The most basic type of equalization is the bass control on the old home audio equipment to control low frequencies and the treble control to adjust high frequencies. Since there are only two controls, the adjustment is for a fairly wide range of frequencies. In this extension, however, you can adjust a wide set of frequency ranges (60, 170, 310, 600, 1K, 3K, 6K, 12K, 14K, 16K) similar to the well-known VLC player.