How deep does it go?

After knowing that the PVC pipe flutes are easy to make the next question is which tone would be the lowest that could be reached with commonly used PVC tubes.

With a 2" tube I built a "C3"-flute. The next experiment was using a 3" tube, which gave a "A#2"(116,5Hz). The length is approx. 140cm. That means the organ will easily cover at least 3 octaves.

To calculate the scales, I found a useful calculator in German language:
http://www.arndt-bruenner.de/hausorgel/CalcMens.htm