TCL 6 Series 2018 TV Review

Updated May 18, 2018 at 11:31 am
TCL 6 Series 2018 Picture
Usage Ratings - Version 1.3
Mixed Usage
Value for price beaten by
: Hisense H8F
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 (R617/R615) 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 is also great for HDR, as it has a 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 last year's TCL P607 it can flicker the backlight to clear up fast motion and interpolate low frame rate content.

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

Our Verdict

8.0 Mixed Usage

Very good TV for mixed usage. It is a versatile TV that is 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.

See our Mixed Usage recommendations
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.

See our Movies recommendations
7.7 TV Shows

Good TV for watching TV in a brightly lit room. The TV is able to get very bright and can overcome most glare, but the reflection handling is not 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.

See our TV Shows recommendations
7.6 Sports

Decent TV for watching sports. The fast response time means motion will be fluid, and the TV can get bright to overcome ambient glare. There are many reports of serious issues with gray uniformity, so there may be more dirty screen effect than we measured depending on your panel. The TV also has a narrow viewing angle so the best picture is reserved for those directly in front of the TV.

See our Sports recommendations
8.6 Video Games

Excellent TV for gaming. The TCL 6 Series has excellent low input lag as long as Game mode is on. The fast response time means games are fluid and there is very little motion blur, so fast games look their best.

See our Video Games recommendations
8.1 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 dimmings 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.

See our HDR Movies recommendations
8.4 HDR Gaming

Impressive TV for HDR gaming. The TV 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.

See our HDR Gaming recommendations
8.3 PC Monitor

Good TV for use as a PC monitor. The TV 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 use for web browsing might be a problem for some people.

See our PC Monitor recommendations
  • 8.0 Mixed Usage
  • 8.0 Movies
  • 7.7 TV Shows
  • 7.6 Sports
  • 8.6 Video Games
  • 8.1 HDR Movies
  • 8.4 HDR Gaming
  • 8.3 PC Monitor
  • 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
  1. Update 2/28/2019: Converted to Test Bench 1.3. Learn more about our versioned test bench system here.
  2. 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.
  3. Update 1/7/2019: Added a note about the 75R615.


Test Results

Market Context
Curved No

The design of the TCL 6 Series is decent, similar to most TCL TVs we have tested. The stand is wide but very stable, and the TV feels slightly bulky due to the square design of the TV's bezel. It will not stand out as a premium TV but is quite functional.


Like most TCLs, the TCL 6 Series has a stand that is nearly the full width of the TV. You will need a very wide table to put it on. It is made of metal and feels strong and sturdy. This change in material is nice 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 is 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 are 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 is not bad, it will stick out a little if wall mounted

Maximum Temperature
95 °F (35 °C)
Average Temperature
84 °F (29 °C)

The TCL 6 Series stays quite cool. In fact, it scored one of the lowest average temperatures of the TVs we tested in 2017-8.

It has two big vents, one on the bottom and one in the back allowing the temperature on the screen to be fairly uniform.

Build Quality

The build quality of the TCL 6 Series feels decent. There are no loose panels or gaps, and the TV seems to have a solid construction.

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

The TV has amazing contrast. It matches many of the high-end TVs we have tested. Although it does not reach the contrast levels of the TCL P607/605 models it certainly follows their legacy of excellent contrast.

The contrast increases with local dimming since the full array panel manages to darken the blacks without sacrificing much brightness. This is great for dark room performance.

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 is 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 last year's TCL P605/607 and it is 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 last year's 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 %

Unfortunately, the TCL 6 Series we tested has mediocre uniformity. There is noticeable dirty screen effect throughout the screen, and the corners are noticeable darker than the rest of the screen. This varies between units, so your results may be better than ours.

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 have reviewed it is 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 is some clouding in the native black uniformity, the performance improves when local dimming is enabled. This reduces clouding only around the test cross.

Picture Quality
Screen Finish
Total Reflections
5.7 %
Indirect Reflections
0.7 %

The TCL 6 Series 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

Out of the box, the TCL 55R617 has good color accuracy. The color temperature is quite warm, so everything is slightly red/yellow. Gamma already follows our target well. White balance and color dE are low enough that most people won't notice much of a difference.

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

The TCL 6 Series has to calibrated with the TCL app. Calibration is very easy to do and both the white balance and the CMS respond very well to calibration. The blue dE was not as easy to correct, but remains accurate.

Post calibration, the TV is one of the most accurate TVs on the market. Gamma follows the target curve perfectly, and white balance and color dE are nearly perfect. The overall color temperature is a bit warm still, but very close to the target 6500K.

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 have 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
Color Gamut
Wide Color Gamut
DCI P3 xy
88.57 %
DCI P3 uv
90.93 %
Rec 2020 xy
64.25 %
Rec 2020 uv
67.39 %

The TCL 6 Series has a good color gamut, but slightly worse than last year's 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 a 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 TCL 6 Series 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 are not 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

The performance is comparable to the 2017 TCL P605/P607 model although not quite as good. There is some small banding visible in dark reds, greens and grays, but no major banding in any color. Those minor imperfections are not likely to ruin a good HDR movie watching experience.

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 is 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.

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.

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

Very good response time. Most of the blur in the above photo is due to persistence. Pixel response is similar to the P607. There is almost no overshoot in any of the transitions.

PWM Dimming Frequency
480 Hz

The TCL 55R617 mainly dims the backlight through PWM, although there is some amplitude dimming as well. The backlight flicker is hardly noticeable, as it flickers at 480Hz, a significant improvement over the 120 Hz flicker on the P607.

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 TCL 6 Series has a new 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 60 Hz, 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 does not work when connected to a PC, and there is no way to bypass this as this TCL automatically detects when it is connected to a PC.

Motion interpolation is new this year 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 TCL 6 Series can display most content without stutter, but there is 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 have reviewed.

Variable Refresh Rate
Native Refresh Rate
60 Hz
Variable Refresh Rate
G-SYNC Compatible
4k VRR Maximum
4k VRR Minimum
1080p VRR Maximum
1080p VRR Minimum
1440p VRR Maximum
1440p VRR Minimum
VRR Supported Connectors

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
1080p with Variable Refresh Rate
1440p with VRR
4k with VRR
8k with VRR
Auto Low Latency Mode (ALLM)

The TCL 6 Series has excellent low input lag, as long as Game mode is enabled. With Game mode disabled, input lag is extremely high. 1080p and 4k input lag is very similar. The TV is a 60Hz panel, as such 120Hz input is not supported.

For use as a PC monitor, the TV automatically detects when it is connected to a PC. If it doesn't automatically detect it, changing the input label to Computer will enable PC Mode. For the lowest input lag in PC mode, Game mode must also be enabled.

Supported Resolutions
1080p @ 60 Hz @ 4:4:4
1080p @ 120 Hz
1440p @ 60 Hz
Yes (forced resolution required)
1440p @ 120 Hz
4k @ 60 Hz
4k @ 60 Hz @ 4:4:4
4k @ 120 Hz
8k @ 30 Hz or 24 Hz
8k @ 60 Hz

The TV supports most resolutions without issue. For use as a PC Monitor, PC mode must be enabled; either by the TV's auto-detection or by changing the input label to Computer. The TV must be in PC mode for chroma 4:4:4 to work.

Input Photos

All of the inputs are directed out the side. There is an included mini break out cable for composite input, but no component input.

Unlike the P607, there is no headphone output on the remote. To connect headphones, the audio output on the side of the TV is the only option.

Total Inputs
Digital Optical Audio Out 1
Analog Audio Out 3.5mm 1
Analog Audio Out RCA 0
Component In 0
Composite In 1 (incl. adapter)
Tuner (Cable/Ant) 1
Ethernet 1
DisplayPort 0
IR In 0

Unlike the P607, there is no headphone output on the remote. To connect headphones, the audio output on the side of the TV is the only option.

Inputs Specifications
Dolby Vision
HDMI 2.0 Full Bandwidth
Yes (HDMI 1,2,3)
HDMI 2.1
HDCP 2.2 Yes (HDMI 1,2,3)
USB 3.0
Variable Analog Audio Out Yes
Wi-Fi Support Yes (2.4 GHz, 5 GHz)

For the audio return channel to work, CEC must be enabled in Settings -> System -> Control other devices (CEC) -> ARC (HDMI 3).

For 5.1 passthrough on the ARC, the Audio Mode must be set to Auto in the Settings -> Audio menu, with S/PDIF and ARC set to "Dolby D, DTS". With other settings no sound was getting passed through to our receiver, not even stereo PCM.

DTS passthrough doesn't work, which is unexpected since it did on last year's P607.

Update 06/05/2018: To support HDR on HDMI ports connected to an Xbox One, the HDMI ports must be manually set to HDMI 2.0 as the Auto setting will not automatically switch to HDMI 2.0 due to a detection issue.

Update 01/09/2019: We retested the DTS passthrough with the new firmware and now it works properly.

Audio Passthrough
Yes (HDMI 3)
eARC support
Dolby Atmos via TrueHD via eARC
DTS:X via DTS-HD MA via eARC
5.1 Dolby Digital via ARC
5.1 DTS via ARC
5.1 Dolby Digital via Optical
5.1 DTS via Optical