Built a high D .. out of 1/2" copper tubing .. wooden fipple… tuned correctly . and noticed that the lower three notes seem weaker than the upper 3 … any suggestions on correcting that?
Thanks,
Jim
Try a TINY bevel on the top edge of the fipple where it comes out of the windway. If that helps, add another TINY bit. If the lowest notes are shaky, you want to let a little more of the air go into the whistle instead of out over the blade.
Also, check the alignment of the top of the fipple with the bottom surface of theblade. In most cases, those should line up. You may have to either lower the top of the fipple, or move the blade up or down. Miniscule changes in this region of the whistle can have major influences on the sound.
What he said… 
Also I have found to be extra careful when sanding down the edge of the fipple… and make sure you try to do it evenly into the windway as much as you can..
Reason being: you will make it so that you’ll have to clear it more often, seeing as how moisture will build it right back up to where it was. Sort of “recreating” the surface you just sanded away.
I probably didn’t explain that very well. Any help with that explanation anyone? 
Take care and enjoy your new whistle. Sounds to me like you’re doing a good job of it so far!
Thanks for the info. I guess I missed that in all the other tweak threads. I just modified the front of the windway on a low D that I made. Now the low end plays much better. In fact now it plays. It was almost nonexistant before. I especially appreciate the explanation of why the bevel improves the low notes. Now if I could enlarge my hands a bit.
Ron
It won’t be able to change this whistle, but look at the 8-hole instructions on the flutomat calculator. Two extra holes below the bell note have the effect of moving the note up the tube so it is more balanced with the rest of the whistle.
Also, if your making copper whistle and you have a tuning coupler on it. Note that some people cut the copper with those tubing cutters that spin around the tube. These cutters cause the tube to cave-in slightly and weakens the sound. It’s better to use a hacksaw or bandsaw, but if you do use tubing cutters, file off the sharp edge on the inside diameter and the whole whistle will sound louder and more stable.
BTW - I have a new tin whistle design program called TWCALC. A Windows Executable.
It is on my experimenters section of my website at:
http://jubileeinstruments.messianic-webhosting.com/experiem.htm
In the left-hand column. It shows the cutoff frequency graph to help you get more consistant sound on each note. It’s for 6 holes only - for the six hole purist out there.
Thanks for the replies .. strange thing happened - an 18 wheel truck ran over the fipple and destroyed it … or it may have been a hammer… either way it will never play again. Will go for a new design tomorrow .. gave up on this one until I get better hard wood for the fipple. Little fibers pointing up when wet does strange things to the sound.
Have learned to appreciate the pro whistle makers … this is a game for those who either have patience or develop it while they are making their first whistle. Either way - I will keep on until I get a whistle that sounds good - wet or dry just to know that I can do it. Have learned a lot about what not to do.
If it was easy … really wouldn’t be any fun .. would it?
Jim