J.S. Bach: Prelude and Fugue in E minor BWV 533

To see how 64' pitch is achievable you need to consider the maths. The bottom C on the pedal board for a 16' pipe sounds approx 32Hz. The 21.1/3' pipe will sound approx 24Hz. The resultant frequency is 56Hz by addition but there is also a resultant by subtraction, and that is 8Hz which is equivalent to 64'. That's the theory, but I must admit I've never been that convinced by the actual audible result!

Resultants DO work!
Did the calculations years ago as a teenager.
I have created a 32' resultant by playing a 16' pedal Bourdon and a fith above. (But that is not a perfect fifth.)( Perfect fiths are best.)
Surprisingly, I do not recall ever creating a 64' resultant by playing a 32' stop and fifth above.
The United State Air Force Academy has a pedal 32' Cornet V
(Wish I knew the stops which make it.)

I prefer the actual pitches because the quint in the resultant adds some unclarity.

Some 32' stops become resultants in the bottom octave.
Instead of a 32' pipe, it is two pipes: 16' and 10-2/3' = 26-2/3 feet. That is only 5-1/3' less than a 32' pipe.
I would think making TWO pipes and air channels to them not much less expensive than ONE 32' pipe.

I have played organs which have plenty of room for a 32' but it becomes a resultant. It was not done because of height clearances.

Originally, 1646, the organ compass extended to the F below the bottom C we are used to and this would have been a 24' pipe. I suspect that when F. C. Schnitger did his resoration around 1725 and added a normal compass pedal and manuals he used the old oversized pipes to create the 22' rank because the metal work was available!

be questo e' uno dei piu belli organi del mondo e unico x la sua completezza e stile urgano invidiato da tutto il mondo quello del duomo di milano

l'organo è quello di san lorenzo ad alkmaar, la foto del duomo di milano in verità non c'entra nulla.

What church is that photo taken in? It's not St. Laurenskerk, is it? At least that one looks different on the photos shown on google...

it is the cathedral of milan

absolutely beautiful pipe organ!

I love the over-all sound, but must agree that the tempo seems irregular and there seem to be hesitations, for what reason, I cannot know. Thank you.