The speaker also acts as an MP3 player, so there are playback controls, as well. Well, perhaps it would be more accurate to say playback control. One jog button serves to power on the unit, play and pause music, skip forward and backward through tracks, and adjust volume. As such, you may find yourself skipping tracks when you meant to change volume and vice versa. There is no navigation to speak of: you just drag and drop tracks (MP3 and WMA are supported) via Windows Explorer or Mac Finder. There also seems to be no rhyme or reason as to how the songs are played, as a different track starts up every time you power on the device, so we were led to believe the player is on perma-shuffle. We don't really mind this, but it is a bit bothersome that the speaker blasts out at top volume each time you turn it on.
Still, the loudness of the X-Mini Happy is definitely impressive for its size. At top volume, the little guy will literally rattle and shake its way across a surface, and with very little distortion for most songs--an extraordinary feat for a speaker this small. Indeed, the overall performance of the X-Mini Happy made us, well, happy. Audio comes through clear, with nice warmth and richness through the mids. There is a reasonable amount of resonance across the low end, but bass is not as thumping as what you would expect from larger speakers. Again, this isn't really a slight, given the tiny size of the unit. All in all, we have no problem recommending the X-Mini Happy to anyone looking for an ultraportable music system or an extra speaker for traveling.