The ROADIE Speaker System uses distributed mode technology which delivers enhanced sound by amplifying its "vibration" off of any flat surface. Designed as a portable speaker for travelers, Roadie works with a variety of sources such as; iPads, iPods, MP3 Players, Smartphones, laptops, portable DVD players, and even features a built-in microphone for VoIP calls. The EVS-5000 features an upward facing tweeter to dramatically increase high frequency reproduction.