Basis of Design
After countless hours of playing, comparing, and evaluating; after years of applying the best engineering, research and aesthetic principles; I conclude the tapered bore is best. I've played the best antiques and the best contemporary flutes (yes, I've tried the competition). I've also played top-of-the line modern Boehm flutes in precious metals. Still, the tapered bore is best. And by that I mean a bore that is straight (cylindrical) in the head, uniformly tapering in the body, with a different taper near the foot (what I call the tailbore). I've applied this model to all the recent designs of various size with good results of power, response, tone and intonation.
Oh, sure: there's good and bad within each category. I've emulated the Boehm bore, the multi-conical (as measured on several classic flutes), the Bessel (exponential) bores and even the cycloid (while I was a graduate student in math). In each case, the flute did not perform as well as one made with the tapered bore described above (and I've built dozens of designs, evaluating them all).
Now others have written some acoustical "fuzzy logic," for example how the sound wave is compressed, reflected, modulated, genuflected or neo-hypo-trans-defibriglobulated. There is even software to calculate hole positions. I'm no stranger to scientific theory, but the proof of the pudding is in the eating: the flute is not better unless the test drive shows it's better, despite all my fancy talk before the test. And yes, some of my ideas would be called "scientific" by some, "fuzzy" by many, and "hairbrained" by others.
But a good flute is built on many additional details including these: the size of the bore; the exact position where the bore changes; the size and shape of the toneholes; the octave correction at the toneholes; the position of the endstopper; and the shape of the blowhole. I have worked hard on these details alone and in combination to develop what I feel is a flute that makes a player into an artistic performer.