This is extremely worthwhile reading for the description of the measuring instrumentation alone. The conclusions based on the experimental data — all expressed in terms of air pressure — will otherwise be no surprise to anyone here. Digital manometers normally permit pressure measurement at two points. On a whistle, the oral cavity is the obvious and accessible one, and the point of comparison would be somewhere inside the bore. The article indicates where that might usefully be, but getting there to measure it is invasive.david_h wrote: I can’t find it now, but I did find this: https://hal.science/hal-00964988 which seems to be research in the general area your folks are discussing. There is a section headed “Pressure controlled artificial mouth”.
The tuners and voicers at Moeck had access to a blowing machine that was essentially what we’ve been talking about designing here. The air feed was set volumetrically and the air pressure was measured at the entrance to the windway. I never saw or heard of anyone using it the entire time I was there. We also all had water-column manometers at our workbenches and used them for such things as calibrating differences between our individual blowing pressures and logging what we did when custom tuning for VIP clients.
trill wrote: 4) One question I have is what role the human anatomy (mouth cavity, throat, lung volume) have on the “total acoustic field”.
I studied the recorder with Bernard Krainis for several years. One of the techniques that he taught — labeling it as counterintuitive but effective — was how to maximize and vary the size and shape of the oral cavity. He said he based it on watching the way Frans Brüggen played and confirmed in discussion with him, that Frans was consciously harnessing the effect. A quick check a few mins ago showed that the pressure in the cavity drops as it is enlarged. The effect on tone quality is perceptible without any shift in pitch, which I assume means an instinctive increase in air flow. There was no immediate indication of any of this making a diff when shifting modes of vibration but I’ll spend more time with that.Tunborough wrote:That we don’t know yet. There is something happening, because skilled recorder players have more control over frequencies around the register shift than novices.
An automated blowing device may be useful for measuring the steady-state behavior of a whistle. However, it would also have to emulate the initial transients of notes bumped into different registers as done by a reasonably skilled actual player. Repeating what I still feel to be a pivotal question — given that so much of the available data is quantified in terms of pressure, and that any one of us can measure that aspect of their own playing, what purpose is there in shifting to volumetric data? Terry’s chronicle of his on-going efforts is informative and fascinating, and it is easy enough to understand the L/min measurements in relative terms. But it would sure be nice to be able to compare them in a more absolute sense, for example, to the workshop literature about voicing organ pipes.Tunborough wrote:What I want to do is measure the output frequency of the whistle as the flow is varied. What’s the frequency at the lowest flow at which a note just speaks? What’s the highest frequency just before a note jumps to the next register? What’s the lowest frequency in the second register before the note drops down to the first register? How does the frequency vary with flow between these extremes? With this information, we can design a whistle that stays in tune with a regular increase in breath flow as we go up the scale.