For information on the entire Organ mass:
The first part of the fugue is played on a 16' HW Plenum coupled to the RP Plenum for greater clarity.
Pedal on 32' Untersatz and Plenum 16' including Posune and Trompete 8'
Second part on RP 8' Plenum
Third part as first registration except:
added Trompete 8' RP
Added 8'and 4' reeds to the pedal.
I could not resist pulling the Batalla Trompete 8' in the final chord (sorry)