BEHRINGER FBQ3102HD Professional 31-band stereo graphic equalizer for live and studio applications Revolutionary FBQ Feedback Detection system instantly reveals critical frequencies and can also be used as audio analyzer Ultra-low noise 4580 operational amplifiers for highest signal integrity Dedicated mono subwoofer output with adjustable crossover frequency Additional sweepable high and low-cut filters for each channel remove unwanted frequencies, e.g. floor rumble, hiss etc.