That reminds me of a joke:
Q: What’s the classical music version of heavy metal?
A. Six tubas in the same room.
I was at a concert where that joke was mentioned. When all the tubas played together, the sensation was almost physically painful. I can easily believe that an organ such as you mention would have unpleasant effects.
16 Hz is already pretty “heavy” and counts as infrasound. A contrabass tuba in C only goes down to 32 Hz, according to Wikipedia, but the same article also says there are at least five known examples of a subcontrabass tuba There was a Mythbusters episode where they cranked the volume way up on a custom subwoofer which was able to get down to 5 Hz, they say.
Now I am wondering how much you could get away with bending a long organ pipe? Cf the Bb sub-contrabass tuba: