The back of the S315i houses all controls and features. There's a DC input for the included power adapter as well as a line-in jack that allows you to connect an iPod Shuffle or any non-iPod audio source, though you'll have to provide your own stereo patch cable. Two volume buttons--"up" curved out and "down" dented in for blind control--are housed on the right side, while a power switch sits just above the kickstand. The switch has three settings: off, on, and power-save. When the unit is in power-save mode, it offers up to 20 hours of playback off of the battery, whereas standard mode will provide about 10 hours. A single LED beneath the front speaker grille indicates battery level: green glows when you have more than 40-percent power, orange lights up for 5-to-40 percent, and red indicates less than 5 percent.
The main problem with the Logitech S315i's power-saving mode is that it noticeably decreases audio quality. When we switched the unit into this mode during testing, music sounded thin and weak, with little low-end response. It was barely tolerable. The good news is that the speakers actually sound quite good when running off of wall power or when in standard battery mode. Music comes through clear and open, with no background hiss or distortion, and there is some bass, though not as much as we'd like. Also, while high-end detail is decent, we think the S315i could stand a little more warmth in the mids. Overall, however, we're pleased with the audio response offered by the unit. It's not for audiophiles, but will satisfy the average listener looking to fill a hotel room with tunes. Oh, and it gets good and loud.
