Detailed Product Description High performance 32-bit digital effect process 55 Kinds of DSP Karaoke effects (Hall, Delay ... , Reverb, Echo, Room, Chorus, Tremolo ) +/- 8 steps digital Key-controller for music Music bass, treble, balance controls 3 ... independent frequency and volume controls Separate subwoofer output designed for external active sub-woofer sound box or 3 channels amplifier. ...