The Boostaroo Revolution is a high definition splitter and amplifier for portable audio, and it can boost your volume by up to 400% without distorting your music. Their patented circuit breaks apart compressed audio signals into three seperate audio channels. This effect not only produces a highly defined sound, but creates imaged surround sound as well. The Revolution works with portable DVD players, MP3 and CD players, satellite radios, PC’s, Laptops, and FM transmitters. $60 at Boostaroo.