Design
The Samsung SPH-M510 is so flat and smooth that we almost had the urge to skip it across the nearest pond. The rounded edges and lack of raised surfaces certainly make it look like a skipping stone, an effect that's only magnified by the black version of the handset. On the other hand, the pink model certainly screams for attention, as the hue is almost fluorescent. At 3.7 inches long by 2.0 inches wide by 0.64 inch thick, the SPH-M510 isn't the most compact flip phone out there, but it's certainly light at 2.93 ounces. The handset has a comfortable feeling in the hand, but we couldn't help but notice the construction felt the slightest bit flimsy.
The external display is small (just one inch, 96x96 pixels) for the phone's overall size, but it supports 65,000 colors. It also shows all the necessary information including the date, time, signal strength, battery life, and photo caller ID. The camera lens sits right above and you can use the display to take self-portraits. The resolution was rather dim, though (you only can change the contrast), and the camera doesn't come with a flash. A small speaker below the display completes the front flap, though we were hoping for external music controls. The left spine is home to a volume rocker while the right spine holds a camera shutter, the charger/headset jack, and the microSD card slot. Unfortunately, the side buttons are quite thin, but we like that Samsung didn't cram the memory card slot behind the battery.
Inside the phone, you're in for another color change. The lavender hue is a bit striking, especially when compared to the bright-pink outside. The internal display supports 262,000 colors and measures 2.1 inches (176x220 pixels). Like most Samsung screens, it is bright and vibrant, though difficult to see in direct light. You can change the brightness, the dialing font style, the menu font size, and the backlighting time. The menu styles are easy to use and come in two choices.
The SPH-M510's controls ultimately are one of its downfalls. In an effort to keep the phone as thin as possible, Samsung gave the keys no definition, save for a very slight texture change that doesn't alleviate the slippery effect. As a result, we suffered from a few misdials and had a hard time dialing by feel. We imagine that speedy text messengers would need some time to acclimate. On the upside, the keypad buttons are rather large and they have bright backlighting. The navigation array consists of a four-way toggle, two soft keys, the Talk and End/power controls, a dedicated speakerphone/voice commands key and a Back button. The toggle is relatively large and it doubles as a shortcut to four user-defined functions. And for even more one-touch access, the SPH-M510 supports a programmable Favorites menu for oft-used functions.
Features
The 499-contact address book on the SPH-M510 supports five phone numbers, an e-mail address, a Web address, a nickname, and notes. You can save contacts to groups and pair them with a photo and one of 19 polyphonic ringtones for caller ID. Other basics include a vibrate mode, text and multimedia messaging, an alarm clock, a calculator, a calendar, a memo pad, and a world clock. On the higher end, you also get a speakerphone, instant messaging, e-mail, voice commands and dialing, and USB storage. Bluetooth for headsets and file transfers is also on board, though you don't get a stereo profile.
As an EV-DO phone, the SPH-M510 offers full support for Sprint's 3G services. You can connect to Sprint's Power Vision, which includes Sprint TV, movie previews, and programming from channels such as ABC News, MTV Mobile, ESPN, Logo Mobile, Comedy Central, and Nickelodeon. If radio is your thing, you also can stream tunes from Sirius Radio, while mobile podcasts are available from Samsung on a broad range of topics. But wait, there's more. The carrier's PowerView service offers additional shows and downloadable content as well as the On Demand service for access to a host of information that includes news headlines, sports scores, and weather updates personalized for your ZIP code.
The SPH-M510's music player is similar to that on Sprint's other music phones. You can access the Spint Music Store for simultaneous downloads both to your PC and wirelessly to your phone. The music player interface is nothing too fancy. Though you get album art, the features are limited to repeat and shuffle modes and you can't use MP3s as ringtones. The airplane mode turns off the phone's calling functions for listening to music while in flight. Samsung includes a 3.5mm headphone adapter in the box. (It's doesn't actually include headphones; rather, it's just a microphone and the proprietary connection for the SPH-M510.)
Performance
We tested the dual-band, dual-mode (CDMA 800/1900; EV-DO) Samsung SPH-M510 in San Francisco using Sprint service. Call quality was fine on the whole, but we had a few issues. On the upside, we had no problem getting a signal and the volume level was more than adequate, but there was a slight fuzziness to the audio quality. Voices sounded natural enough, but they weren't crystal clear. How bothersome it is will depend on your perception; we suggest you test the phone first. Callers didn't report as many problems. They said they could hear us well most of the time, but they had more difficulty when we were in windy or noisy conditions. Likewise, automated calling systems could understand us only when we were in a quiet room.
Speakerphone quality wasn't spectacular, either. The volume level was rather low on our end, though voices didn't have the muffled effect so common on many speakerphones. Callers could hear us only when we were speaking close to the phone. On the other hand, Bluetooth calls were fine.
Interestingly enough, multimedia performance was actually better than voice calls. Yes, we get that it's a phone first and not primarily a music and video player, but we were quite satisfied with both functions. Video wasn't pixilated or choppy and it handled quick onscreen movements well. Voices matched the speakers' mouths and the audio quality was fine. Also, we never had to pause for rebuffering and videos downloaded quickly with the strong EV-DO connection. Music quality was admirable as well, and we like the speaker on the front face. Songs could sound tinny at higher levels, but that's to be expected. Songs downloaded quickly at just less than 45 seconds.
The Samsung SPH-M510 has a rated battery life of 3.5 hours talk time. Our tests revealed a talk time of 3 hours and 21 minutes. According to FCC radiation tests, the SPH-M510 has a digital SAR rating of 1.26 watts per kilogram.