The ROCKMAN SMART GATE is specifically designed to remove high and low frequency hiss, hum and other noise. When no high frequencies are present in the input signal, the upper half of the frequency spectrum is gradually attenuated by a low pass filter at 6 dB per octave starting at either 1 kHz or 500 Hz (depending on the NOISE BAND CUT switch position). This leaves the fundamental tone and low harmonics on FULL BAND, the gate's high pass filter will attenuate low frequencies at 6 dB per octave (up to 20 dB at 60 Hz).The ROCKMAN SMART GATE will not only minimize hiss and noise from all sorts of signal processors and effects, but will also help remove hum and buzz from guitars with single coil pickups and poor RF shielding. This is no ordinary noise gate. The SMART GATE knows to gate out noise slowly when notes are being held, and quickly when they are stopped short. It will not cut off the ends of notes. The gate's attack time is extremely fast and will not degrade picking transients or harmonic overtones.