That's tricky isn't it. It requires a consideration of whether the cross sectional area of the bore is being significantly diminished over a significant enough length of bore. A lot of value judgments to be made there.paddler wrote: ↑Fri Dec 16, 2022 1:55 pm Regarding bore profiles of whistles, a lot of whistles employ some kind of head taper which I think of as being analogous to the
parabolic head profile of a Boehm flute. Sometimes this takes the form of plug extensions that protrude into the bore either
side of the window. In other designs the external profile of the head may be compressed into a squared-off profile that also
impacts the bore volume in the head area. I'm not sure if you want to add notes on this kind of thing, but it is probably just
as relevant as the specific bore profile of conical bore whistles.
You can't just use a single value, can you? You'd really need to specify the diameters at top and bottom of the taper, and the distance between them, plus the diameter of any untapered section, such as perhaps above the tuning slide.For the conical bore whistles, you would need to specify where on the bore the diameter is measured, if you are going to use just
a single value. Some of the measurements above seem to be using a measurement at the foot. However, I think the more acoustically
relevant measurement would be at the head, close to the window. I think that contributes more to determining whether a particular
whistle performs like a narrow or wide bore cylindrical model.
If we look at our only tapered whistle data point, it currently tells us:
P.G. Bleazey High D in Mopane, tunable (0.37", 9.3mm at foot; 0.50", 12.8mm at middle joint)
Ideally, for the sake of comparisons, we'd need to know where the head bore meets the tapering section, and the diameter(s) and slope(s) above and below it.
And adding the suggested figure for speaking length, we'd end up with something like:
P.G. Bleazey High D in Mopane, tunable (0.50", 12.8mm x length from blade to the end of the cylindrical section; 0.37", 9.3mm x length from there to foot)
This raises a question. In flutes, the narrow part of the tuning slide always protrudes from the head, entering into the wider section in the barrel. Do whistles follow the same convention, the opposite convention (possibly arguing that, hey, we're tapering downwards here, lets make the slide transition part of the taper), or do they vary? I suspect I've seen both. IE, in some cases, the thinner slide poking out of the head, in other cases, the thinner slide poking out of the body. Whatever, anyone providing us with data on a tapered whistle with tuning slide needs to be alert to where the junction between cylinder and taper lies.
OK. Let's plug on! (As we say in the stopper insertion industry). Hmmm, on that note, can D.I.Y. whistle makers be rightly accused of self-flageolation?Regardless of the level of detail, I think a resource like this would be valuable.