>>1410320You have to get the opening, where the air comes out perfect and all corners sharp. Make is small then enlargen it as needed to change the tone. The plug you put into the end must be air tight all around it except for the sliver you cut off the top. Start small with how thick of a sliver you remove. Make sure the plug is pushed all the way to the start of the opening where the air comes out. The plug end inside needs to be perfectly flat. Make sure there's no air escaping anywhere at all other than where the whistle noise will be made.
Check out the top whistle. The bottom just has all the special terms for the parts. The sound changes when you change the "bore" size/length, the "blade overcut" angle, the "block" distance in-out of the bore, the size of the exit hole, and the size of the "duct."
