Are you running the spinny d/w when the whistling happens? Is it dependant on which tack or gybe you're sailing?

I just put on a new type of line for my Tornado spin halyard...it's called Paraloc Pirhana line andi t runs thin (5/32") and seems a bit oval in cross section. I suspect that is due to being fresh off the spool. Anyway, first sail with it we heard a whistiling/humming sound changing pitch with wind stength...but only when spinny was up and on port tack. We think it was the retrieval side of the halyard running up the leeward side of the spinny. This is not loaded of course, so it's weird that it could hum or whistle. I guess it could also be from the section along the mast...since it is more to the starboard (leeward while sailing on port) side the mast and it's highly loaded.

Mike.