Listed only by Irwin, who says: A manual mixture composed of either keen or dull String stops, perhaps in various combinations in order to build up a particular tone, as on an Accompanimental or String Organ.

Viol Mixture IV, Baroque; John Hays Hammond Museum (castle), Gloucester, Massachusetts, USA. This is the only known example of this name.

String Mixture III, Antiphonal; Kotzschmar Memorial Organ, Portland City Hall, Portland, Maine, USA; Austin 1912.

String Mixture V, Antiphonal; Watkins Residence, Winona, Minnesota, USA; Aeolian 1924.

String Mixture V, Chancel Swell; First Congregational Church, Los Angeles, California, USA.