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KYY X90A dual monitor review: The portable desktop expansion for laptops and tablets that features two displays

Mobile multi-monitor set! KYY is a manufacturer that offers diverse portable monitor solutions. With the X90A, the manufacturer isn't just offering one display - this solution features two displays which can expand your digital workspace massively. In this short review, you can read about what else the KYY X90A has to offer.
KYY X90A (source: KYY)
KYY X90A (source: KYY)

If you are on the lookout for portable displays for mobile use, then you will probably already have heard of the name KYY. Generally, the manufacturer offers a large palette of external displays which cover a wide range of uses. With the X90A, the manufacturer has released a special display onto the market which basically consists of two 14-inch screens that can be placed to the left and right of a laptop or tablet. Thanks to their two 360-degree hinges, the screens can cover a wide variety of possible use scenarios.

In this review, we will be taking a closer look at the KYY X90A monitor. This is a portable display consisting of two 14-inch screens with a resolution of 1,920 x 1,080 pixels each. In everyday use, your mobile workspace with a laptop can be expanded easily. At the same time, you can also place tablets up to 16 inches in size in the middle of the two screens. Both displays can be connected through one single USB-C cable and after a short setup, they are ready for action.

Further information surrounding KYY monitors can be found here.

The KYY X90A's scope of delivery includes:

  • KYY X90A portable dual monitor
  • USB stick (with display driver)
  • 1x USB-C to USB-C cable
  • 1x USB-C to USB-A cable
  • 1x USB-C to USB-A adapter
  • 5 V/3 A power connection
  • instruction manual

Case and connectivity - High-quality build

The KYY X90A has a solid metal case which gives the device a really high-quality feel. Both of the 14-inch screens can be placed into any position imaginable thanks to their 360-degree hinges. This means you can share your screen in order to present content to the person sitting in front of you. In practical use, this works really well and its bulky metal foot also keeps it really secure.

The KYY X90A features two USB-C ports - one of which is used to supply the device with power and the other is used to transmit picture. You also have the option to simply use one cable for transmission as well as power delivery. The device doesn't have an HDMI or Mini HDMI port. You will also have to make do without separate speakers.

KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)
KYY X90A (source: KYY)

Display - Two times 14 inches in FHD

Subpixel array
Subpixel array
Slightly visible clouding
Slightly visible clouding

The KYY X90A is fitted with two 14-inch displays, each with a resolution of 1,920 x 1,080 pixels. This results in a pixel density of 127 ppi. Our measurements showed average display brightness values of 235 cd/m² (left screen) and 210 cd/m² (right screen). This is slightly dimmer than its competitors but in everyday use, this is enough to work even in brighter surroundings. Its black value is typical for IPS displays, meaning its contrast ratio is also the same as on most IPS panels. It has some subtle issues surrounding clouding, but the shouldn't be noticeable in everyday use. We didn't note any PWM on either of the screens, meaning this shouldn't contribute to tiredness after longer periods of use. 

255
cd/m²
252
cd/m²
242
cd/m²
240
cd/m²
258
cd/m²
224
cd/m²
218
cd/m²
222
cd/m²
207
cd/m²
Distribution of brightness
tested with X-Rite i1Pro 2 (Left Screen)
Maximum: 258 cd/m² (Nits) Average: 235.3 cd/m² Minimum: 41.3 cd/m²
Brightness Distribution: 80 %
Contrast: 956:1 (Black: 0.27 cd/m²)
ΔE Color 3.28 | 0.5-29.43 Ø5
ΔE Greyscale 2.98 | 0.57-98 Ø5.3
66% AdobeRGB 1998 (Argyll 2.2.0 3D)
95.4% sRGB (Argyll 2.2.0 3D)
64% Display P3 (Argyll 2.2.0 3D)
Gamma: 2.14
KYY X90A
1920x1080, 14.00
KYY X90A
1920x1080, 14.00
Uperfect X Pro LapDock
3840x2160, 17.30
Lenovo ThinkVision m14t
1920x1080, 14.00
GMK KD1 Portable Monitor
3840x2160, 14.00
Display
-0%
-3%
-1%
5%
Display P3 Coverage
64
63.8
0%
65
2%
63.6
-1%
69.6
9%
sRGB Coverage
95.4
94.8
-1%
88.2
-8%
95.4
0%
94.4
-1%
AdobeRGB 1998 Coverage
66
65.8
0%
64.5
-2%
65.4
-1%
71.1
8%
Response Times
-5%
-115%
-67%
-280%
Response Time Grey 50% / Grey 80% *
18 ?(4, 14)
18 ?(18, 12)
-0%
35 ?(17, 18)
-94%
15.6 ?(6.4, 9.2)
13%
62 ?(28.4, 33.6)
-244%
Response Time Black / White *
11 ?(3, 8)
12 ?(3, 9)
-9%
26 ?(11, 15)
-136%
27.2 ?(14.8, 12.4)
-147%
45.6 ?(30.8, 14.8)
-315%
PWM Frequency
1000 ?(99)
5000 ?(99)
Screen
-2%
-67%
27%
-18%
Brightness middle
258
228
-12%
248
-4%
310.6
20%
325.3
26%
Brightness
235
210
-11%
232
-1%
295
26%
316
34%
Brightness Distribution
80
67
-16%
84
5%
89
11%
82
3%
Black Level *
0.27
0.25
7%
0.73
-170%
0.23
15%
0.3
-11%
Contrast
956
912
-5%
340
-64%
1350
41%
1084
13%
Colorchecker dE 2000 *
3.28
3.07
6%
6.92
-111%
2.01
39%
4.75
-45%
Colorchecker dE 2000 max. *
5.16
5.22
-1%
8.75
-70%
3.58
31%
8.09
-57%
Greyscale dE 2000 *
2.98
2.47
17%
6.67
-124%
1.9
36%
6.2
-108%
Gamma
2.14 103%
2.15 102%
1.7 129%
2.06 107%
2.31 95%
CCT
6965 93%
6750 96%
7452 87%
6455 101%
6691 97%
Colorchecker dE 2000 calibrated *
1.9
2.19
Color Space (Percent of AdobeRGB 1998)
65.4
Color Space (Percent of sRGB)
94.6
Total Average (Program / Settings)
-2% / -2%
-62% / -60%
-14% / 6%
-98% / -53%

* ... smaller is better

Color space coverage

For our color measurements, we took a look at each of the displays separately. Although, differences between the two were minimal and both screens delivered almost identical results. Within the sRGB color space, we noted the best accuracy, although it can't be depicted in its entirety. Within the AdobeRGB and P3 color spaces, we noted much poorer color accuracy, meaning we wouldn't recommend these displays for professional image or video editing. 

Color space coverage left screen

sRGB
sRGB
DCI P3
DCI P3
AdobeRGB
AdobeRGB

Color space coverage right screen

sRGB
sRGB
DCI P3
DCI P3
AdobeRGB
AdobeRGB

In practical use, both displays have a good display quality. Their matte surfaces prevent mirroring entirely. In summary, the DeltaE 2000 color values we measured were already quite close to the goal value of <3 in the device's delivered state. Lenovo's ThinkVision 14t shows that even more can be done in this aspect.

Grayscale (left screen)
Grayscale (left screen)
ColorChecker (left screen)
ColorChecker (left screen)
Saturation (left screen)
Saturation (left screen)
Grayscale (right screen)
Grayscale (right screen)
ColorChecker (right screen)
ColorChecker (right screen)
Saturation (right screen)
Saturation (right screen)

Display Response Times

Display response times show how fast the screen is able to change from one color to the next. Slow response times can lead to afterimages and can cause moving objects to appear blurry (ghosting). Gamers of fast-paced 3D titles should pay special attention to fast response times.
       Response Time Black to White
11 ms ... rise ↗ and fall ↘ combined↗ 3 ms rise
↘ 8 ms fall
The screen shows good response rates in our tests, but may be too slow for competitive gamers.
In comparison, all tested devices range from 0.1 (minimum) to 240 (maximum) ms. » 24 % of all devices are better.
This means that the measured response time is better than the average of all tested devices (21.4 ms).
       Response Time 50% Grey to 80% Grey
18 ms ... rise ↗ and fall ↘ combined↗ 4 ms rise
↘ 14 ms fall
The screen shows good response rates in our tests, but may be too slow for competitive gamers.
In comparison, all tested devices range from 0.2 (minimum) to 636 (maximum) ms. » 27 % of all devices are better.
This means that the measured response time is better than the average of all tested devices (33.6 ms).

Screen Flickering / PWM (Pulse-Width Modulation)

To dim the screen, some notebooks will simply cycle the backlight on and off in rapid succession - a method called Pulse Width Modulation (PWM) . This cycling frequency should ideally be undetectable to the human eye. If said frequency is too low, users with sensitive eyes may experience strain or headaches or even notice the flickering altogether.
Screen flickering / PWM not detected

In comparison: 53 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 17788 (minimum: 5 - maximum: 3846000) Hz was measured.

The IPS panel delivers excellent image quality during typical use. We hardly noted any color changes and these only happened when looking at the screen from very flat angles, as you can see in the four corner pictures.

The KYY X90A during the viewing angle test
The KYY X90A during the viewing angle test

Pros

+ two 14-inch displays
+ only one cable needed
+ modern design
+ flawless build
+ high-quality materials
+ no PWM

Cons

- display brightness lower than specified
- no bag to protect the device
- low color space coverage

Verdict - Versatile display

KYY X90A review - test sample provided by KYY
KYY X90A review - test sample provided by KYY

The  KYY X90A's two 14-inch displays offer a great alternative to quickly expand your digital workspace. With only one cable, both screens can be powered and in combination with a laptop or tablet, your can quickly create a triple-screen setup on your desk. Unfortunately, our measurements showed that both of the screens' brightness levels were below what was stated by the manufacturer. 

The KYY X90A is a great alternative for a mobile desktop expansion if you are on-the-go and don't want to forgo a multi-monitor workspace.

We liked its modern design and high-quality build in combination with excellent choice of materials. What results from this is excellent stability which is extremely beneficial on a portable display. You can cope with its missing speakers, as you will most likely be using a laptop with the KYY X90A, anyway. Thanks to the displays only requiring one cable, you don't need to worry about an extra power cable being in the way. This makes the device a lot simpler to use in practice.

Currently, the KYY X90A will set you back around US$480. The displays face some in-house competition, as the KYY X90 is an identically-built model which only works with Windows devices. At the end of the day, it's only around US$20 cheaper. The Limink S19 is also a viable alternative which features the same functions as the model we tested. At around US$550, the device is only minimally more expensive.

Transparency

The present review sample was given to the author by the manufacturer free of charge for the purposes of review. There was no third-party influence on this review, nor did the manufacturer receive a copy of this review before publication. There was no obligation to publish this review.

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> Expert Reviews and News on Laptops, Smartphones and Tech Innovations > Reviews > KYY X90A dual monitor review: The portable desktop expansion for laptops and tablets that features two displays
Sebastian Bade, 2023-08-10 (Update: 2023-08-10)