The Rio Carbon plays MP3s and WMA (including secure WMAs), as well as Audible files for all of you virtual bookworms. Unlike the larger and more complicated Rio Karma, it does not support OGG or FLAC. The Carbon is also a handy voice-recorder, complete with mic-level meter, that captures audio as WAV files through its decent microphone. It is also an ideal way to store and carry essential data files.
The Carbon's strength is its simplicity--it's the player for those who just want to listen to music. Part of this strength is derived from the clean, mature onscreen interface. The main menu includes: Play Music, Bookmarks, Settings, Voice Recorder, Recordings and Stopwatch (lest we forget to mention, it's a stopwatch, too). Diving into menu folders is an in-and-out affair, but the interface transitions are quick and tidy. Selecting the Play Music category takes you to a wealth of options, including Play All, Album, Artist, Genre, Track, Year, New Music, Playlist, Spoken Word, and Recordings. Menu highlights include a five-band custom EQ, simple voice recording, and a nifty bookmarking feature that not only takes you instantly back to the same place in a song but also remembers the player's settings. In fact, you can easily bookmark songs by pressing and holding the Select button and choosing one of nine bookmark spaces.
There's lots of motion onscreen, with scrolling song info, a track position bar, and time elapsed. It's kind of nice, especially with the soothing backlighting turned on, then slowly fading to off. There's also a View mode that displays bit rate, codec, copyright protection, and size, as well as the always-handy date and time. The Carbon even has a customizable Lock setting, meaning you can program some functions--such as volume--to work even when the software Hold function is on.
Software and drivers aren't an issue. Rio supplies its own much-improved Rio Music Manager, but the Carbon is also compatible with Windows Media Player 10.0 and Apple iTunes, although the latter does require a plug-in. And it works with any of the music services that rely on WMA, such as Napster, MSN Music, Wal-Mart, and others. The Carbon takes advantage of the latest technology to deliver a better user experience. It can autosync with Windows Media Player 10.0 and Rio Music, a useful feature if you have more than 5GB of music. The Carbon series is finally compatible with Windows DRM 10.0 (also known as Janus), which allows the player to store and play back songs downloaded from subscription services such as Napster To Go and Rhapsody To Go. This greatly enhances the appeal of this already tight player.
The Rio Carbon isn't perfect, however--it's missing several features found on larger players. There's no FM tuner, no line-in recording, and no hardware Hold button. The interface has a few quirks too. Most notably, there's no way to create a playlist while on the go, an especially important feature on high-capacity players such as the Carbon. During testing, we also found that, if you're using the jog wheel when selecting menu options, you'll get kicked out of the menu and back into the Player mode--a minor annoyance when you are surfing the menus.One of the Rio Carbon's strongest selling points is its phenomenal battery life. At slightly more than 20 hours, it lasts twice as long as the Apple iPod Mini. The Carbon's lithium-ion battery is charged via USB.
Sound quality also rates up there, with punchy, hiss-free sound. The Carbon could be louder, as we were only able to crank it up using the custom EQ. While the included earbuds are termed high quality, the Carbon deserves to be listened to on bigger headphones. Owners of the first Carbon run should just make sure their headphones do not have the aforementioned metallic ring around the base of the plug, which can result in static (see ). Yes, there is a low-tech fix for this problem. But coming from an otherwise polished player, it's a shame that Rio didn't catch this before the unit went into production. Transfer time over USB 2.0 was an acceptable 2MB per second.