The EQ351 single channel 31 band 1/3 octave graphic equalizer features constant Q circuitry with a 3% center frequency accuracy, 20mm center detent sliders, selectable boost/cut range of 6dB or 12dB, active balanced and unbalanced input and output connect-ions, adjustable high pass filter, adjustable low pass filter, variable input level control, clip level indicators, ground lift switch, internal power supply and selectable line voltage switch. A range control switch is provided which allows you to set the maximum boost or cut for each band of equalization to either 6dB or 12dB. The high pass filter rolls off lower frequencies which is useful for decreasing rumble or low frequency hum from a signal. Its range is adjustable from 10Hz to 250Hz. Frequencies below this setting is rolled off, while frequencies above are unaffected. The low pass filter rolls off higher frequencies which is useful for reducing hiss or sibilance from a signal. Its range is adjustable from 3kHz to 40kHz. The rugged, all-steel constructed chassis occupies 1U rack space and is intended for installation in standard 19" equipment racks.