CN210722428U - Ancient egg-shaped, holed wind instrument that diapason surpassed two octaves - Google Patents

Abstract

The utility model discloses an ancient egg-shaped, holed wind instrument with a range of more than two octaves, which comprises a pear-shaped cavity and a mouthpiece, wherein a baffle is arranged in the cavity, the baffle divides the cavity into an upper cavity and a lower cavity, and the center of the baffle is provided with an air vent; the cavity wall of the upper cavity is provided with an upper finger hole group, and the cavity wall of the lower cavity is provided with a lower finger hole group. The utility model provides an ancient egg-shaped, holed wind instrument sound field that prior art exists narrower, tone quality is relatively poor, can not reach the technical problem of super wide sound field, reached the technological effect that an ancient egg-shaped, holed wind instrument has super wide sound field.

Description

Ancient egg-shaped, holed wind instrument that diapason surpassed two octaves

Technical Field

The utility model relates to a national wind instrument technical field, concretely relates to ancient egg-shaped, holed wind instrument that the range exceeds two octaves.

Background

An Xun-holed wind instrument is one of the oldest wind instruments in China and can be widely applied to orchestra, bands, performances, teaching, celebration, personal wind instruments and the like. The timbre is simple and the embrace element is a natural sound and plays an important role in the original artistic history of the world. Originally, Xun was mostly made of stone and bone, and was developed into pottery, and its shape was also varied, such as oblate, mother-son Xun, oval, spherical, fish-shaped, pear-shaped, and the pear-shaped is the most common. An ancient egg-shaped, holed wind instrument is the most traditional system among the ancient egg-shaped, holed wind instrument family, and current an ancient egg-shaped, holed wind instrument is single chamber generally, and 8 holes and 9 holes are many, and the sound sympathetic response is good, blow down well, love the person very much, but single chamber structure leads to its range of sound narrower itself, and tone quality is relatively poor, does not reach super wide range, leads to its expressive force to be limited.

Disclosure of Invention

In order to overcome the above-mentioned defect of prior art, the utility model relates to an ancient egg-shaped, holed wind instrument that the range exceeds two octaves, the utility model provides a problem that an ancient egg-shaped, holed wind instrument range that prior art exists is narrower, tone quality is relatively poor, can't reach super wide range, reached an ancient egg-shaped.

In order to achieve the above purpose, the utility model provides a following technical scheme:

an ancient egg-shaped, holed wind instrument with a range of more than two octaves comprises a pear-shaped cavity and a mouthpiece, wherein a partition plate is arranged in the cavity and divides the cavity into an upper cavity and a lower cavity, and a vent hole is formed in the center of the partition plate; the cavity wall of the upper cavity is provided with an upper finger hole group, and the cavity wall of the lower cavity is provided with a lower finger hole group.

Further, the upper finger hole group comprises a finger hole eight and a finger hole four.

Further, the lower finger hole group comprises a finger hole seven, a finger hole six, a finger hole five, a finger hole three, a finger hole two and a finger hole one;

the lower finger hole group also comprises a finger hole nine and a finger hole ten.

Furthermore, a finger hole seven, a finger hole six, a finger hole five, a finger hole three, a finger hole two, a finger hole one, a finger hole eight and a finger hole are positioned on the front surface of the cavity wall; finger hole nine and finger hole ten are located on the back of the chamber wall.

Furthermore, finger hole seven, finger hole six, finger hole five and finger hole eight are positioned on one side of the front surface of the cavity wall, and finger hole three, finger hole two, finger hole one and finger hole four are positioned on the other side of the front surface of the cavity wall.

Further, the diameter of the first finger hole is 3mm, the diameter of the second finger hole is 5mm, the diameter of the third finger hole is 4mm, the diameters of the fourth finger hole and the eighth finger hole are 9mm, the diameter of the fifth finger hole is 6mm, the diameters of the sixth finger hole and the seventh finger hole are 10mm, and the diameters of the ninth finger hole and the tenth finger hole are 11 mm.

Furthermore, the diameter of the vent hole is 15-18mm.

Furthermore, the volume ratio of the upper cavity to the lower cavity is 4-5: 6-5.

Further, the baffle extends inwards along the radial direction of the cavity, and the thickness of the baffle is 5-7 mm.

Further, the baffle is located at forty-six to forty-nine percent of the height of the cavity.

Compared with the prior art, the utility model has the advantages as follows:

the utility model relates to an ancient egg-shaped, holed wind instrument with a range of more than two octaves, which comprises a pear-shaped cavity 12 and a mouthpiece 11, wherein a baffle 13 is arranged inside the cavity 12, the cavity 12 is divided into an upper cavity 15 and a lower cavity 16 by the baffle 13, and the center of the baffle 13 is provided with an air vent 14; the cavity wall of the upper cavity 15 is provided with an upper finger hole group, and the cavity wall of the lower cavity is provided with a lower finger hole group. Can reach 5 treble and 6 treble, so that the Xun has a range of more than two octaves. In order to realize that a small second-degree tone is overlapped in a tone region connected with a real tone region and a overtone region, the real tone region and the overtone region are both provided with a high tone 3, and the high tone 3 can be achieved by opening a finger hole I, a finger hole II, a finger hole III, a finger hole IV, a finger hole V, a finger hole VI, a finger hole seven, a finger hole eight, a finger hole nine and a finger hole ten during playing; the full-push (full-blocking) ultra-blowing can reach the overtone high pitch 3, so that any skill used by a player in playing can pass through without any obstacle; the technical effect that an ancient egg-shaped, holed wind instrument has an ultra-wide range is achieved.

Drawings

Fig. 1 is a perspective view of the present invention.

Fig. 2 is an airflow dynamic diagram of the present invention.

Fig. 3 is a front view of the present invention.

Fig. 4 is a back view of the present invention.

Reference numerals:

1. the first finger hole, the second finger hole, the third finger hole, the fourth finger hole, the fifth finger hole, the sixth finger hole, the seventh finger hole, the eighth finger hole, the ninth finger hole, the 10 finger hole, the tenth finger hole, the 11 mouthpiece, the 12 cavity, the 13 clapboard, the 14 vent hole, the 15 upper cavity and the 16 lower cavity.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Description of the drawings: it is obvious that the invention mainly provides a concept, all technical features details of which cannot be fully refined, and nothing disclosed is left to the knowledge and height of a person skilled in the art to choose from.

Example 1, described in conjunction with figures 1-4.

An ancient egg-shaped, holed wind instrument with a range of more than two octaves comprises a pear-shaped cavity 12 and a mouthpiece 11, wherein a partition plate 13 is arranged in the cavity 12, the cavity 12 is divided into an upper cavity 15 and a lower cavity 16 by the partition plate 13, and a vent hole 14 is formed in the center of the partition plate 13; and the cavity wall 15 of the upper cavity is provided with eight finger holes 8 and four finger holes 4. The cavity wall of the lower cavity is provided with a finger hole seven 7, a finger hole six 6, a finger hole five 5, a finger hole three 3, a finger hole two 2, a finger hole one 1, a finger hole nine 9 and a finger hole ten 10.

In the embodiment of the application, a partition board is arranged in the Xun, and divides the Xun into an upper cavity and a lower cavity, the partition board is preferably arranged at the upper part of the cavity, and the cavity walls of the upper cavity and the lower cavity are respectively provided with a finger hole eight, a finger hole four, a finger hole seven, a finger hole six, a finger hole five, a finger hole three, a finger hole two, a finger hole one, a finger hole nine and a finger hole ten; the common Xun can be used and played as well as when more than two octaves need to be played, the first finger hole, the second finger hole, the third finger hole, the fifth finger hole, the ninth finger hole and the tenth finger hole are blocked, the fourth finger hole, the sixth finger hole, the seventh finger hole and the eighth finger hole are opened for over-blowing, and the high pitch 5 can be achieved; blocking the first finger hole, the second finger hole, the third finger hole, the fifth finger hole, opening the fourth finger hole, the sixth finger hole, the seventh finger hole, the eighth finger hole and the ninth finger hole, and then blowing by half, so as to reach the high pitch of 6. The range of the Xun exceeds two octaves, the range is widened, and the use occasion is improved.

In order to realize that a small second-degree tone is overlapped in a tone region connected with a real tone region and a overtone region, the real tone region and the overtone region are both provided with a high tone 3, and the high tone 3 can be achieved by opening a finger hole I, a finger hole II, a finger hole III, a finger hole IV, a finger hole V, a finger hole VI, a finger hole seven, a finger hole eight, a finger hole nine and a finger hole ten during playing; the full-push (full-blocking) ultra-blowing can reach the overtone high pitch 3, so that any skill used by a player in playing can pass through without any obstacle.

Example 2, described in connection with figures 1-4.

On the basis of the embodiment 1, further, a finger hole seven 7, a finger hole six 6, a finger hole five 5, a finger hole three 3, a finger hole two 2, a finger hole one 1, a finger hole eight 8 and a finger hole four 4 are positioned on the front surface of the cavity wall 12; finger hole nine 9 and finger hole ten 10 are located on the back of the cavity wall 12. A finger hole seven, a finger hole six, a finger hole five, a finger hole three, a finger hole two, a finger hole one, a finger hole eight and a finger hole four are designed on the front surface of the cavity wall so as to be convenient for holding and using the right hand four fingers and the left hand four fingers; the finger holes nine and ten are designed on the reverse side of the cavity wall so as to be convenient for holding the thumb of the right hand and the thumb of the left hand, and the design ensures that the fingers of the left hand and the right hand just fix the whole Xun, which is beneficial to holding and using the Xun integrally.

Further, a finger hole seven 7, a finger hole six 6, a finger hole five 5 and a finger hole eight 8 are positioned on one side of the front surface of the cavity wall 17, and a finger hole three 3, a finger hole two 2, a finger hole one 1 and a finger hole four 4 are positioned on the other side of the front surface of the cavity wall 17. The seventh finger hole, the sixth finger hole, the fifth finger hole and the eighth finger hole are designed on one side of the front face of the cavity wall to facilitate the holding of the four fingers of the right hand, and the third finger hole, the second finger hole, the first finger hole and the fourth finger hole are designed on the other side of the front face of the cavity wall to facilitate the holding of the four fingers of the left hand. The arrangement makes the hands convenient to use and the range adjustment is good.

Further, the diameter of the first finger hole 1 is 3mm, the diameter of the second finger hole 2 is 5mm, the diameter of the third finger hole 3 is 4mm, the diameters of the fourth finger hole 4 and the eighth finger hole 8 are 9mm, the diameter of the fifth finger hole 5 is 6mm, the diameters of the sixth finger hole 6 and the seventh finger hole 7 are 10mm, and the diameters of the ninth finger hole 9 and the tenth finger hole 10 are 11 mm.

Further, the diameter of the vent hole 14 is 15-18mm.

Furthermore, the volume ratio of the upper cavity 15 to the lower cavity 16 is 4-5: 6-5.

Further, the baffle extends inwards along the radial direction of the cavity, and the thickness of the baffle is 5-7 mm.

Further, the baffle is located at forty-six to forty-nine percent of the height of the cavity.

The invention will be further explained with reference to the accompanying drawings 1-4:

this Xun adopts the most popular 'xi' an method in China. The first river of the Xian fingering wide-range Xun is opened. The xi' an fingering of Xun of this application is: fingers corresponding to the first finger hole, the second finger hole, the third finger hole, the fourth finger hole, the tenth finger hole, the fifth finger hole, the sixth finger hole, the seventh finger hole, the eighth finger hole and the ninth finger hole respectively are a left hand little finger, a left hand ring finger, a left hand middle finger, a left hand index finger, a left hand thumb, a right hand little finger, a right hand ring finger, a right hand middle finger, a right hand index finger and a right hand thumb. The xi 'an fingering generally refers to the left-hand bass, and in order to facilitate the habits of professional players and music colleges and other players playing musical instruments with the right-hand bass, an Xun with the right-hand bass of the xi' an fingering is also made, and the finger holes of the left hand and the right hand on the front and the back are reversed according to the marks of the attached drawing 3 when the finger holes are made.

For the sake of clarity, the following order arrangement and pronunciation rules are listed. (Bass sound for carcass 5)

One bass 5 ten fingers full press (all the finger holes are blocked)

Dibass lift 5-finger hole 1 with half hole

Three bass 6 open finger hole 1

Four bass lift 6 open finger hole 3

Five bass 7 open finger hole 2

Six mediant 1 open finger holes 1, 2

Qizhongsheng 1 open finger holes 2 and 3

2- opening finger hole 1, 2, 3 of eight medians

Nine-middle-sized syllable 2- opening finger hole 2, 3, 5

Ten medians 3 open finger holes 1, 2, 3, 5

Eleven mediant 4-finger opening holes 1, 5 and 6

Twelve-tone rising 4- finger hole 1, 2, 5, 6

5 division of 5-syllables in thirteen- medias finger holes 1, 2, 3, 5, 6

Fourteen-middle-rising 5- finger hole 1, 5, 6, 7

Fifteen-tone 6 finger opening holes 1, 2, 3, 5, 6, 7

Sixteen tone rise 6 open finger holes 5, 6, 7, 9

Seventeen-seven medians 7 open finger holes 1, 2, 3, 5, 6, 7, 9

Eighteen high 1 finger hole 1, 2, 3, 5, 6, 7, 9, 10

Nineteen treble 1 finger hole 1, 2, 3, 5, 6, 7, 8, 9

Twenty high pitch 2 finger holes 1, 2, 3, 5, 6, 7, 8, 9, 10

Twenty-one high tone lift 2 finger hole 1, 2, 3, 4, 5, 6, 7, 8, 9

Twenty-two high pitch 3 finger holes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Twenty-three overtone high pitch 3 full-push (full-blocking) ultra-blowing

Twenty-four high pitch 4-finger hole 8 ultra-blow

Twenty-five high-pitch lift 4-hole-opening finger hole 8, 4-hole-opening half-hole ultra-blowing

Twenty-six high pitch 5 finger opening hole 4, 8 ultra-blow

Twenty-seven high-pitch 5- finger hole 4, 6, 7, 8 ultra-blow

Twenty-eight high pitch 6 open finger holes 4, 6, 7, 8, 9 open half-hole ultra-blow

In order to clearly explain the playing principle of the Xun, the operating principle of the Xun is simply described as follows: when playing Xun, the bass zone is required to be blown weakly, the middle zone is blown flatly, and when playing the high range, the air flow is required to be blown strongly, and when playing the overtone, the double-octave Xun also has higher tone called overtone, and when playing the overtone, the air flow is more urgent called ultra-blowing. The level of the sound blown by the Xun-holed wind Chinese instrument changes according to the area change of the finger opening, the sound is increased when the opening area is increased, and the sound is decreased when the opening area is not increased. When blowing a single-cavity Xun, the mouth of a person blows against the edge of the front mouthpiece of the Xun, at this time, the airflow hits the edge of the front eave to cause violent collision vibration and make a sound, part of the airflow blown to the Xun mouth moves along the outer wall of the Xun, and part of the airflow enters the cavity to push the air in the cavity to rotate into a ball along the inner wall. This rotating mass of air will be elastically vibrated by the compression of the blowing air stream. The rotating air group has a fixed vibration frequency because it is fixed, and the fixed frequency and the sound of the air flow collision vibration of the mouthpiece are instantaneous resonance, i.e. the sound emitted by the mouthpiece is the sound of the exciting resonance of the rotating air mass and the mouthpiece, because the finger hole is not lifted, the finger hole is in the full-blocking state, so the sound is called the sound of Xun. The bigger the head of an Xun, the bigger the volume of the inner cavity, the bigger the air mass formed, the lower the resonance frequency and the lower the sound emitted. When a finger hole of an Xun is opened, the gas of the rotating air mass leaks, the balance is broken, the air mass becomes small after the leakage, and the rotating speed is slightly accelerated to establish new balance. The vibration frequency increases as the air mass becomes smaller, and the sound of an Xun becomes higher. And when a finger hole is opened, the air leakage is increased, the rotating air mass is reduced, the frequency is increased, and the sound is increased. However, the finger holes on the cavity wall have too large area, and the sound cannot be generated when the gas leaks too much into the cavity and can not form a rotating air mass.

The working principle of the Xun is as follows:

referring to the attached drawings 1-4, when the Xun-holed wind instrument is played, airflow entering the cavity of the Xun-holed wind instrument from a mouthpiece is blocked by the middle partition plate at the lower part of the upper cavity, and flows backwards along the partition plate after changing direction, the airflow flowing through the air vent in the middle of the partition plate quickly flows into the lower cavity due to the small pressure of the lower cavity, and flows backwards and downwards to form a rotary air mass after being pushed by newly-entering airflow when flowing through the air vent of the partition plate along the rear lower wall of the cavity and turning to the front wall of the Xun-holed wind instrument upwards and changing direction after colliding with the partition plate. The air flow which flows backwards after the lower part of the upper cavity is changed in direction and passes through two sides of the air vent in the middle of the clapboard flows to the rear cavity, is blocked by the rear cavity, then rotates upwards to the direction of the mouthpiece, and is pressed down by the blown air flow when reaching the mouthpiece. The upper cavity forms a rotary air mass, the two air masses of the upper cavity and the lower cavity rotate independently, and the lower cavity air mass is formed by pressure support of the upper cavity air flow flowing through the vent hole in the middle of the partition plate and flowing downwards, so that the upper cavity air mass and the lower cavity air mass are related to each other and vibrate in a coordinated mode during sound production, and the air mass is regarded as a dumbbell-shaped air mass during middle and low tones.

The volume of the upper cavity of the Xun-shaped holed wind instrument is smaller than that of the lower cavity, the volume ratio of the upper cavity to the lower cavity is 4-5:6-5, namely when the total volume of the Xun-shaped holed wind instrument is 10, the volume ratio of the upper cavity to the lower cavity is 4, and the volume ratio of the upper cavity to the lower cavity can be changed by adjusting the position of the middle partition plate to move up and down. It can be seen from fig. 3 that the Xun-holed wind Chinese instrument has two finger holes, namely finger hole four and finger hole eight, on the cavity wall of the upper cavity, and 8 finger holes, namely finger hole one, finger hole two, finger hole three, finger hole five, finger hole six, finger hole seven, finger hole nine and finger hole ten, on the cavity wall of the lower cavity. From the fingering sequence, it can be seen that the sequence of the finger holes opened in the lower cavity can play the sound from the bass 5 to the treble 1. This includes all midrange and bass regions, just the weak blowing region and the flat blowing region. The cavity under the finger holes is opened from bass to middle tone in sequence, due to air leakage, the air mass gradually becomes smaller, the sound gradually becomes higher, the highest tone is the high tone 1 when 8 finger holes of the lower cavity are all opened (refer to eighteen finger sequence arrangements), the tone is the whole finger holes of the lower cavity, and the tone can also be considered to be emitted by the vent hole in the middle of the partition plate. If the lower half portion of an ancient egg-shaped, holed wind instrument is cut off along the lower part of the partition plate in the attached figure 1, the rest portion is a three-hole small ancient egg-shaped, holed wind instrument, and the middle partition plate forms the bottom of the small ancient egg-shaped, holed wind instrument. The air vent in the middle of the clapboard is a hole which is downwards opened by the Xun, and two finger holes, namely a finger hole eight and a finger hole four, are arranged. When playing bass zone, the finger hole four and the finger hole eight do not need to be opened, the downward hole of the small Xun meets the requirement of high-pitched sound production when the lower cavity is opened with 8 finger holes, so that the sound produced by the downward air vent of the small Xun is controlled by the downward air vent of the lower cavity, which is all opened by the 8 finger holes.

When blowing high pitch, it is forced to blow, the air flow is very fast, the air mass of upper cavity body is very fast rotated, because the area of air vent is very small, the diameter of air vent is 15-18mm, according to the diameter of air vent with 16mm, its area is only 2 square centimeters, and the baffle is calculated with diameter 60cm, the area is 28 square centimeters, fourteen times of the area of air vent, so when blowing strongly, the upper cavity has formed an independent small Xun-shaped wind instrument, the volume of this small Xun-shaped wind instrument is only 2/5 multipoint of the whole Xun, so it can emit the sound higher than the highest sound emitted by the whole Xun-shaped wind instrument. While this Xiaoxun, with the vent hole at the bottom, releases some of the capacity for supporting the sounding with the lower cavity 8 fingerholes fully open, the remaining capacity is sufficient to make the treble reach treble 2, treble 3 when finger hole four and finger hole eight are open.

The overtone is required to be blown, the air flow is much stronger than that of strong blowing when the overtone is blown, the finger holes are all blocked by ten fingers when the overtone is blown, the rapid air flow forms an air mass rotating at a high speed in the upper cavity, the vibration frequency of the air mass is multiplied to generate high-pitch-overtone, and the overtone also follows the rule that the height of the overtone changes along with the change of the area of the opened finger hole. When ten fingers are fully blocked, the overtone generated by the ultra-blowing is called the first overtone, the fourth finger hole and the eighth finger hole of the upper cavity are opened to generate the 2 nd and 3 rd overtones, and the tone pitch of the overtone can be raised by matching with the release of the finger holes of the lower cavity. The height of the middle partition plate, the size of the vent hole and the size of the finger hole on the cavity wall of the upper cavity are adjusted, so that the intonation and the pitch of the overtone can be adjusted.

It can be seen from the fingering arrangement of syllables that there is a treble 3 in both the real and overtone regions, so that there is an overlap of small two-degree tones in the region where the real and overtone regions are connected, making any skill of the player in playing unobstructed. The utility model discloses an ancient egg-shaped, holed wind instrument has filled the preparation technique that an ancient egg-shaped, holed wind instrument does not have super wide range ancient egg-shaped, holed wind instrument. The tone quality and the tone color are unified and beautiful in three sound areas of high pitch, middle pitch and low pitch, and are greatly improved compared with the common traditional Xun. The double-cavity manufacturing technology is used, so that when the whole range of the Xun is 5, the bass 5 can be converted into the treble 6, and the tone quality is improved by more than two octaves (the whole range of the common Xun can be converted into the treble 2 from the bass 5), and the expressive force of the musical instrument is improved.

Claims (10)

1. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, which comprises a pear-shaped cavity and a mouthpiece, and is characterized in that a partition plate is arranged in the cavity, the cavity is divided into an upper cavity and a lower cavity by the partition plate, and a vent hole is formed in the center of the partition plate; the cavity wall of the upper cavity is provided with an upper finger hole group, and the cavity wall of the lower cavity is provided with a lower finger hole group.

2. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 1, wherein said upper finger hole group comprises finger hole eight and finger hole four.

3. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 2, wherein said lower finger hole group comprises finger hole seven, finger hole six, finger hole five, finger hole three, finger hole two, finger hole one; the lower finger hole group also comprises a finger hole nine and a finger hole ten.

4. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 3, wherein the finger hole seven, the finger hole six, the finger hole five, the finger hole three, the finger hole two, the finger hole one, the finger hole eight and the finger hole are positioned at the front of the cavity wall; the finger holes nine and ten are positioned on the back of the cavity wall.

5. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 4, wherein said finger hole seven, finger hole six, finger hole five and finger hole eight are located at one side of the front face of the cavity wall, and finger hole three, finger hole two, finger hole one and finger hole four are located at the other side of the front face of the cavity wall.

6. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 5, wherein said finger hole one diameter is 3mm, finger hole two diameter is 5mm, finger hole three diameter is 4mm, finger hole four and finger hole eight diameter is 9mm, finger hole five diameter is 6mm, finger hole six and finger hole seven diameter is 10mm, finger hole nine and finger hole ten diameter is 11 mm.

7. An ancient, holed wind instrument, having a range of more than two octaves, according to claim 1, wherein said ventilation holes have a diameter of 15-18mm.

8. An ancient egg-shaped, holed wind instrument with a range of more than two octaves, according to claim 1, wherein the volume ratio of the upper cavity to the lower cavity is 4-5: 6-5.

9. An ancient, holed wind instrument, having a range of more than two octaves, according to claim 1, wherein said diaphragm extends radially inwardly of the chamber, said diaphragm having a thickness of 5-7 mm.

10. An ancient, holed wind instrument, having a range of more than two octaves, according to claim 1, wherein said baffle is located forty-six to forty-nine percent of the height of the chamber.

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