square tin whistle finger holes

[c.michael payne]

hi, I'm new on here, first post:

I have built a few pvc tin whistles and noticed, as other have, that it's impossible to tune both high and low octaves evenly; one is always too flat or the other too sharp.

After I noticed that the octaves tuning became even further apart when experimenting with a semicircular (concave) fipple lip shape, rather than straight, I had the idea that following on from this effect, square finger holes might allow the octaves to be tuned more closely together.

Is anyone familiar with square holes (I know they make a square hole flute) or has done any experimentation on this?
or opinions based on physics?

thanks

[Dan Hill]

Square holes should work fine if you have square fingers. That wasn't meant to be facetious (well, maybe just a little.) Square corners tend to increase turbulence, and in wind instruments, square holes and square tubes don't have the same effective area as a round hole or tube with the same actual area. The corners tend to be "wasted" space. Check out Phillipe Bolton's recorder pages in the links section. He points out that hole position has the greatest influence on pitch in the lower register, while hole size makes more difference in the upper register. Moving the holes slightly farther down on the whistle, and slightly larger to produce the same pitch in the first octave can improve the tuning in the second octave. The problem is usually worse in the larger whistles. My high D whistles are sometimes a bit sharp, rather than flat, in the second octave. I'm not sure why.
Cylindrical flutes usually have a tapered head joint to improve upper octave tuning. Doug Tipple's page, also in the links, describes a wedge placed in the head joint that accomplishes the same thing. I have done this with G whistles with good results.
I'm not sure whether the shape of the window contributes to the problem. For some reason, I have better luck with curved windows than with rectangular ones, and I made a G whistle with with a round window that works fine.
In any case, we're all a bunch of experimenters. The only real way to find out is to try square holes.
Let us know what you find out. In the meantime, I'll stick with my drill bits.

[c.michael payne]

yes, drill bits faster. I'll give it a go on E hole on a sacrificial whistle. Il take measurements of d and e before and after modification.
first ill modify to cuircular top and flat base, then totally square.

[Dan Hill]

There's a lot of information in the library section. Look in "winds". Under flutes,whistles, etc., there is an article on Configuring a PVC Irish whistle to get the upper register correct, and a lot of other good stuff. There was more discussion on whistles in the early days of MIMF (the Riverdance effect.)

[c.michael payne]

There's a lot of information in the library section. Look in "winds". Under flutes,whistles, etc., there is an article on Configuring a PVC Irish whistle to get the upper register correct, and a lot of other good stuff. There was more discussion on whistles in the early days of MIMF (the Riverdance effect.)

hi,thanks but couldnt find that, do you have the url?
Configuring a PVC Irish whistle to...

[Dan Hill]

The MIMF library of past discussions is near the bottom of the main index page, but is visible only if you're registered and logged in. I'm not sure if linking directly to it is allowed (and also not sure how to do that.) Once you're in, click on Winds, scroll down to flutes, whistles and globular flutes, and you'll hit the jackpot.
The other stuff I mentioned is in the Links section, and you don't have to be logged in to get there.