Secondhand As New dbx Dual 31band Graphic Equaliser - Part # DBX231SV-AUdbx Dual 31 band Graphic EQ. Item No. DBX231SV AU, DBX231S. Preloved, as new, dbx dual 31 band graphic equaliser unit. This item was used for approximately 3 months for a band that I accepted a mixing job with but subsequently split up. It would have done no more than 10 gigs. Description: Exceptional sound and rugged reliability When the pros need an EQ, they turn to dbx. With a proven track record that spans four decades, dbx EQs are the industry