fc=c2πAhb⋅Ab⋅tef sub c equals the fraction with numerator c and denominator 2 pi end-fraction the square root of the fraction with numerator cap A sub h and denominator b center dot cap A sub b center dot t sub e end-fraction end-root = speed of sound in air Ahcap A sub h = cross-sectional area of the tonehole Abcap A sub b = cross-sectional area of the main bore = half the distance between adjacent toneholes (spacing) = effective height/thickness of the tonehole chimney
However, the instrument does not act exactly as if it were cut off cleanly at the open hole. The air inside the tonehole itself has mass and offers resistance. This creates an "end correction," meaning the wave actually travels slightly past the center of the tonehole before reflecting. Acoustic Compliance and Inertance
This explains why a clarinet overblows a 12th (triple the frequency), while a flute overblows an octave. Acoustic Compliance and Inertance This explains why a
A series of open toneholes creates what is known as a . This lattice acts as a high-pass filter.
dictates the available harmonic series and native tonal color. dictates the available harmonic series and native tonal
Opening a tonehole creates an acoustic boundary. It allows the standing wave to escape to the outside air earlier than it would at the bell. This shortens the vibrating air column and raises the pitch. The Open Hole Lattice
These tubes continuously widen from the mouthpiece to the bell, like the saxophone, oboe, or bassoon. Even though they are closed at the narrow mouthpiece end, their expanding shape allows them to support a full harmonic series (both even and odd) and overblow at the octave. This produces a rich, complex, and warm tone. 2. Understanding Toneholes: The Basics This produces a rich
Air Columns and Toneholes: Principles for Wind Instrument Design