Closed tube
Encyclopedia
In the field of acoustics
, a tone is created by the periodic vibrations of air applied to a resonator. There are several ways in music to create such vibrations. One of these is to use a closed tube and to blow across the end. This creates a Bernoulli, or "siphon", effect just below the open end or embouchure
hole. The tube will resonate at a specific frequency, dependent on the length of the tube, the internal diameter and the pressure/velocity of the airstream across the open hole.
A closed tube is a tube which is closed at one end. The tube resonates
at a single fundamental frequency or note but can have overblown notes. These overblown registers can be tuned by using different degrees of conical taper. A closed tube resonates at the same fundamental frequency as an open tube
twice its length or one fourth of the keynote frequency wavelength. In a closed tube, a node
, or point of no vibration, always appears at the closed end and an antinode, or point greatest vibration at the Phi
point (length X 0.618) near the open end (Sometimes called "nodes and waves" to avoid confusion).
By overblowing
a cylindrical closed tube, a note is obtained that is an approximate twelfth above the fundamental note of the tube. This is sometimes described as a fifth above the octave
of the fundamental note. For example, if the fundamental note of a closed pipe is c1, then overblowing
the pipe gives g2, which is a twelfth above c1. Alternatively we can say that g2 is a fifth above c2—the octave above c1. Adjusting the taper of this cylinder for a decreasing cone can tune the second harmonic or overblown note close to the octave position or 8th. (ref: Horns,Strings and Harmony, by Arthur H. Benade.) Opening a small "speaker hole" at the Phi
point, or shared "wave/node" position will cancel the fundamental frequency and force the tube to resonate at a 12th above the fundamental. This technique is used in a Recorder
by pinching open the dorsal thumb hole. Moving this small hole upwards, closer to the voicing will make it an "Echo Hole" (Dolmetsch Recorder Modification) that will give a precise half note above the fundamental when opened. Note: Slight size or diameter adjustment is needed to zero in on the precise half note frequency.
A closed tube is called a "stopped pipe" in the organ
.
Acoustics
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...
, a tone is created by the periodic vibrations of air applied to a resonator. There are several ways in music to create such vibrations. One of these is to use a closed tube and to blow across the end. This creates a Bernoulli, or "siphon", effect just below the open end or embouchure
Embouchure
The embouchure is the use of facial muscles and the shaping of the lips to the mouthpiece of woodwind instruments or the mouthpiece of the brass instruments.The word is of French origin and is related to the root bouche , 'mouth'....
hole. The tube will resonate at a specific frequency, dependent on the length of the tube, the internal diameter and the pressure/velocity of the airstream across the open hole.
A closed tube is a tube which is closed at one end. The tube resonates
Resonance
In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
at a single fundamental frequency or note but can have overblown notes. These overblown registers can be tuned by using different degrees of conical taper. A closed tube resonates at the same fundamental frequency as an open tube
Open tube
In the field of acoustics, a tone is created by the periodic vibrations of air. There are several ways in music to create such vibrations. One of these is to use a tube and to blow across the end. This creates a note of a given frequency, depending on the length of the tube and the pressure of the...
twice its length or one fourth of the keynote frequency wavelength. In a closed tube, a node
Node (physics)
A node is a point along a standing wave where the wave has minimal amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the...
, or point of no vibration, always appears at the closed end and an antinode, or point greatest vibration at the Phi
Phi
Phi may refer to:In language:*Phi, the Greek letter Φ,φ, the symbol for voiceless bilabial fricativeIn mathematics:*The Golden ratio*Euler's totient function*A statistical measure of association reported with the chi-squared test...
point (length X 0.618) near the open end (Sometimes called "nodes and waves" to avoid confusion).
By overblowing
Overblowing
Overblowing A technique used while playing a wind instrument which, primarily through manipulation of the supplied air , causes the sounded pitch to jump to a higher one...
a cylindrical closed tube, a note is obtained that is an approximate twelfth above the fundamental note of the tube. This is sometimes described as a fifth above the octave
Octave
In music, an octave is the interval between one musical pitch and another with half or double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems"...
of the fundamental note. For example, if the fundamental note of a closed pipe is c1, then overblowing
Overblowing
Overblowing A technique used while playing a wind instrument which, primarily through manipulation of the supplied air , causes the sounded pitch to jump to a higher one...
the pipe gives g2, which is a twelfth above c1. Alternatively we can say that g2 is a fifth above c2—the octave above c1. Adjusting the taper of this cylinder for a decreasing cone can tune the second harmonic or overblown note close to the octave position or 8th. (ref: Horns,Strings and Harmony, by Arthur H. Benade.) Opening a small "speaker hole" at the Phi
Phi
Phi may refer to:In language:*Phi, the Greek letter Φ,φ, the symbol for voiceless bilabial fricativeIn mathematics:*The Golden ratio*Euler's totient function*A statistical measure of association reported with the chi-squared test...
point, or shared "wave/node" position will cancel the fundamental frequency and force the tube to resonate at a 12th above the fundamental. This technique is used in a Recorder
Recorder
The recorder is a woodwind musical instrument of the family known as fipple flutes or internal duct flutes—whistle-like instruments which include the tin whistle. The recorder is end-blown and the mouth of the instrument is constricted by a wooden plug, known as a block or fipple...
by pinching open the dorsal thumb hole. Moving this small hole upwards, closer to the voicing will make it an "Echo Hole" (Dolmetsch Recorder Modification) that will give a precise half note above the fundamental when opened. Note: Slight size or diameter adjustment is needed to zero in on the precise half note frequency.
A closed tube is called a "stopped pipe" in the organ
Organ (music)
The organ , is a keyboard instrument of one or more divisions, each played with its own keyboard operated either with the hands or with the feet. The organ is a relatively old musical instrument in the Western musical tradition, dating from the time of Ctesibius of Alexandria who is credited with...
.
See also
- Panpipes
- Open tubeOpen tubeIn the field of acoustics, a tone is created by the periodic vibrations of air. There are several ways in music to create such vibrations. One of these is to use a tube and to blow across the end. This creates a note of a given frequency, depending on the length of the tube and the pressure of the...
- SoundSoundSound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
- AcousticsAcousticsAcoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...
- Physics of music
- Strings (music)Strings (music)A string is the vibrating element that produces sound in string instruments, such as the guitar, harp, piano, and members of the violin family. Strings are lengths of a flexible material kept under tension so that they may vibrate freely, but controllably. Strings may be "plain"...
- Wind instrumentWind instrumentA wind instrument is a musical instrument that contains some type of resonator , in which a column of air is set into vibration by the player blowing into a mouthpiece set at the end of the resonator. The pitch of the vibration is determined by the length of the tube and by manual modifications of...