(Ger. Superoktave).
As the name of an organ stop, Superoctave denotes the Principal-scaled rank an octave above the so-called Octave (Oktave). The latter was itself an octave above the basic Principal rank of the department concerned. Thus if the Prinzipal is 16' and the Oktave 8', the Superoktave is 4'; or respectively 8', 4' and 2'. Not until German influences became strong in the mid-19th century was the term ever used on English organs in preference to ‘Fifteenth’. In Germany itself, Superoktave as a rank in large organs emerged out of the Mixture only from about 1550, previous 2' ranks being scaled as flutes of various types. As the name of an organ coupler, Superoctave is normally a misnomer, the coupler concerned being an Octave coupler playing notes an octave above, not an octave above the octave.
See Organ stop (Fifteenth).
PETER WILLIAMS