▁frequencies . ▁An ▁external ▁paramet ric ▁equal izer ▁could ▁also ▁be ▁used ▁to ▁remove ▁unw anted ▁" scr atch y " ▁sounds . ▁ ▁Types ▁ ▁There ▁are ▁many ▁vari eties ▁of ▁E UB s ▁available ▁at ▁present . ▁Some ▁E UB s ▁cannot ▁be ▁used ▁with ▁a ▁bow ▁because ▁of ▁the ▁large ▁radius ▁of ▁the ▁finger board ▁and ▁the ▁flat ness ▁of ▁the ▁bridge . ▁These ▁types ▁are ▁therefore ▁sole ly ▁used ▁for ▁p izz ic ato ▁playing . ▁ ▁Other ▁E UB s ▁have ▁a ▁cur ved ▁bridge ▁which ▁perm its ▁a ▁bow ▁to ▁be ▁used . ▁While ▁E UB s ▁are ▁often ▁four - string ed , ▁ 5 , ▁ 6 , ▁ 7 , ▁and ▁ 8 - string ▁models ▁are ▁available . ▁As ▁well , ▁solid , ▁h ollow ▁and ▁' f lo ating ▁top ' ▁configurations ▁are ▁made . ▁While ▁h ollow ▁and ▁' f lo ating ▁top ' ▁models ▁produce ▁a ▁more ▁reson ant ▁tone , ▁they ▁are ▁also ▁more ▁pr one ▁to ▁feedback ; ▁as ▁such , ▁solid - body ▁E UB s ▁may ▁be ▁the ▁best ▁choice ▁for ▁bass ists ▁who ▁play ▁in ▁loud ▁styles , ▁such ▁as ▁jam ▁bands ▁or ▁metal ▁fusion ▁groups . ▁ ▁Play ing ▁techniques ▁ ▁The ▁E UB ▁is ▁played ▁in ▁a ▁similar ▁manner ▁to ▁the ▁double ▁bass . ▁ ▁All ▁E UB s ▁can ▁be ▁played ▁p izz ic ato ▁style . ▁However , ▁only ▁those ▁with ▁a ▁suitable ▁finger board ▁and ▁arch ed ▁bridge ▁radius ▁can