The TCL 6 Series/R648 2021 8k QLED is TCL's first 8k Roku TV. It's a new model part of the flagship 6 Series lineup with the TCL 6 Series/R646 2021 QLED, which has Google TV instead, and the 4k TCL 6 Series/R635 2020 QLED. This TV features Mini LED backlighting, providing greater control over the full-array local dimming. The 8k resolution helps provide better image clarity, but 8k content is still limited, and it doesn't display 4k content as well as a native 4k TV. It's future-proof for gaming because it has two HDMI 2.1 inputs, so you can use it for 4k @ 120Hz or 8k @ 60Hz gaming with the PS5 and Xbox Series X. Lastly, the built-in Roku is great if you don't want to buy external streaming devices, as it's user-friendly and has a large selection of apps available through the app store.
The TCL R648 is great for most uses. It's great for watching SDR and HDR movies in a dark room because it displays deep blacks and has a decent local dimming feature, but it crushes blacks too much. It's great for watching shows or sports because it has excellent peak brightness and reflection handling, but it has narrow viewing angles. Gamers should also appreciate the low input lag, quick response time, HDMI 2.1 inputs, and variable refresh rate support for an excellent gaming experience.
The TCL R648 is great for watching movies in dark rooms. It has a VA panel with a high contrast ratio, and the Mini LED local dimming feature is decent. It helps improve the contrast, but it crushes blacks and causes the loss of details with bright highlights. The TV removes 24p judder from any source, which helps with the appearance of motion. It upscales 1080p and 4k content well, but there's some dithering with 4k content. Also, it doesn't display 480p content well, so it's not a good choice for watching DVDs.
The TCL R648 is great for watching TV shows in a bright environment. Visibility shouldn't be an issue because it gets bright enough to combat glare and has excellent reflection handling. It upscales 720p and 1080p content without issue, and the built-in Roku TV has a great interface. However, it doesn't upscale 480p content well as it looks bad, so it's not a good choice for watching older shows or DVDs. It also has narrow viewing angles, so the image looks inaccurate when viewing from the sides.
The TCL R648 is great for watching sports. Fast-moving content in sports looks good because it has a quick response time. It has high peak brightness and excellent reflection handling, making it a great choice for viewing in bright rooms. However, it has narrow viewing angles, so it's not good for watching with a large group of friends. Our unit also has uniformity issues that can be noticeable with uniform colors, like in sports with large playing surfaces, like hockey or basketball.
The TCL R648 is excellent for gaming. It has a bunch of gaming-oriented features like two HDMI 2.1 inputs and variable refresh rate support to reduce screen tearing. Input lag is low, and it has a quick response time for smooth motion. It's great for dark room gaming because it has an excellent contrast and decent local dimming, but the local dimming crushes too many blacks, causing a loss in bright details.
The TCL R648 is great for watching HDR movies. It delivers deep blacks thanks to its high contrast and decent Mini LED local dimming feature, but it crushes blacks in scenes with small highlights. However, it still gets bright enough in HDR to make most highlights pop, and it displays a wide color gamut. It has good gradient handling, but you may see some banding with shades of similar color.
The TCL 65R648 is excellent for HDR gaming. It has low input lag and a quick response time for a smooth and responsive gaming experience. It also has supports HDMI 2.1 and VRR. HDR content looks great because it gets bright, displays a wide color gamut, and has a high contrast ratio. Its Mini LED local dimming feature is decent, but it crushes blacks, so small details are lost.
The TCL R648 is great to use as a PC monitor. It has HDMI 2.1 inputs that allow it to display signals up to 8k @ 60Hz, including with chroma 4:4:4. It has low input lag for a responsive desktop experience. Visibility shouldn't be an issue in a well-lit room because it gets bright enough to combat glare and has excellent reflection handling. Sadly, it has narrow viewing angles, so the image looks washed out at the sides if you sit too close.
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 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 Mini LED full-array local dimming feature is decent. It's better overall than the TCL R745 QLED, and it does a better job at delivering deep blacks than the TCL 6 Series/R646 2021 QLED. However, it crushes blacks in dark scenes to the point where you lose details. It's hard to see the stars in the opening shot of our real content video. You can use the 'Vivid' Picture Mode to make those stars pop more, but that results in a less accurate image.
The positive trade-off for the black crush is that there's minimal blooming around bright objects or subtitles. Blooming is worse with our test pattern, but it's not as bad with real content. The local dimming looks best when viewed directly in front as there's more blooming from the side. The algorithm handles fast-moving objects fairly well, but you may see some trail behind transitioning or the golf ball effect in front of them.
The 65 inch model has 160 zones, and the 75 inch version has 240 zones. The video above is filmed with Local Contrast set to 'High', which is our recommended setting.
The local dimming looks the same in Game Mode as outside of it.
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 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 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 R648 does a bad job at upscaling 480p content, like from DVDs. It doesn't have scaling issues like the TCL 6 Series/R646 2021 QLED, but content looks blocky as if you see the pixels. It's not suggested for watching DVDs.
The TCL 6 Series 8k upscales 720p content well, making it a great choice for watching cable boxes.
The TCL R648 upscales 4k content well, but there's some dithering in shadows. However, it's hard to see.
Like with the Samsung QN800A 8k QLED, the TCL R648 displays native 8k content well, but there are dithering issues. It's most noticeable in the shadows, but it's still hard to see in the photo.
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 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 gradient handling is good. There's some banding in the grays and greens, and the blues look the best. The Noise Reduction setting doesn't do much to improve the gradients in the test pattern or real content.
There are no signs of temporary image retention on our unit of the TCL 6 Series 8k, but this can vary. You can see the vertical bands that are caused by the uniformity issues.
We don't expect VA panels to experience permanent image retention, as the VA panel in our long-term test appears immune.
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. There's no way to tell if it supports HDMI Forum VRR because the Xbox Series X supports both FreeSync and HDMI Forum VRR, so it's unknown which one is actively working.
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. We couldn't get proper VRR input lag readings, which is something we experienced with the TCL R745 QLED and the Samsung QN90A QLED. We're looking into this issue, and we'll update the review once we fix it.
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.
We tested the 65 inch TCL 6 Series 8k (65R648), and for the most part, we expect our review to be valid for the 75 inch model (75R648), too. You can see the differences between them below. This model is only available in the United States, and it's part of the 6 Series lineup that includes the 4k TCL 6 Series/R646 2021 QLED, but our results aren't valid for that model because it performs differently.
|Size||Model Code||Local Dimming Zones|
If someone comes across a different type of panel or if their TCL R648 doesn't correspond to our review, let us know, and we'll update the review. Note that some tests, like gray uniformity, may vary between units.
The TCL R648 is a great 8k TV. It delivers great picture quality with its deep blacks, decent local dimming, and high peak brightness. Gamers should also enjoy extra features like HDMI 2.1 and variable refresh rate. In terms of its value, it's one of the better 8k TVs we've tested because it's cheaper than the Samsung QN800A 8k QLED for better dark room performance. However, 8k content isn't readily available, and there are cheaper 4k TVs available.
The Hisense U8G and TCL 6 Series/R648 2021 8k QLED are both great TVs with different resolutions. The Hisense is a 4k TV, while the TCL is 8k, so it supports higher resolution signals. Although the TCL has Mini LED backlighting and the TCL doesn't, the Hisense has a better local dimming feature because it doesn't crush blacks as much and has better uniformity. The Hisense also gets brighter in HDR, delivering a better HDR experience.
The LG C1 OLED and the TCL 6 Series/R648 2021 8k QLED are different types of TVs. The LG is a 4k TV with an OLED screen, so it has much better contrast, better uniformity, wider viewing angles, and a quicker response time than the LED panel on the TCL. Since the LG is a 4k TV, it displays native 4k resolution better than the 8k TCL because it doesn't have to upscale it. On the other hand, the TCL's higher resolution supports 8k signals, and it gets much brighter, so highlights pop more in HDR. The TCL also doesn't suffer from the risk of permanent burn-in like the LG.
The TCL 6 Series/R648 2021 8k QLED and the TCL 6 Series/R646 2021 QLED are part of the same 6 Series lineup, but they're different TVs. The R648 is an 8k model with Roku TV, while the R646 is a 4k TV with Google built-in. They each have VA panels with high contrast, and even though their local dimming features are both decent, they perform differently. The one on the R648 crushes blacks with minimal blooming and the one on the R646 helps brighten highlights, but it doesn't improve the contrast with real content much. They both don't upscale 480p well, but that's because the R646 can't display the proper aspect ratio, and the R648 is just bad at it.
The Samsung QN90A QLED is better overall than the TCL 6 Series/R648 2021 8k QLED. They both have Mini LED backlighting, and the Samsung gets much brighter, especially in HDR, and it has a better local dimming feature because there's less blooming. the Samsung has better viewing angles because of the 'Ultra Viewing Angle' technology, so it's a better choice for watching shows or sports in a wide seating area, and it has better reflection handling. The TCL is an 8k TV, so it supports higher-resolution signals than the Hisense, but the Hisense also displays native 4k content better because it doesn't have to upscale it.
The TCL 6 Series/R648 2021 8k QLED and the TCL 6 Series/R635 2020 QLED are part of the same lineup, but they have different features. The R648 has an 8k resolution, while the R635 is 4k. The 8k resolution is supposed to deliver clear images, but the R635 still does a better job at displaying 480 and native 4k content. The R648 improves in a few ways, like the better local dimming, HDMI 2.1 inputs, and better reflection handling, but the R635 still gets brighter in HDR.
The Samsung QN900A 8k QLED and the TCL 6 Series/R648 2021 8k QLED are both 8k TVs. They both feature Mini LED backlighting, and even though the local dimming feature on the Samsung does a better job at improving the contrast, they're both decent overall. The Samsung gets brighter in HDR, and it has wider viewing angles thanks to the 'Ultra Viewing Angle' layer. The Samsung also does a better job at upscaling 480p content, making it a better choice for watching DVDs.
The TCL 6 Series/R648 2021 8k QLED and the Hisense U800GR 8k are similar 8k TVs with Roku TV. The TCL uses Mini LED backlighting that lets it get much brighter, especially in HDR, and it also has a higher contrast ratio. They have similar gaming features, but the Hisense has a slightly quicker response time. The Hisense is only available in a 75 inch size, while the TCL is available in 65 and 75 inches, but other than that, the differences are minimal.
The Samsung QN800A 8k QLED and the TCL 6 Series/R648 2021 8k QLED are both great. They have similar features with HDMI 2.1 inputs, VRR support, Mini LED backlighting, and a VA panel, but there are a few differences between them. The TCL has a better contrast ratio because the Samsung has 'Ultra Viewing Angle' technology that improves the viewing angles at the cost of the contrast. The Samsung has many more local dimming zones that improve the contrast, but the local dimming is better overall on the TCL because there's less blooming. Because of this, the TCL delivers a better HDR experience, but the Samsung still gets brighter in HDR.