Listed only by Irwin, who says: A solo Diapason of unusually loud tone and large scale, at 8' on the manuals. Compared to the Diapason Magna, this Diapason is more brilliant with harmonics, although not quite to the point of being a Stentorphone. Its intense and dominating fundamental is accompanied by a whole series of harmonics, which make it a solo stop of prime magnitude. . . . It is not primarily a chorus Diapason, its tone being too brilliant for proper blending with the Octave, Twelfth, etc. The Spanish word sonora means �sonorous, harmonious, loud, or clear�.
Diapason Sonora 8', 5-1/3', 4', 2', Chancel Pedal; Cadet Chapel, United States Military Academy, West Point, New York, USA; M.P. Moller 1911.