Stereo Tool is a plugin for many users of Winamp. It allows you to handlke and modify your songs. But the greatest innovation is that it reduces by 50% the processor charge. It also improves the sound quality because latency reduces from 1.5 second to 0.1 second. It has a low pass filter which improves sound quality. It still has many features which would be too long to enumerate. Handling is easy enough for the basic functions, but a good audio knowledge is necessary for tweaks.