... -966 Graphic Equalizer, Audio Opal, EQ,High-Pass FilterBrief Instrution:BSS Audio provides the Opal FCS-966 Constant Q Graphic Equalizer ... of graphic EQs uses the Constant Q topology, pioneered by BSS Audio, which means that the filter width is constant whatever ... (3kgs), unpacked AC Power: 115/230V AC, 50/60Hz, 30VA. BSS FCS-966 Graphic Equalizer, Audio Opal, EQ,High-Pass Filter