An examination of the resonances in modern flutes with ergonomically angled headjoints

This paper investigates the passive resonance spectra of a modern Boehm flute body outfitted with a variety of transverse and end-blown ergonomic headjoints in an attempt to determine if there is anything intrinsic to the acoustics of these instruments that keeps them from being as good as the same flute with a standard headjoint. With the exception of a commercial U-shaped, recurved headjoint, the ergonomic headjoints examined were all home-built from plastic pipe Tees connected to the flute body by means of a modular jointed neck. Spectra were collected with a pressure-based method that uses a localized sound source placed just outside the flute's embouchure hole to generate forward-going and backward-going pressure waves (with amplitudes P + and P −) inside the flute. Power spectra ( P + + P − 2 vs frequency) are obtained by Fourier analysis of the acoustic pressure recorded by a microphone positioned inside the headjoint. The spectra are modeled with a transfer matrix method that extracts the input impedance from the computed values of P + and P − at the measurement position. Detailed results on tuning and harmonicity provide clues to the differences between these instruments but suggest no fundamental deficiencies in the flutes designed to be ergonomic.