The subcontrabass flutes are members of the Western concert flute family. Built in two sizes, the instrument in G or F, also known as the double contra-alto flute, has 4.6 to 4.9 metres (15 to 16 ft) of tubing, while the larger instrument in C, also known as the double contrabass flute or octobass flute, has tubing 5.5 metres (18 ft) long, and is the second largest instrument of the family after the hyperbass flute. (...) The subcontrabass flutes are mainly used as the lower voices in large flute choirs.

(Wikipedia, 28.01.2026)