Mentioned only by Adlung, who cites an example �at Breslau�, and says only that it �must contain a 16', though this is almost unbelievable; yet Praetorius has expressly said it is there.� The suffix bass indicates that it belongs to the pedal, and the term unterchormass indicates 16' pitch (see Chormassprincipal). Perhaps in this case it indicates that the mixture support the 16' harmonic series, and does not itself contain a 16' rank.