Gain - Controls input sensitivity level. Treble - +/- 14 dB @ 4 kHz Bass - +/- 17 dB @ 40 Hz High Mid - +/- 14dB @ 800 Hz Low Mid - +/- 15 dB @ 300 Hz Master - Controls output level Engage - toggles between on/bypass (blue LED indicates on) Bright/Deep - toggles through broadband “Deep”, “Bright”, or “Deep + Bright” (blue LED indicates on) Headphone Volume - Controls volume of headphone mix