TCL 6 Series 2018 TV Review

Tested using Methodology v1.5
Updated Mar 06, 2020 at 03:56 pm
TCL 6 Series 2018 Picture
Mixed Usage
Value for price beaten by
: TCL 6 Series/R635 2020 QLED
TV Shows
Video Games
HDR Movies
HDR Gaming
PC Monitor
This TV was replaced by the TCL 6 Series/R625 2019
Type LED
Resolution 4k

The TCL 6 Series 2018 is a very good 4k TV for a wide range of usages. It has good dark scene performance due to the full-array local dimming and high native contrast so blacks appear deep even in a dark room. It's also great for HDR, as it has great brightness. Although it can produce a wider color gamut than Rec. 709, it isn't as wide as other great HDR TVs. It also has an excellent low input lag for gamers, and unlike the 2017 TCL P607 it can flicker the backlight to clear up fast motion and interpolate low frame rate content.

The TCL 6 Series 2018 is also known as the R615 or R617 depending on the manufacturer variant.

Our Verdict

7.7 Mixed Usage

Very good TV for mixed usage. The R617 is a versatile TV that's good for pretty much everything. There are some gray uniformity issues, which makes it a less good choice for sports due to the dirty screen effect, and the image degrades rapidly when viewed at an angle, which is bad for those with wide seating.

  • Very bright in HDR and SDR.
  • Excellent low input lag for gaming.
  • Good local dimming and native contrast produce deep blacks.
  • Picture quality degrades at an angle.
  • Uniformity could be better.
8.0 Movies

Great TV for watching movies in a dark room. The TCL 6 Series has an excellent native contrast ratio, and the local dimming feature is decent for dimming darker areas of the screen. There may be some issues with uniformity, depending on your specific panel.

7.6 TV Shows

Good TV for watching TV in a brightly lit room. The R617 is able to get very bright and can overcome most glare, but the reflection handling isn't as good as high-end TVs, so some direct glare might be bothersome. The picture quality also degrades rapidly when viewed at an angle, which is bad for those with wide seating.

7.4 Sports

The TCL R617 is a good TV for watching sports. It has a great response time that makes fast-moving motion look clear. This TV can get really bright and it does a decent job with reflection handling, so you can still place it in a bright room. The gray uniformity is mediocre, so there's visible dirty screen effect that you'll notice when watching sports. Additionally, the viewing angles are poor, so it's not a good TV to watch with a big group of people.

7.7 Video Games

The 55R617 is amazing for playing video games. Gamers will enjoy the incredibly low input lag and great response time, plus it has a black frame insertion feature to help reduce motion blur. This TV has a great contrast ratio, resulting in deep blacks if you game in the dark. Unfortunately, if you're looking for an immersive gaming experience, the sound quality is disappointing. However, this TV displays 1080p content, such as from older consoles, almost as well as 4k content.

8.0 HDR Movies

Great TV for watching HDR movies. The TCL 6 Series gets very bright in HDR, and the excellent native contrast and decent local dimming make for a good dark room viewing experience. It also has a good wide color gamut, but it isn't as wide as higher-end TVs.

7.5 HDR Gaming

Impressive TV for HDR gaming. The R617 has excellent low input lag in game mode, and it has a great response time so games are free of annoying trails. The native contrast and good color gamut help games look their best. It doesn't support a 120Hz input, so some gamers might be disappointed.

7.4 PC Monitor

Good TV for use as a PC monitor. The 6 Series 2018 supports chroma 4:4:4 when in PC mode, so text looks sharp and clear. It has low input lag and a good response time which keeps it responsive. The viewing angle is quite limited, so if sitting too close, the edges of the screen might fade and lose detail. There are also many reports of uniformity issues, so using it for web browsing might be a problem for some people.

  • 7.7 Mixed Usage
  • 8.0 Movies
  • 7.6 TV Shows
  • 7.4 Sports
  • 7.7 Video Games
  • 8.0 HDR Movies
  • 7.5 HDR Gaming
  • 7.4 PC Monitor
  1. Update 5/21/2020: Converted to Test Bench 1.5.
  2. Update 2/21/2020: Converted to Test Bench 1.4.
  3. Update 2/28/2019: Converted to Test Bench 1.3.
  4. Update 1/9/2019: We retested the DTS passthrough with the new firmware and now it works properly. The corresponding review section has been updated.
  5. Update 1/7/2019: Added a note about the 75R615.


Test Results

Curved No

The R617 has a simple design, but it looks a bit bulky mainly because of its thick bezels. It looks like other TCL TVs we've tested, and overall it feels like it has a solid build to it. The stand is very wide, so you'll need a big table to hold it, but it supports the TV well.


Like most TCLs, the TCL 6 Series has a stand that is nearly the full width of the TV. You'll need a very wide table to put it on. It's made of metal and feels strong and sturdy. This change in material is a nice departure from the plastic feel of older TCL models.

Footprint of the 55" TV stand: 47.8" x 10.6"

The legs can also be reversed, in which case the stand measures 28.5" x 10.6".

Wall Mount VESA 200x200

The rear of the TV is simple. The top half is metallic and the body is plastic.

There's no cable management, so it can look a bit messy for those who enjoy clean setups with hidden cables.

Borders 0.47" (1.2 cm)

The borders of the TCL 6 Series look decent. They're metallic and have the same finish as the stand legs.

Max Thickness 2.95" (7.5 cm)

The TCL 6 Series is comprised of two sections: the electronics compartment, and the panel section which is square and has a bulky feel to it. Even though the overall thickness isn't bad, it'll stick out a little if wall-mounted.

Build Quality

Decent build quality that feels solid and the TV doesn't have any loose parts on it. Its successor, the TCL 6 Series/R625 2019 has improved build quality.

We have received many reports of varying gray uniformity issues between units, which may be indicative of the build quality or quality control.

Picture Quality
Picture Quality
Native Contrast
5182 : 1
Contrast with local dimming
6052 : 1

As is the case with most VA panels, the 6 Series 2018 has a fantastic contrast ratio. The R617 is able to produce deep, inky blacks when viewed in dark rooms.

The local dimming feature further improves the contrast ratio, making it a great choice for dark room viewing.

Picture Quality
Local Dimming
Local Dimming

The local dimming on the TCL R615/617 series is decent, and it can produce deeper dark scenes which is very noticeable especially when viewed in a dark room.

On the other hand, there's some obvious clouding around the moving objects. This is because of the inherent limitations of FALD technology and should not worry most people.

Update: The text has been updated to better explain why we see some clouding.

Picture Quality
SDR Peak Brightness
SDR Real Scene Peak Brightness
701 cd/m²
SDR Peak 2% Window
881 cd/m²
SDR Peak 10% Window
984 cd/m²
SDR Peak 25% Window
1161 cd/m²
SDR Peak 50% Window
876 cd/m²
SDR Peak 100% Window
676 cd/m²
SDR Sustained 2% Window
874 cd/m²
SDR Sustained 10% Window
979 cd/m²
SDR Sustained 25% Window
1155 cd/m²
SDR Sustained 50% Window
874 cd/m²
SDR Sustained 100% Window
675 cd/m²

Great SDR peak brightness; it performs well in a bright room. The TV boosts the bright sections of the screen when other areas are dimmer. This is shown by how the smaller window tests are brighter than the larger ones.

This is an improvement from 2017's TCL P605/607 and it's much better than the brightness of competing TVs like the Samsung NU7100 and Vizio M Series 2017. It's also a bit brighter than the newer TCL 6 Series 2019 R625.

Picture Quality
HDR Peak Brightness
HDR Real Scene Peak Brightness
840 cd/m²
HDR Peak 2% Window
908 cd/m²
HDR Peak 10% Window
1009 cd/m²
HDR Peak 25% Window
1173 cd/m²
HDR Peak 50% Window
879 cd/m²
HDR Peak 100% Window
674 cd/m²
HDR Sustained 2% Window
903 cd/m²
HDR Sustained 10% Window
1006 cd/m²
HDR Sustained 25% Window
1165 cd/m²
HDR Sustained 50% Window
871 cd/m²
HDR Sustained 100% Window
673 cd/m²

The TCL 6 Series has great HDR peak brightness. Bright highlights in HDR content will be shown fairly bright, very close to the level of 1000-4000 cd/m² they're intended to be.

Overall, the HDR brightness is much better than the TCL P605/607 which is great.

Picture Quality
Gray Uniformity
50% Std. Dev.
4.670 %
50% DSE
0.229 %
5% Std. Dev.
1.797 %
5% DSE
0.127 %

Mediocre gray uniformity on the 55R617. There's clear darkening around all four corners and there's visible dirty screen effect, which is noticeable with fast-moving objects. Even during dark scenes, the black isn't uniform across the screen. However, this result varies between units.

Picture Quality
Viewing Angle
Color Washout
21 °
Color Shift
32 °
Brightness Loss
29 °
Black Level Raise
15 °
Gamma Shift
14 °

The viewing angle is poor. Blacks and colors shift rapidly as you move away from the front, and the brightness drops quickly as the angle increases a few degrees.

As with most TCLs we've reviewed, it's most suitable for a narrow viewing environment.

The Sony X720E is a better choice for a wide viewing angle.

Picture Quality
Black Uniformity
Native Std. Dev.
1.006 %
Std. Dev. w/ L.D.
0.746 %

The black uniformity of the TCL 6 Series is good. Although there's some clouding in the native black uniformity, the performance improves when local dimming is enabled. This only reduces clouding around the test cross.

Picture Quality
Screen Finish
Total Reflections
5.7 %
Indirect Reflections
0.7 %
Calculated Direct Reflections
5.0 %

The R617 has a semi-gloss finish that works well in diffusing reflections across the screen. However, when viewed in a bright room, the reflections may be somewhat distracting especially if the source is facing the TV.

This model has better reflection handling than the newer TCL R625.

Picture Quality
Pre Calibration
White Balance dE
Color dE
Color Temperature
5979 K
Picture Mode
Color Temp Setting
Gamma Setting

Good color accuracy pre-calibration. Most of the colors on the TCL R617 still appear fairly accurate, but because the color temperature is below the target, most colors will be closer to red and yellow. The gamma curve follows the target really well, so most scenes should appear at their correct brightness.

Picture Quality
Post Calibration
White Balance dE
Color dE
Color Temperature
6484 K
White Balance Calibration
11 point
Color Calibration
Auto-Calibration Function

As is the case with most TVs, the R617 has near-perfect color accuracy post-calibration. With the exception of the color blue, most colors are extremely accurate. The gamma curve is exactly at the 2.2 target, but the color temperature wasn't able to fully reach its target, so some colors are still closer to red/yellow.

See our recommended settings here.

Picture Quality
480p Input

Lower resolution 480p content looks good and is displayed without any obvious issues.

Picture Quality
720p Input

720p content is displayed well, without any issues.

Picture Quality
1080p Input

1080p content like Blu-rays and non-4k games looks almost as good as native 4k.

Picture Quality
4k Input

There are some artifacts visible with 4k content due to the sub-pixel dimming. This performs similarly to the P607 (see here), but shouldn't be an issue for most people and is mostly noticeable when used as a PC monitor.

This type of dithering is uncommon, and is only seen on some TCL TVs, including the S517 and R617. Most people won't notice it much, but occasionally it causes artifacts when it interferes with spatial dithering in games such as this green or purple shadow. (Note: the images are from the S517, but we expect them to be the same on the 6 Series.)

Update 29/05/2018: We've received a report that the 49" S515/S517 has similar crosshatching to the S405, as seen here, and we expect this to be the same in the R615/R617. This will bother some people especially when used as a PC Monitor.

Picture Quality
8k Input

This is a 4k TV that can't display 8k content.

Picture Quality

The pixel structure is quite different from the P607, but there are still artifacts visible with native 4k content as seen in the 4k input box.

Picture Quality
Color Gamut
Wide Color Gamut
DCI P3 xy
88.57 %
DCI P3 uv
90.93 %
Rec 2020 xy
64.25 %
Rec 2020 uv
67.38 %

The TCL 6 Series 2018 has a good color gamut, but it's slightly worse than the P607. It supports a wide color gamut, but it isn't as wide as other HDR TVs. HDR will look good, but bright outdoor scenes will lack some detail due to the TV's limited green reproduction.

Note that for this test, a PC was used as a pattern generator. Like many other TCL TVs, the TV detects the PC from the AVI infoframe and automatically switches to a PC mode which behaves a little bit differently. Using an HDFury Integral to mask the AVI infoframe results in a color gamut in the same ballpark, but slightly lower at around 65.8% Rec. 2020 uv.

The TV's Movie EOTF curve follows our input stimulus almost perfectly, but it rolls off sharply as it hits the TV's peak brightness. The PC and Game EOTFs are nearly identical, which is great.

Picture Quality
Color Volume
Normalized DCI P3 Coverage ITP
83.9 %
10,000 cd/m² DCI P3 Coverage ITP
48.7 %
Normalized Rec 2020 Coverage ITP
63.2 %
10,000 cd/m² Rec 2020 Coverage ITP
36.5 %

The 55R617 has decent color volume. In the P3 volume, it covers the gamut well; this is a great improvement over the TCL P607. In both color volumes, the darker colors aren't displayed very well, and blues don't get very bright.

Picture Quality
Color Depth
10 Bit
Red (Std. Dev.)
0.121 dE
Green (Std. Dev.)
0.116 dE
Blue (Std. Dev.)
0.099 dE
Gray (Std. Dev.)
0.123 dE

Good gradient performance on the TCL 6 Series 2018. There's some small banding in dark red, dark green, and dark gray, but nothing major and this shouldn't be a problem.

Picture Quality
Temporary Image Retention
IR after 0 min recovery
0.00 %
IR after 2 min recovery
0.00 %
IR after 4 min recovery
0.00 %
IR after 6 min recovery
0.00 %
IR after 8 min recovery
0.00 %
IR after 10 min recovery
0.00 %

There's no image retention on this TV. As always, this is good news for gamers and PC users who might use this TV as a monitor.

Picture Quality
Permanent Burn-In Risk
Permanent Burn-In Risk

We don't expect VA panels to experience permanent image retention, as the VA panel in our long-term test appears immune.

Response Time
80% Response Time
6.3 ms
100% Response Time
12.4 ms

Great response time with a minimal blur trail behind fast-moving objects. Most transitions won't have any visible overshoot.

PWM Dimming Frequency
480 Hz

There's a backlight flicker on the R617, but it flickers at 480Hz, which is barely noticeable. This is a significant improvement over the 120Hz flicker on the TCL P Series/P607 2017. The TV mainly dims the backlight through PWM, although there's some amplitude dimming as well.

Black Frame Insertion (BFI)
Optional BFI
Min Flicker for 60 fps
60 Hz
60 Hz for 60 fps
120 Hz for 120 fps
Min Flicker for 60 fps in Game Mode
60 Hz

The R617 has an optional black frame insertion feature that can adjust the backlight flicker to help clear up motion by introducing flicker.

This can be enabled by going to Options->Advanced Picture Settings and turning LED Motion Clarity On.

The TV can flicker as low as 60Hz, even in game mode, but there are some strange results. It appears to flicker each color individually, resulting in visible duplications of different colors, as seen here. This is also noticeable when moving around with BFI enabled.

Motion Interpolation
Motion Interpolation (30 fps)
Motion Interpolation (60 fps)

The TV can interpolate lower frame rate content as high as 60 fps. Motion can look a little strange to some people when enabled, this is commonly known as the Soap Opera Effect. This doesn't work when connected to a PC, and there's no way to bypass this as this TCL automatically detects when it's connected to a PC.

Motion interpolation is a new feature on the TCL R617, and it can be enabled by going to the Advanced Picture Settings menu, and setting Action Smoothing to either Off, Low, Medium, or High.

Frame Hold Time @ 24 fps
29.3 ms
Frame Hold Time @ 60 fps
4.3 ms

The R617 can display most content without stutter, but there's some noticeable stutter when playing 24p content - like Blu-ray movies. This is mostly noticeable in wide-panning shots.

24p Judder
Judder-Free 24p
Judder-Free 24p via 60p
Judder-Free 24p via 60i
Judder-Free 24p via Native Apps

The TV is judder free when playing native 24p content from a Blu-ray player. To remove judder from other sources, Natural cinema must be enabled in the Advanced Picture Settings menu. This is a significant improvement over all other TCL TVs we've reviewed.

Variable Refresh Rate
Native Refresh Rate
60 Hz
Variable Refresh Rate
G-SYNC Compatible
4k VRR Maximum
4k VRR Minimum
No VRR support
1080p VRR Maximum
1080p VRR Minimum
No VRR support
1440p VRR Maximum
1440p VRR Minimum
VRR Supported Connectors
No VRR support

The TCL 6 Series doesn't support any of the Variable Refresh Rate technologies like AMD FreeSync. We tested on a PC with an AMD Radeon RX 580.

Input Lag
1080p @ 60 Hz
17.6 ms
1080p @ 60 Hz Outside Game Mode
152.4 ms
1440p @ 60 Hz
17.6 ms
4k @ 60 Hz
19.2 ms
4k @ 60 Hz + 10 bit HDR
19.6 ms
4k @ 60 Hz @ 4:4:4
19.2 ms
4k @ 60 Hz Outside Game Mode
122.8 ms
4k @ 60 Hz With Interpolation
148.1 ms
8k @ 60 Hz
1080p @ 120 Hz
1440p @ 120 Hz
4k @ 120 Hz