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Sonim XP1300 Core review: Sonim XP1300 Core

Sonim XP1300 Core

Kent German Former senior managing editor / features
Kent was a senior managing editor at CNET News. A veteran of CNET since 2003, he reviewed the first iPhone and worked in both the London and San Francisco offices. When not working, he's planning his next vacation, walking his dog or watching planes land at the airport (yes, really).
Kent German
7 min read


Sonim XP1300 Core

The Good

The Sonim XP1300 Core has an extremely rugged design that can take a lot of abuse. It offers easy-to-use controls and satisfying audio clarity.

The Bad

The Sonim XP1300 Core has few high-end features. Call volume is too low.

The Bottom Line

The Sonim XP1300 Core doesn't bring a lot of features and call volume could be higher, but it more than fits the bill as an exceptionally durable cell phone.

It's not often that we're encouraged to break a cell phone that we're reviewing. Most of the time, actually, we're expected to return a handset completely unharmed. Yet, Sonim takes a different, and welcome, approach. Not only does the company challenge us to break its phones, but it helps us try and do so.

That's just what happened with Sonim's latest model, the XP1300 Core. When company reps dropped off the phone at CNET's offices, they were good enough to bring concrete, dry ice, and a bucket of antifreeze. We'll get to specifics of our torture tests in the Design section, but you can be sure that the XP1300 Core, like the earlier Sonim XP3, is built to last. Less impressive was the feature set. Though the XP1300 Core delivers the essentials, there's no camera and there aren't high-end productivity apps. Worse, call quality wasn't quite up to par. The audio clarity was satisfying, but the call volume wasn't sufficient. The GSM XP1300 is sold unlocked for $399.

All that durability comes at a price, of course: the large, bulky XP1300 handset may defy most definitions of portability. At 4.96 inches long by 2.36 inches wide by 0.98 inch deep and 6.52 ounces, it will fit in only the biggest pockets. Honestly, a belt clip is probably the best way to carry a phone like the XP1300 Core. And if that isn't conspicuous enough, you can get it in a striking yellow-and-black color scheme.

The XP1300 Core is big, but it's as sturdy as they come.

The handset's candy-bar shape mimics that of previous Sonim models. The entire handset is wrapped in a tough rubber and fiberglass casing and the battery cover is secured by screws. Protective flaps keep moisture out of the twin 3.5mm ports on the left side. Though the top jack accommodates a standard wired headset, the bottom jack forces you to use Sonim's proprietary connection for charging the phone and syncing it with a PC. Sonim includes the necessary cables in the box, but that's still inconvenient.

The display measures 2 inches and is covered by Gorilla Glass. That makes it resistant to scratches, even if you try to drive a nail into the screen (as we did). The 320x240-pixel resolution isn't eye-popping, but it's more than suitable for this phone. Colors are bright, graphics are relatively sharp, and the revamped menu interface is easy to use. You can change the display's screensaver and wallpaper.

You'll have to remove the screws to access the battery and memory card. On the phone's top end is a flashlight.

The navigation controls are about the same as on the XP3, though Sonim threw in dedicated Back and Clear controls. The four-way toggle has directional buttons, and we like that the OK control is covered in a rough-textured material. You'll also find two soft keys and the Talk and End/Power keys. They're a tad slick, but it's not a big deal. The redesigned dial-pad keys give you enough space for a comfortable texting experience. The backlighting is bright, as well, though the text on the keys is rather small. Users with visual impairments might want to check it out in person before buying.

The XP1300 Core has comfortable keys and controls.

The beefy volume rocker sits on the phone's right spine above a control that activates the bright flashlight on the rear side. A programmable shortcut key is on the left side below the aforementioned 3.5mm ports. You can also program the toggle for one-touch access to your favorite features. You'll have to remove the battery cover to access the microSD card slot, but that's understandable in a water-resistant phone.

Go ahead and give the XP1300 Core a dunking.

Sonim makes lots of promises about the XP1300's durability. It's certified to military specifications for salt, fog, humidity, transport shock, and thermal shock; you can drop it on a concrete floor from 6.56 feet (2 meters); it can tolerate temperatures between minus 4 degrees and 131 degrees Fahrenheit (minus 20 degrees and 55 degrees Celsius); you can submerge it in 6.56 feet of water for half an hour; you can cover it in oil; and it can endure pressure of 1,000 pounds per square inch. We subjected it to every test we performed on the XP3, including dropping it on a hard surface, throwing it down the stairs, putting it in a freezer, and stomping the heck out of it with a boot.

As mentioned, we also put the XP1300 Core through a couple of tests that Sonim prepared for us. First off, we tried calling an XP1300 Core that the company had encased in a concrete block. Though we had to listen closely, we could hear it ringing. Then, after we threw the block on the ground to free the phone, we were able to place another call. Sure, the handset was covered in concrete dust and bits--cleaning off that debris wasn't easy--but it was otherwise unharmed.

For your own look at the tests, check out our Sonim XP1300 First Look video.

The next test was even more gruesome. Using dry ice, we lowered the temperature of a bucket of antifreeze to a frigid minus 20 degrees Celsius before giving the phone a quick bath. Here again, it kept on ticking even if it wasn't entirely unscathed. Though the display continued to shine and the keys registered our commands, the phone's ring volume was much lower immediately after we fished it out of the antifreeze. Sonim said it was a natural effect of extreme temperatures and that the ring volume would return to normal later. Indeed, when we tried it again after some time, the volume was louder.

Keep in mind that we're not guaranteeing that the XP1300 is completely indestructible. Though gadget reviewers, and Sonim itself, have subjected the company's handsets to a variety of torture tests, we've heard from CNET readers who have reported nicks to the armor and scratches on the screen. Also, CNET UK's Charles Kloet was able to break the Sonim XP2 at Mobile World Congress last year. But despite those incidents, the XP1300 Core is stronger than your average phone.

As we said earlier, the XP1300 Core offers everything you need for communication, but not much else. The phone book holds 1,000 contacts with room in each entry for multiple phone numbers, a fax number, a company name, an e-mail address, a birthday, a street address, a URL, and notes. For caller ID, you can pair contacts with a photo and one of 18 polyphonic ringtones.

The XP1300 Core supports text and multimedia messaging. The latter feature is particularly welcome given that we didn't get it on the XP3. Other tools include an alarm clock, a calculator, a unit converter, a world clock, a calendar, a sound recorder, a notepad, a stopwatch, and a text reader.

You'll also find Bluetooth, a file manager, and PC syncing. POP3 and IMAP4 e-mail support are present as well, though the interface is pretty clunky. The XP1300 Core lacks a camera, but it does offer an FM radio and a generic music player that supports MP3, WAV, and AAC files.

The Sonim has an Opera Mini browser. Features include bookmarks, stored pages, and a record of your browsing history. The handset doesn't come with any games or applications, though it supports Java.

We tested the quad-band (GSM 850/900/1800/1900) Sonim XP1300 world phone in San Francisco using T-Mobile service. Call quality was good on some fronts, but not so great on others. We'll start with the high points first.

Placing a call was rarely a problem, and we enjoyed a strong signal once we were connected. T-Mobile's network wasn't so reliable in underground transit stations, but the places we couldn't get a signal were few. Also, we never encountered a dropped call or a failed connection. Audio clarity also was good. Our friends sounded natural, and we didn't notice any static or interference. And on their end, callers said we sounded fine. They could tell that we were using a cell phone, but there weren't any major complaints.

On the downside, however, we found the call volume to be much too low: we had to strain to hear if we were talking in a noisy place. Even when using the phone in a quiet room, we still had to have the volume turned up and hold the phone close to our ear. Sonim says the XP1300 Core has an omnidirectional microphone with noise cancellation, and to its credit the phone did a good job of cutting background noise on either end. But even with that feature, it just wasn't loud enough.

Fortunately, the speakerphone offered more power. The speaker sits on the phone's rear face, but you can hear adequately even when the phone is resting on a table. Speakerphone calls were satisfying to our callers and to us, and we had no difficulties with automated calling systems.

The Sonim XP1300 Core has a rated battery life of 18 hours of talk time and 33 days of standby time. It had a talk time of 10 hours and 3 minute in our tests. According to FCC radiation tests, the XP1300 Core has a digital SAR of 0.601 watt per kilogram.


Sonim XP1300 Core

Score Breakdown

Design 7Features 7Performance 7