The Sonim XP1 has a 500-contact phone book with room in each entry for five phone numbers, an e-mail address, a street address, and notes. Personalization options are slim here. You can't pair contacts with a photo, and only caller groups can be assigned one of five polyphonic ringtones.
Otherwise, the XP1 concentrates on what a phone should do. It eschews multimedia features in favor of the basics. Inside you'll find text messaging, a vibrate mode, a calendar, an alarm clock, a calculator, a voice recorder, a stopwatch, a countdown timer, and a world clock. There's also push-to-talk support and a speakerphone, which you can activate only after you place a call. The lack of a camera or music player isn't bothersome but we will knock our review model for not including Bluetooth. Sonim says the feature exists on other XP1 models but we couldn't find it on ours.
You can personalize the XP1 with a variety of color themes, wallpaper, and greeting messages. If you want additional ringtones, you can download from the WAP Internet browser. The XP1 does not offer any games or any kind of features aimed at construction workers, outdoorsy types, or extreme sports enthusiasts. A small flashlight would be really nice.
We tested the XP1 in San Francisco using T-Mobile service. Call quality was generally satisfactory. The volume level was high, and we enjoyed a clear signal free of static or interference. Voices sounded natural for the most part, though occasionally the audio was slightly harsh. This was especially true with deeper voices but it wasn't enough to sour our experience. As we noted previously, reception will vary without the GSM 850 band, so if possible we recommend testing the XP1 in your home area before buying.
On their end, callers said we sounded fine, though a few of our friends said the phone picked up a fair amount of background noise. On the other hand, automated calling systems could understand us in relatively noisy conditions. Speakerphone calls were decent. The speaker on the rear face has good output, though voices sounded garbled at times.
Sonim hasn't released battery life ratings, but our tests reveal a talk time of 7 hours and 48 minutes. The Sonim XP1 has a digital