I always thought that having too little “octave spread” - i.e., the tendency of the whistle to be too flat in the second octave and too sharp in the first octave - was an inherent problem with cylindrical bore whistles, particularly larger bore ones. I assumed this was the case because it was true of every cylindrical whistle I own, to varying degrees.
I just purchased a whistle made by Colin Goldie. It’s cylindrical, but it has (if anything) the OPPOSITE problem of having toot MUCH octave spread. The second octave is sharper than the first. So apparently, my assumption was completely wrong. Cylindrical whistles, even large bore ones, don’t need to have too little octave spread. They can even have too much octave spread. Which makes me wonder why I’ve never encountered one that has NO octave spread at all. (EDIT: after getting more used to my Goldie whistle, I’m wobbling back and forth over whether the octave spread is too great or not).
What gives? How do you change octave spread from whistle to whistle? Does it have to do with the head design, or something else? And why does this seem to be such a pervasive problem with so many whistles? Why can’t designers get this right?
Also, sometimes how you tune the whistle can affect the spread, it seems. My cylindrical whistles seem to have greater octave spread the further I tune them in, making them more in-tune the when it’s cold and I have to push them all the way in to get to 440 tuning. But on my Morneaux (which is conical), how you tune the whistle doesn’t seem to affect octave spread very much. There isn’t any significant octave spread no matter how you tune it.