The Mobile Pixels Duex Lite ($269) differs from most portable monitors in that it’s usually attached to the laptop it’s paired with at the hip—er, hinge. The Duex Lite may also be used as a traditional mobile display when placed at arm’s length from your computer, and Mobile Pixels even provides an optional stand for this purpose (the $35.99 Origami Kickstand). Its primary configuration is to be attached to the back of your laptop and extend all the way out from the right side to form a dual-monitor array. Getting the Duex Lite and its frame to stay fastened to our test Dell laptop proved to be a frustrating—and not altogether successful—task.
MOBILE PIXELS DUEX LITE SPECS
|Panel Size (Corner-to-Corner)||12.5 inches|
|Native Resolution||1920 by 1080|
|Rated Screen Luminance||300 cd/m^2|
|Rated Contrast Ratio||600:1|
|Pixel Refresh Rate||60 Hz|
|Adaptive Sync||Nvidia G-Sync|
|USB Ports (Excluding Upstream)||1|
|VESA DisplayHDR Level||NA|
|Dimensions (HWD)||8.5 by 12.4 by 0.4 inches|
|Warranty (Parts/Labor)||1 year|
A Smart (Perhaps Overly Smart) Design
The Duex Lite’s frame is 8.5 by 12.4 by 0.4 inches (HWD) and weighs only 1.3 pounds. Black (which the business refers to as deep gray) and white are the two matte colors available for the display. The latter was our test unit.
The monitor’s 12.5-inch diagonal screen has a full HD or 1080p (1,920-by-1,080-pixel) resolution and uses in-plane switching (IPS) technology, which is similar to the vast majority of portable displays we’ve tested. It has a 300 nits (candelas per meter squared) brightness rating and a 600:1 contrast ratio.
The frame that houses the Duex Lite panel is attached to the center of the back or lid of your laptop. The panel may slide to the right till it is free of the laptop, and the frame can be moved so its right edge reaches beyond the side of the notebook. A hinge connects the panel’s left edge to the frame, and the display can be left straight or swiveled to slant slightly toward the user—voila, second screen!
The frame is attached to the rear of the laptop with four small circular magnets. They stick to metal plates placed in the plastic frame, each roughly two inches long. The magnets have a little tacky glue on one side and peel-off stickers on the other. An attachment guide (a cardboard sheet) demonstrates where to position the magnets on the frame and how to orient the frame when centering it on the lid and gluing the magnets in place after removing the stickers. After that, you open your laptop, slide the frame to the right, stretch the monitor as far as it will go, and either leave the screen extending straight out or swivel it to your desired angle.
Finally, connect the accompanying three-foot USB-C-to-C cable to the USB-C connection on the panel’s right edge (with a USB-C-to-A adaptor for the computer side, if needed) and you’re ready to go. Your laptop’s screen will be mirrored on the panel. To use the Duex Lite in extended-screen mode, you must first download a driver for Windows or macOS from the Mobile Pixels website. After that, you can expand or rotate the screen using your operating system’s display settings, which can be swiveled from landscape to portrait orientation when the stand is positioned flat on a desk or table.
Two controls are located on the back of the panel, near the USB-C port: a button and a bidirectional arrow switch. When you press the button, a basic onscreen display appears. It has three sliders for backlight brightness, contrast, and saturation that are controlled by the arrow switch. (You get a temperature setting that is set to sRGB by default and includes a few different color temperatures as well as an eye-care mode.)
The Duex Lite is the most similar of the portable displays we’ve tested to the SideTrak Portable Monitor, another 12.5-inch panel that uses a frame attached to the laptop’s lid to drag the screen to the right to form a dual-monitor array. For maximum performance, both require the installation of a driver. However, unlike the SideTrak magnets, which were difficult to remove without damaging the lid of my Dell XPS 13, the Duex Lite magnets did not always stay glued in place (more on this momentarily).
Let’s get back to connecting the frame to the laptop. While the 13.3-inch Duex Plus from Mobile Pixels comes with three sets of magnets (12 in all), our Duex Lite only came with a single set of four. (An additional set of four magnets can be purchased for $19.99.) If you plan to use the Duex Lite with more than one laptop, you’ll definitely need more magnets.) Because the display frame was slightly higher (by about three-quarters of an inch) than my XPS 13, it extended significantly above and below the Dell’s screen and slightly lifted or propped up the back of the laptop when I connected it to the middle of the lid. The magnets were carefully loosened and rearranged, and they thankfully came off without too much difficulty.
Seating the frame slightly above center on the laptop’s lid worked better, however the weight of the frame tended to pull the lid back and tilt the front of the laptop upward unless the angle of the Dell’s screen was properly adjusted. In landscape mode (with the screen extended out to the side) or presentation mode, I had to conclude that my XPS 13 was a little too small to work effectively with the Duex Lite (in which the screen is flipped in its frame to face an audience in front of the presenter, as in the image below).
To test my theory, I borrowed a larger (15.6-inch) Dell laptop from PC Labs, removed the magnets from my XPS 13, positioned the frame in the new laptop’s lid, and pressed it down. I shifted the frame and panel to the right, connected the USB cable, and downloaded and put the Duex driver, tacky side down, on the lid. For a while, everything worked OK, until one of the magnets came loose, and the right side of the Duex screen drooped till its corner touched the desk.
This is unlikely to have happened if I hadn’t already used the magnets twice before attaching the frame to the larger Dell. Each time you pull the magnets free, their adhesive is bound to loosen a little more, until they can no longer hold the frame’s weight. This is all the more reason why you should use extra caution when attaching the frame to the laptop’s lid—been it’s suggested that placing a heavy object on top of the frame and lid for many hours will help keep it glued in place. If you have a 13-inch or smaller laptop, it may be too small or light to handle the Duex screen in landscape mode adequately.
Typical Performance for a General-Purpose Portable Monitor: Testing the Duex Lite
Using a Klein K10-A colorimeter and Portrait Displays’ CalMAN software, I tested color and brightness. We generally use a Murideo SIX-G signal generator to create the patterns we use in our tests, but because the Duex Lite only has a single USB-C port—which powers the display as well as receives signals from the computer—I used the CalMAN software instead.
The Duex Lite’s luminance (brightness per unit area) is rated as 300 nits (candelas per square meter) by Mobile Pixels, however in my tests, it only managed 209 nits at maximum brightness. Nonetheless, this is a common outcome for a portable monitor. Many of the models we tested provide 180 to 220 nits—the 15-inch espresso Display, for example, measured 202 nits. The Lenovo ThinkVision M14 (280 nits), ViewSonic VG1655 (245 nits), and Asus ZenScreen Touch are among the brighter exceptions (240 nits). With a brightness of only 139 nits, the SideTrak Portable Monitor was one of the worst performers we tested.
The contrast ratio of the Duex Lite was 997:1, which is standard for an IPS monitor but far better than the panel’s advertised 600:1.
Most portable displays are tested in the sRGB color space, which is the industry standard for online art and many other applications. Typical general-purpose mobile monitors cover 60 percent to 75 percent of the sRGB gamut, whereas the Lenovo ThinkVision M14 and M14t each covered roughly 97 percent, and the espresso Display covered the entire gamut. The Duex Lite’s sRGB coverage of 72.9 percent isn’t remarkable, but it’s adequate for everyday use. The photos and other photographs I saw had a slight bluish tint to them. (See the color coverage or chromaticity chart above.)
What’s The Difference Between Duex Lite and Duex Plus?
|Duex Lite- white||Duex Lite- Black||Duex Plus||Trio|
|Dimensions||12.4″ x 8.45″ x 0.39″||12.4″ x 8.45″ x 0.39″||12.25″ x 8.46″ x 0.25″||12.25″ x 8.46″ x 0.25″|
|Weight||1.3 lbs (590g)||1.3 lbs (590g)||1.3 lbs (590g)||1.5 lbs|
|Compatible with||Windows and Mac||Windows and Mac||Windows,Mac,NintendoSwitch,DeX||Windows,Mac,NintendoSwitch,DeX|
|USB Ports||One USB Type-C Port||One USB Type-C Port||Two USB Type-C Ports||One USB Type-C Port|
|Material||PC-ABS Plastic||PC-ABS Plastic||PC-ABS Plastic+ Aluminum Alloy||PC-ABS Plastic|
A Portable Monitor That Is Both Versatile and Challenging
The Mobile Pixels Duex Lite is a small-screen portable monitor with numerous configuration modes, the most notable of which is its ability to slide out from its frame and sit next to your laptop’s screen. Before purchasing the Duex Lite, make sure your laptop can support its frame, and carefully follow the instructions for attaching the frame to the lid to avoid the magnets coming away.
For presentations, the Duex Lite can be set to portrait mode or turned away from you. The visual quality was normal for a general-purpose portable display, with traces of a blue tinge commonly visible. The Duex Lite is innovative and adaptable, albeit we had several issues with its trademark dual-screen mode throughout our testing. The Lenovo ThinkVision M14 is a more traditional portable monitor with a larger (14-inch) screen, and its image quality and simple built-in stand are both among the best we’ve seen in a mobile display.