if you wall-mount the TV.

The TCL R648 has good build quality. It's a solid TV overall, and even though most of it is plastic, it feels nice. The metal borders surrounding the panel give it a premium feel. It wobbles a bit on the stand, but it shouldn't be an issue for most people. The plastic on the back feels a bit cheap, but it doesn't flex much, which is nice.

The TCL R648 has an excellent contrast ratio. Although the native contrast ratio is a bit low for a flagship TV, the full-array local dimming feature improves the contrast even further for deep blacks. Keep in mind that contrast can vary between units.

The TCL R648 has good HDR brightness. Small highlights pop the way the creator intended, and the EOTF follows the PQ curve well for the most part until the slow roll off at its peak brightness.

We tested it in the 'Dark HDR' Picture Mode with TV Brightness set to 'Brighter', Local Contrast on 'High', Color Temperature on 'Warm', and Backlight and Contrast at their max. Like with SDR, these are the brightest settings we measured, including with the EOTF.

The HDR brightness in Game Mode is good. It looks the same as outside of Game Mode, as there aren't any noticeable differences. We tested it using the same settings but in the 'Gaming HDR' Picture Mode.

The TCL R648 has excellent SDR peak brightness. The Mini LED backlighting allows it to get very bright in SDR, so visibility shouldn't be an issue. It gets brightest with small highlights, and it varies a bit between different scenes.

We tested the SDR brightness after calibration in the 'Movie' Picture Mode with TV Brightness set to 'Brighter', Local Contrast on 'High', Color Temperature on 'Warm', and Backlight and Contrast at their max. These settings are the most accurate and the brightest.

The TCL 65R648 has an excellent color gamut, and it displays the wide color gamut needed for HDR content. It has fantastic coverage of the commonly-used DCI P3 color space, but its coverage of the wider Rec. 2020 is a bit more limited.

The color volume is good. Thanks to its wide color gamut, high contrast, and fantastic peak brightness, it displays colors at a wide range of luminance levels.

The out-of-the-box accuracy is excellent. Colors and the color temperature are nearly perfect, and even though the white balance is a bit off, it's still great. Gamma isn't as good, though, as most scenes are over-brightened. Note that accuracy can vary between units.

The TCL 6 Series 8k has fantastic accuracy after calibration. Any inaccuracies in colors and the white balance aren't visible to the human eye. The color temperature is almost exactly at the 6500K target, and gamma is perfect.

See our recommended settings here. All calibration is done through the Roku app and not directly on the TV.

The TCL 6 Series 8k has some uniformity issues with the vertical bands that you see. These are noticeable even with real content with large areas of uniform colors, like in scenes with a sky or sports like hockey. Even with near-dark scenes, you still see the bands. However, this varies between units, so your experience may be different.

The TCL 6 Series 8k has decent black uniformity. There's backlight bleed and clouding without the local dimming feature enabled. The screen is more uniform, and blacks are deeper with the local dimming feature enabled. Keep in mind that uniformity can vary between units.

The TCL R648 has narrow viewing angles, which is normal for a VA panel. The colors washout, and the image looks inaccurate when you move off-center.

The TCL 6 Series 8k has impressive reflection handling, like the TCL 6 Series/R635 2020 QLED. It absorbs light well, but there's a rainbow-like effect when light scatters across the screen.

The TCL 6 Series 8k uses a BGR subpixel layout, which can affect how text is displayed when using the TV as a PC monitor, but it doesn't affect the picture quality. You can read about it here.

The TCL R648 has an excellent response time. Motion looks smooth for the most part, but there's a bit of smearing typical of VA panels, which could be noticeable with black trail behind fast-moving objects in dark scenes. If that bothers you, the Hisense U800GR 8k has a faster response time.

The TCL 65R648 uses pulse width modulation (PWM) to dim its backlight at all brightness levels. It remains the same across the different picture modes and backlight levels. However, it flickers at such a high frequency that you shouldn't notice it.

There's an optional backlight strobing feature, commonly known as black frame insertion. It works with both 60Hz and 120Hz content, but the timing is off, creating image duplication.

We experienced issues where the screen kept flickering on and off when we tried enabling the BFI feature with our PC connected, as you can see here and here. This only happened with the Backlight set to anything above '70', and it worked properly at '70' and below. It only worked once with the Backlight set to '100' and the refresh rate at 120Hz, and that's when we were able to take the photo. As mentioned, this only happened with the PC connected, and the BFI worked fine with gaming consoles and Netflix, so it's likely a bug with our setup. Let us know if you experience the same thing.

The TCL R648 has a motion interpolation feature to interpolate 30 and 60 fps content up to 120 fps. Like with the TCL R745 QLED, it looks good with slow-paced content like scenes with dialogue, but there are artifacts and halos in busy scenes.

Due to the quick response time, lower-frame rate content can appear to stutter because each frame is held on longer. You can try to enable the motion interpolation feature if it bothers you.

The TCL R648 automatically removes 24p judder from any source, which helps with the appearance of motion with movies. We experienced an issue with 1080i @ 60Hz content from an Android box when connected to HDMI 1 and 2; the TV said to connect to HDMI 3 or 4 for optimal viewing because there was flickering with HDMI 1 and 2. We tried changing the HDMI Mode to 'HDMI 1.4', but nothing changed with the flickering. HDMI 1 and 2 still remove judder, but there's this flickering that doesn't exist with HDMI 3 and 4.

The TCL 6 Series 8k supports variable refresh rate technology to reduce screen tearing. It supports FreeSync natively and is G-SYNC compatible.

The TCL R648 has low input lag as long as you're in Game Mode. Its 60Hz input lag is a bit higher than some other TVs, but input lag is very low at 120Hz.

The TCL 65R648 supports most common resolutions natively up to 8k @ 60Hz, but you need to create a custom resolution for 1440p @ 60Hz signals. It displays proper chroma 4:4:4 with all its supported resolutions except 1440p @ 120Hz because the letters look blurry. It automatically goes into PC Mode when you connect a PC, so it displays chroma 4:4:4 on its own.

We received a report that a gray test pattern causes color artifacts when using the TV as a PC monitor with an 8k resolution. We noticed the same color artifacts with the test pattern on our TV after updating the firmware to version '10.5.0 build 4210-AH', but only this specific pattern caused such major issues when using the TV as a PC monitor. Scrolling through web pages and documents looks fine. There's a bit of pixel inversion and dithering happening that we mentioned in the 8k Input section, but it's minor, and you won't notice it unless you're looking for it. If you're using it as a PC monitor with an 8k resolution, expect some content to look off, but it won't be all the time.

The TCL R648 doesn't have any issues displaying signals from the PS5 and Xbox Series X. It has an Auto Low Latency Mode enabled by default, and it switches the TV into Game Mode when you launch a game from a compatible device.

We couldn't find out the max bandwidth of the HDMI 2.1 inputs because we were having issues with the CRU software, but they support 4k @ 120Hz and 8k @ 60Hz signals.

HDMI 4 supports eARC, meaning you can pass high-quality Dolby Atmos audio signals to a compatible receiver through a single HDMI connection. It supports DTS formats via ARC, but it doesn't support DTS:X over eARC.

The TCL R648 has a decent frequency response. It has a well-balanced sound profile except for a dip between the treble and mid, meaning some vocals may sound a bit more distant. It gets loud, so it's a good choice for a noisy environment. It has a dedicated subwoofer on the back, but its bass extension is still just okay, so it doesn't deliver the real punch that you're looking for.

The distortion performance is okay. There isn't much distortion at moderate listening levels, but it gets more noticeable at its max volume. However, not everyone may hear it, and it depends on the content.

The TCL R648 comes with Roku TV built-in, which is user-friendly, and the menu navigation feels smooth. This Fall theme was enabled by default, which is why it's different than other Roku TVs we've tested, but you can change it in the settings. There was only one bug we encountered when connected to a PC, which we explained in the Black Frame Insertion section.

There are ads on the home page, and there's no way to disable them.

Roku's app store has a great selection of apps you can download.

The TCL 6 Series 8k comes with a redesigned Roku remote that looks a bit like the remote that comes with the TCL 6 Series/R646 2021 QLED, which has Google TV instead. The R648's remote has a few shortcut buttons to popular streaming services, and it's bigger than previous models. It has a mic for voice control that allows you to change inputs, open apps, and search for content, but you can't change settings like the Backlight.

The TCL 6 Series 8k has a single button below the inputs on the right side to turn the TV On/Off and change inputs.

• Remote (with 2x AAA batteries)
• User guide