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TCL 4 Series/S425 2019 TV REVIEW

Usage Ratings - Version 1.3
7.3
Mixed Usage
Value for price beaten by
: Vizio V Series 2019
6.4
Movies
7.0
TV Shows
7.1
Sports
8.4
Video Games
6.6
HDR Movies
7.9
HDR Gaming
8.1
PC Monitor
Type : LED
Sub-Type
:
VA
Resolution : 4k

The TCL 4-Series S425 Roku Smart TV is a decent TV with decent picture quality. It can display deep blacks thanks to its high native contrast ratio, but lacks a local dimming feature to improve dark room performance. It has good reflection handling, but limited brightness both in SDR and in HDR, and doesn't perform well in a bright room. It does not have a wide color gamut and can't deliver HDR content with vivid colors and bright highlights. It has a very fast response time, and fast-moving content has only minimal blur trail. The input lag is very low, and this will please gamers and PC users.

Test Results
Design 6.5
Picture Quality 7.1
Motion 6.8
Inputs 9.6
Sound Quality 6.3
Smart Features 7.5
Pros
  • Very low input lag, great for games.
  • Great smart features.
Cons
  • Can't get bright enough.
  • Image degrades when viewed at an angle.

Check Price

Market Context

The TCL 4-Series S425 is a budget VA panel TV. It sits below the TCL S517. It is the replacement of last year's TCL S Series S405. The TCL S425 is comparable to most budget models of other manufacturers like the Samsung RU7100, the LG UK6300, or Vizio E Series 2018.

6.5

Design

Curved : No

The TCL S425 has a decent design. It has a wide plastic stand that supports it well, but the TV will wobble if nudged. The back of the TV is very similar to last year's TCL S405. The top half is metallic, whereas the bottom part and the body are plastic. It is not very thick and will not protrude much if wall-mounted. The build quality is decent, and you should not have any issues with it.

Stand

The stand of the TCL S425 is plastic and supports the TV well. It is black and almost as wide as the TV. Last year's TCL S405 had a very similar stand, but with a silver finish. The legs cannot be reversed, and the TV will wobble if nudged.

Footprint of the 55" model stand: 32.2" x 7.3"

Back
Wall Mount : VESA 100x100

The back of the TV is plain. The top part is metal, whereas the bottom half and the rest of the body are plastic. The TCL S425 is available in many sizes and not all of them fit the same VESA mount size. Check here to see which VESA mount size is suitable for each TV size.

There is no cable management.

Borders
Borders : 0.59" (1.5 cm)

The borders are plastic, very plain, and have an average thickness.

Thickness
Max Thickness : 2.91" (7.4 cm)

The TV has an average thickness when viewed from the side, and it will not stick out much if wall-mounted.

Temperature
Maximum Temperature
:
96 °F (35 °C)
Average Temperature
:
85 °F (29 °C)
6.5 Build Quality

The build quality is decent. There are no gaps or loose ends, and although the TV does not have a premium look, you should have no issues with it.

7.1

Picture Quality

The TCL 4-Series has a decent picture quality. It has a high native contrast ratio that delivers deep blacks in a dark room but unfortunately, it lacks a local dimming feature to further improve dark room performance. The S425 cannot get very bright and it is more suitable for a dim room. It can handle reflections well but has narrow viewing angles and it is not suitable for a room with a wide seating arrangement. It doesn't have a wide color gamut and can't deliver HDR content with vivid colors and highlights that pop. Finally, the gray uniformity is decent, but some sports fans might find the amount of dirty screen effect bothersome.

9.1 Contrast
Native Contrast
:
6054 : 1
Contrast with local dimming
:
N/A

The native contrast ratio of the TCL S425 is excellent. Blacks look deep in a dark room and this great for the picture quality. It is a significant improvement over last year's TCL S405. Unfortunately, the TV lacks a local dimming feature and can't improve the appearance of blacks further.

0 Local Dimming
Local Dimming
:
No
Backlight
:
Direct

The TCL S425 does not have a local dimming feature. The video is for reference only.

5.4 SDR Peak Brightness
SDR Real Scene Peak Brightness
:
168 cd/m²
SDR Peak 2% Window
:
142 cd/m²
SDR Peak 10% Window
:
177 cd/m²
SDR Peak 25% Window
:
177 cd/m²
SDR Peak 50% Window
:
177 cd/m²
SDR Peak 100% Window
:
177 cd/m²
SDR Sustained 2% Window
:
141 cd/m²
SDR Sustained 10% Window
:
177 cd/m²
SDR Sustained 25% Window
:
177 cd/m²
SDR Sustained 50% Window
:
177 cd/m²
SDR Sustained 100% Window
:
177 cd/m²
SDR ABL
:
0.017

Disappointing SDR peak brightness for the S425. The performance is in the same ballpark figure as last year's TCL S405. This TV is okay for a moderately lit room, but it is not suitable for a bright room. Except for small highlights, the brightness remains unchanged no matter the scene, and this is good.

We performed our measurements after calibration with picture mode set to ‘Movie.’ Different settings may produce a brighter picture.

You can check our settings page to see how to set the brightness.

5.1 HDR Peak Brightness
HDR Real Scene Peak Brightness
:
191 cd/m²
HDR Peak 2% Window
:
199 cd/m²
HDR Peak 10% Window
:
206 cd/m²
HDR Peak 25% Window
:
207 cd/m²
HDR Peak 50% Window
:
207 cd/m²
HDR Peak 100% Window
:
207 cd/m²
HDR Sustained 2% Window
:
199 cd/m²
HDR Sustained 10% Window
:
206 cd/m²
HDR Sustained 25% Window
:
207 cd/m²
HDR Sustained 50% Window
:
207 cd/m²
HDR Sustained 100% Window
:
207 cd/m²
HDR ABL
:
0.003

The TCL S425 has poor HDR peak brightness and can't display bright HDR highlights. Just like in SDR, the brightness remains unchanged no matter the scene. This is a similarly bad performance to last year's TCL S405.

We performed our measurements without calibration with picture mode set to ‘dark HDR' and 'brighter.' Different settings may produce a brighter picture.

You can check our settings page to see how to set the HDR settings.

6.8 Gray Uniformity
50% Std. Dev.
:
2.926 %
50% DSE
:
0.203 %
5% Std. Dev.
:
3.116 %
5% DSE
:
0.112 %

The TCL 4-Series has decent gray uniformity. The corners are a little darker, and some dirty screen effect can be seen at the center of the screen, which might disappoint sports fans. Unfortunately, in near-dark scenes, there are noticeable uniformity issues on both sides of the screen, but the uniformity is better in the center.

4.8 Viewing Angle
Color Washout
:
19 °
Color Shift
:
23 °
Brightness Loss
:
27 °
Black Level Raise
:
15 °
Gamma Shift
:
12 °

The S425 has bad viewing angles. This is typical for VA panel TVs. As soon as you move off center, the image loses accuracy as gamma shifts, black levels rise, and colors start to wash out. This is similar behavior to last year's TCL S Series S405. This TV is not a good choice if you have a room with a wide seating arrangement. If viewing angles are important to you, then check out the LG UK6300.

7.3 Black Uniformity
Native Std. Dev.
:
1.142 %
Std. Dev. w/ L.D.
:
N/A

The black uniformity on the TCL S425 is decent. There is visible backlight bleed at the edges which, however, is only noticeable when you watch a very dark scene in a dark room.

7.8 Reflections
Screen Finish
:
Semi-gloss
Total Reflections
:
5.3 %
Indirect Reflections
:
0.6 %

The handling of reflections on the TCL 4-Series is good. The TV has a semi-glossy finish that limits indirect reflections. You should have no problem placing this TV in a room with many small light sources. However, if you place it across from a large window, reflections might become bothersome.

5.9 Pre Calibration
White Balance dE
:
3.36
Color dE
:
5.69
Gamma
:
2.33
Color Temperature
:
6130 K
Picture Mode
:
Movie
Color Temp Setting
:
Warm
Gamma Setting
:
2.2

Unfortunately, the out-of-the-box color accuracy for the TCL S425 is disappointing. The errors we measured both in the white balance dE and in the color dE are large. The color error especially might be noticeable by many. The TV is clipping reds and whites when not in PC mode. In order to see a significant improvement, you would have to lower the contrast a lot, but we do not recommend it as it affects the picture quality. The color temperature is warmer than the 6500K target, and thus the image has a slight reddish and yellow tint. The gamma does not follow the target, and thus dark scenes are significantly darker than they should be.

9.1 Post Calibration
White Balance dE
:
0.50
Color dE
:
2.10
Gamma
:
2.22
Color Temperature
:
6532 K
White Balance Calibration
:
11 point
Color Calibration
:
Yes
Auto-Calibration Function
:
No

After calibration, the accuracy of the TCL S425 is excellent. It is almost impossible to spot any remaining white balance inaccuracies. On the other hand, some color inaccuracies, mainly in the reds and the greens, remain after calibration and some enthusiasts might be able to spot them. Just like with other TCL TVs, calibration is only possible via the mobile app, but you still need to use a colorimeter.

You can see our recommended settings here.

8.0 480p Input

Upscaling of low-quality content such as DVDs is good.

8.0 720p Input

720p sources such as cable are upscaled well. Details remain clear.

9.0 1080p Input

Upscaling of 1080p content such as Blu-rays or game consoles looks good with no obvious issues.

10 4k Input

Native 4k content has no issues.

7.2 Color Gamut
Wide Color Gamut
:
No
DCI P3 xy
:
80.17 %
DCI P3 uv
:
86.24 %
Rec 2020 xy
:
57.74 %
Rec 2020 uv
:
63.53 %

The TCL S425 does not have a wide color gamut. The true color gamut of the TV is shown by the maximum red, green, and blue in the Rec 2020 gamut picture. Unfortunately, all other colors in the Rec 2020 picture and all the P3 colors are undersaturated. We assume that this happens because the TV is prioritizing brightness over color accuracy because it is so dim. These tests were done at 75% brightness stimulus. When we performed the same tests at a dimmer 50% stimulus the accuracy was much better as can be seen in the following images:

The TV's EOTF is dimmer than the PQ curve, and at about 50% stimulus gray it starts to roll off very early to smooth the transition to the TV's low peak brightness. The same performance is found in 'Game' mode as you can see here.

If you wish to make the HDR brighter, you can set gamma to 1.8 in the phone app. This will result in this EOTF which is a little brighter than before.

6.3 Color Volume
Normalized DCI P3 Coverage ITP
:
70.9 %
10,000 cd/m² DCI P3 Coverage ITP
:
22.8 %
Normalized Rec 2020 Coverage ITP
:
55.7 %
10,000 cd/m² Rec 2020 Coverage ITP
:
17.8 %

The TCL 4-Series has mediocre color volume. The TV can't display very dark saturated colors. When the TV is trying to display bright P3 colors, the gamut narrows significantly, probably due to the TV's tone mapping prioritizing brightness over color accuracy because the TV is so dim.

8.3 Gradient
Color Depth
:
10 Bit
Red (Std. Dev.)
:
0.099 dE
Green (Std. Dev.)
:
0.109 dE
Blue (Std. Dev.)
:
0.084 dE
Gray (Std. Dev.)
:
0.109 dE

The gradient of the TCL S425 is very good. Very little banding is visible, especially in darker shades of green and gray, but nothing major. Overall, it performs slightly worse than last year's S405 and a little better than the Samsung NU7100.

10 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 temporary image retention on the TCL S425.

10 Permanent Burn-In Risk
Permanent Burn-In Risk
:
No

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

Pixels
6.8

Motion

The motion handling of the TCL S425 is decent. It has a very fast response time, so there is only a little blur behind fast-moving content. Below a certain brightness level, it uses PWM to dim the backlight, which might bother some people. There are no extra features to enhance motion handling, and unfortunately, the TV can only remove judder from true 24p sources.

8.9 Response Time
80% Response Time
:
4.7 ms
100% Response Time
:
12.1 ms

The response time of the S425 is excellent. Only a short trail follows fast-moving objects. In dark scenes, however, some smearing may be present due to the longer transition between darker shades, such as from 0% to 20%. Nonetheless, this is an improvement over last year's S405.

4.0 Flicker-Free
Flicker-Free
:
No
PWM Dimming Frequency
:
120 Hz

The TV uses PWM to dim the backlight, but only below 17/100 backlight setting. Backlight PWM dimming results in a 120Hz flicker which might bother some people. This is very different behavior than the TCL S405, which used PWM dimming throughout the entire range of its backlight levels.

5.4 Black Frame Insertion (BFI)
Optional BFI
:
No
Min Flicker for 60 fps
:
120 Hz
60 Hz for 60 fps
:
No
120 Hz for 120 fps
:
N/A
Min Flicker for 60 fps in Game Mode
:
120 Hz

Just like last year's S405, the S425 can't reduce its flicker frequency to 60Hz to make the image look crisper. However, at lower brightness levels, its 120Hz PWM backlight does help somewhat to make motion look clearer.

0 Motion Interpolation
Motion Interpolation (30 fps)
:
No
Motion Interpolation (60 fps)
:
No

The S425, just like last year's S405, doesn't provide any motion interpolation feature.

7.2 Stutter
Frame Hold Time @ 24 fps
:
29.6 ms
Frame Hold Time @ 60 fps
:
4.6 ms

The TCL 4-Series has a little stutter due to the very fast response time that results in a higher frame hold time of 24p content, like movies. Unfortunately, the TV does not offer any option to help you reduce stutter.

5.6 24p Judder
Judder-Free 24p
:
Yes
Judder-Free 24p via 60p
:
No
Judder-Free 24p via 60i
:
No
Judder-Free 24p via Native Apps
:
No

Unfortunately, the TCL S425 can only remove judder from 24p movies when they are played from 24p sources like DVDs or Blu-rays. 24p movies played from 60p/60i sources like cable, satellite boxes, or even through the native apps will have some judder.

There is no specific feature or option to turn on so as to remove judder from 24p movies on 24p sources. The TV detects it and displays the movie properly.

0 Variable Refresh Rate
Native Refresh Rate
:
60 Hz
Variable Refresh Rate
:
No
4k VRR Maximum
:
N/A
4k VRR Minimum
:
N/A
1080p VRR Maximum
:
N/A
1080p VRR Minimum
:
N/A
1440p VRR Maximum
:
N/A
1440p VRR Minimum
:
N/A
VRR Supported Connectors
:
N/A

The S425 has a 60Hz panel and does not support more advanced features such as FreeSync.

9.6

Inputs

The S425 has a very low input lag that will please gamers. It supports the most common resolutions and can display proper chroma 4:4:4 as long as you set the input icon to 'Computer.' When you connect a PC to the TV, it automatically switches and locks to PC mode.

9.8 Input Lag
1080p @ 60 Hz
:
12.9 ms
1080p @ 60 Hz Outside Game Mode
:
48.6 ms
1440p @ 60 Hz
:
12.8 ms
4k @ 60 Hz
:
13.0 ms
4k @ 60 Hz + 10 bit HDR
:
12.9 ms
4k @ 60 Hz @ 4:4:4
:
13.0 ms
4k @ 60 Hz Outside Game Mode
:
29.7 ms
4k @ 60 Hz With Interpolation
:
N/A
8k @ 60 Hz
:
N/A
1080p @ 120 Hz
:
N/A
1440p @ 120 Hz
:
N/A
4k @ 120 Hz
:
N/A
1080p with Variable Refresh Rate
:
N/A
1440p with VRR
:
N/A
4k with VRR
:
N/A
8k with VRR
:
N/A
Auto Low Latency Mode (ALLM)
:
Yes

The TCL S425 has excellent low input lag. To get the lowest input lag, you need to switch the Game Mode to 'On.' The Game Mode is available in all picture modes. During our test, there we times where we had to turn off the TV or disconnect and reconnect the HDMI to get the lowest input lag. We assume that this was due to an issue with the HDMI handshake. When we changed to 'Game Mode' it went to an in-between state that had a higher input lag. This should not be a common issue to most users.

When you connect a PC, it is always detected automatically, and you do not have to do anything special to display proper chroma subsampling 4:4:4. To display 4:4:4 through other sources, change the icon to Computer.

8.3 Supported Resolutions
1080p @ 60 Hz @ 4:4:4
:
Yes
1080p @ 120 Hz
:
No
1440p @ 60 Hz
:
Yes (native support)
1440p @ 120 Hz
:
No
4k @ 60 Hz
:
Yes
4k @ 60 Hz @ 4:4:4
:
Yes
4k @ 120 Hz
:
No
8k @ 30 Hz or 24 Hz
:
No
8k @ 60 Hz
:
No

The TCL S425 supports most common resolutions at 60Hz, but it can't display any resolution at 120Hz. Chroma 4:4:4 works properly with a PC even if the icon on the input is not set to 'computer.' For other sources, change the icon to 'computer.'

To set an HDMI port to full bandwidth 2.0, follow this sequence: Settings > TV Inputs > HMDI1 (for port 1) > HDMI Mode > HDMI 2.0.

When you connect a PC, the TV switches automatically to PC mode. There is no way to use the TV with a PC and be outside of PC mode.

Input Photos
Total Inputs
HDMI : 3
USB : 1
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
SD/SDHC : 0
Inputs Specifications
HDR10
:
Yes
HDR10+
:
No
Dolby Vision
:
No
HLG
:
No
3D
:
No
HDMI 2.0 Full Bandwidth
:
Yes (HDMI 1,2,3)
HDMI 2.1
:
No
CEC : Yes
HDCP 2.2 : Yes (HDMI 1,2,3)
USB 3.0
:
No
Variable Analog Audio Out : Yes
Wi-Fi Support : Yes (2.4 GHz, 5 GHz)

The S425 supports CEC, but we were unable to make it work with our Blu-ray player.

Audio Passthrough
ARC
:
Yes (HDMI 3)
eARC support
:
No
Dolby Atmos via TrueHD via eARC
:
No
DTS:X via DTS-HD MA via eARC
:
No
5.1 Dolby Digital via ARC
:
Yes
5.1 DTS via ARC
:
Yes
5.1 Dolby Digital via Optical
:
Yes
5.1 DTS via Optical
:
Yes

If you wish to enable Dolby over ARC, you must select the Dolby D/DTS setting.

6.3

Sound Quality

The TCL has a mediocre sound. It can't get very loud but is able to produce clear and intelligible dialogue. Unfortunately, its bass is lacking and doesn't have any body or thump to it. The TCL S425 has no room correction system but its distortion performance is decent. For a better sound, dedicated speakers or soundbars are recommended.

6.2 Frequency Response