SPECS AT A GLANCE: XIAOMI MI MIX SCREEN 2040×1080 6.4" (362ppi) IPS LCD OS Android 6.0 with Miui 8 CPU Quad-core Qualcomm Snapdragon 821 (two 2.35GHz Kryo cores and two 2.12 GHz Kryo cores) RAM Standard: 4GB "18K" version: 6GB GPU Adreno 530 STORAGE Standard: 128GB"18K" version: 256GB NETWORKING 802.11b/g/n/ac, Bluetooth 4.2, GPS, NFC BANDS GSM: B2, 3, 5, 8

WCDMA: B1, 2, 5, 8

CDMA: BC0

TD-SCDMA: B34, 39

FDD-LTE: B1, 2, 3, 4, 5, 7, 8

TD-LTE: B38, 39, 40, 41 PORTS USB Type-C, 3.5mm headphone jack CAMERA 16MP rear camera, 5MP front camera SIZE 158.8 x 81.9 x 7.9 mm (6.25 x 3.22 x 0.31 in) WEIGHT 209 g (7.37 oz) BATTERY 4400 mAh STARTING PRICE Standard: ~ $516 "18K" version: ~$590 OTHER PERKS Fingerprint sensor, notification LED

Smartphone design has stagnated. If you're using Apple as a measuring stick for the industry, we're going to have three years of iPhones that use an identical case design. If you're going by Samsung, the company hasn't tweaked its front design since the Galaxy S5 in 2014. Google just produced its first self-branded smartphone hardware ever, and it didn't have anything significant to say when it comes to smartphone design either.

Not everyone in the industry seems so content with the status quo, though. For a different take on smartphone design, we look to China, where Xiaomi has just introduced a phone with a jaw-dropping design that maximizes screen real estate above all else. The Xiaomi Mi Mix is the company's look at "the future of smartphones." While it's being called a "concept phone," it's actually for sale for the shockingly low price of $516. Forget about buying it, though—Xiaomi is selling the Mi Mix in China only. Even if you could pay a premium to import it, it sadly lacks important LTE bands for service in the US.

Still... just look at that design! The Mi Mix looks like one of those incredibly unrealistic fan renders, but it's a real phone I was able to spend the last week with. There have been tons of questions about the practicality of something like this and what tradeoffs are involved. Is all-screen actually a good idea? More importantly, is this really the future of smartphones?



Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo





Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

Ron Amadeo

The phone template of the future

If we're talking about major design choices, every modern smartphone can trace its roots back to the original iPhone released in 2007. It has been almost 10 years now, but this device is still used as "the template" for the modern smartphone. You've got the screen in the center of the device, with symmetrical bezels on the top and bottom. Most of the front-facing components go in the top bezel, like the earpiece, auto-brightness, and proximity sensors (later, typically a front-facing camera). The bottom bezel is used for buttons or, sometimes, nothing at all.

This is what we're used to, but it's not necessarily ideal. The screen is the only "useful" real estate on the front of the phone, so really everything that isn't a pixel is wasted space. Engineering realities mean we use the bezels for components both inside and outside the phone. But if we can find a better spot for those components that allows us to make the screen bigger, there's a potential improvement there.

This is exactly what Xiaomi tried to do with the Mi Mix. While most other companies are out making cookie-cutter smartphones, Xiaomi's "concept" phone rethinks how a smartphone should be designed. For the Mi Mix, the company shuffled everything around in the name of maximizing screen real estate and removing wasted space. The front-facing camera and brightness sensor have both been moved to the bottom of the phone, while the proximity sensor and earpiece are completely gone from the front, replaced by high-tech internal solutions.

If you're going to build a "family tree" for the Mi Mix design, past smartphones from Sharp would definitely be in there. In 2014, we reviewed the Sharp Aquos Crystal, one of the few Sharp phones to escape Asia and make it to the wider world. After the mid-range Aquos Crystal, the design moved to higher-end devices with the Sharp Aquos Xx and Aquos Xx2.

Sharp kind of ran into the same problems as the Mi Mix did, but the company never solved them in the same way as Xiaomi. Sharp originally used a weird bone conduction speaker for the earpiece before later scrapping that idea. It then made the top bezel a bit bigger and used a regular earpiece. With the latest version of the "Aquos" line—the Aquos Xx3—Sharp seems to have abandoned its cutting-edge phone design altogether.

How the heck do you make a phone call?

An external earpiece is the major justification for a top bezel on a phone, and it's totally gone in the Xiaomi Mi Mix. There is still an "earpiece speaker" of sorts, but it's on the inside of the device. Rather than slap a speaker on the other side of the display, the company came up with something it calls "cantilever piezoelectric ceramic acoustic technology."

That's a big jumble of words, so let's break it down. "Piezoelectric ceramic" is just a component that converts electrical energy into mechanical energy—you apply voltage and it vibrates. A "cantilever" is a beam attached to something at one end, and judging by Xiaomi's video, it's connected to the piezoelectric as a resonance booster. This enhances the vibration. All this mechanical energy is transferred to the phone's internal metal frame, which then vibrates to create sound.

Vibrating an internal metal frame to create sound means the sound isn't as localized as it would be from a speaker. Sticking your ear anywhere on the top quarter of the phone—front or back—is good enough to pick up noise. There really doesn't seem to be much "directionality" to the sound generation. At a normal listening volume, the sound doesn't travel very far—I'd say it's about as "private" as a normal earpiece. A 3rd party will be able to eavesdrop on your call in a quiet room, but outsiders will struggle to hear your conversation in a noisy area.

At max volume, the "speaker" gets very loud—loud enough that you won't want to have it against your head. At that point, you start to feel the vibrating metal frame through the rest of the phone. With max volume, the phone vibrates about as much as the haptic feedback system makes it vibrate, but again, you don't want to use this at max volume. At a normal level, there's just as much "buzz" as you'd get with a normal speaker.

In practice, the "earpiece speaker" here is excellent, and this feels like an ideal solution for a modern smartphone. It doesn't sound muffled from being "inside" the phone, and the sound quality is about what you would expect from an earpiece speaker, just with a much louder top end. The phone vibrates a bit more at max volume, but that's it for downsides. Even if this were worse than a normal earpiece (again, it isn't), I'd say something like, "as people make fewer and fewer voice calls, dedicating the top of the phone specifically for this purpose makes less and less sense." Xiaomi's solution removes this dead space with basically no tradeoffs. And thanks to the higher volume, I can imagine many voice call users would actually prefer this to a traditional earpiece.

Besides the new earpiece shenanigans, there's also traditional speakerphone functionality using the bottom firing speaker.

Next there's the matter of the proximity sensor, which has also been cut from the top bezel. Normally, smartphones use an infrared proximity sensor to detect your face during a phone call. This way, when you press the phone against your ear, you don't start pressing buttons. The Mi Mix still does this, but instead of an infrared sensor that needs to be mounted on the outside of the phone, Xiaomi uses an ultrasonic sensor that can live behind the screen. Like the speaker, this works perfectly and doesn't use up valuable phone real estate.

Listing image by Ron Amadeo