In Search of the Optimum Bore

[hans]

@Tunborough

[Thread revival]

Turns out, there is no optimum bore.

A whistle is balanced when performance at the top end is the same as at the bottom end, and it looks like the Q factor is a great measure of that balance. A wide bore favours the Q factor at the bottom end, and a narrow bore favours the Q factor at the top end. But the length of the window, between the windway exit and the blade, also matters. A longer window favours the Q factor at the bottom end, and a shorter window favours the Q factor at the top end. There are probably limits at the extremes, but you can have balanced whistles with wide bores and long windows, or narrow bores and short windows. Further investigation is in order of what the trade-offs are.

Nice to see this old thread revived! Happy New Year to you all! I quite agree to your observations, and thank you for adding the matter of relative window length. I think the geometry of the window is a fairly subjective matter for a whistle maker, and that explains the great variety of geometries amongst makers. It is subjective, because it is a matter of choice of tone and voicing.

I see that the image I posted a few posts up is no longer working, so I post this again with corrected links. This corresponds to a scaling factor of doubling the diameter every 14.4 semitones:

https://music.bracker.uk/Music/Searching-For-The-Optimal-Whistle-Bore.html

@stringbed

Optimum for what and for whom?

My search was for the optimum bore of a whistle, for anyone. The “optimum” being searched as some objective measure.

Personally, very subjectively, I favour most of the time to play whistles with a a narrower bore than what I came to think of “optimum bore” (represented by the red line in the graph), a narrower bore lying in the lighter shaded zone to the left of the red line. And personally, very subjectively, I favour whistles with a window geometry of double the width to the length. I am not advocating this as the answer. I like playing my narrower whistles, because they play a little sweeter and a bit quieter, just great for my living room and solo playing. For ensemble playing, and outdoors, I find a whistle with a more “optimum” bore more suitable.