KR900004308B1 - Woofer ducted port speaker enclosure - Google Patents

Abstract

The enclosure for strengthening the intensity of lowpitched sound includes a sound damping material (I) attached on either side walls (84,37) with certain thickness, a speaker (12) having a speaker cone (26) disposed on front panel, a speaker (14) having a frame (120) having a damping material and disposed on upper and lower open sector, sound ducts (16,18) disposed on openings (76,77) having a certain distance from front panel (39), low wall (128), and the upper part of speaker (14).

Description

Aerodynamic Bass Reflective Enclosure

1A or front view of a 2-woofer ducted port speaker enclosure.

FIG. 1B is a side view of a two-woofer ducted port speaker enclosure showing a virtual flow path of air within the enclosure. FIG.

FIG. 2A is a back view of a government speaker of a two-woofer ducted port speaker enclosure showing the location of attenuation material on the top and bottom sectors of the speaker frame. FIG.

FIG. 2B is a rear view of the bottom speaker of a two-woofer ducted port speaker enclosure showing the four sector positions of the speaker frame. FIG.

3A or front view of a 1-woofer ducted port speaker enclosure.

3B is a side view of a 1-woofer ducted port speaker enclosure showing a virtual flow path of air within the enclosure.

4A is a front perspective view of the left port of a two-woofer ducted port speaker enclosure.

4B is a front perspective view of the right port of a two-woofer ducted port speaker enclosure.

5a or front perspective view of the left port of a 1-woofer ducted port speaker incubator.

5B is a front perspective view of the right port of the 1-woofer ducted port speaker enclosure.

FIG. 6A is a plot of loudness versus frequency curve of a 2-woofer ducted port speaker enclosure measured at the bottom 8 inch (20.32 cm) speaker and port, respectively. FIG.

FIG. 6b is a loudness versus frequency curve diagram of a 2-woofer speaker enclosure representing the sum of the curves of FIG.

FIG. 7A is a loudness versus frequency curve plot of a 1-woofer ducted port speaker enclosure measured at 8 inch (20.32 cm) speakers and ports, respectively. FIG.

FIG. 7b is a loudness versus frequency curve diagram of the 1-woofer ducted port speaker enclosure representing the sum of the curves of FIG.

8A is a loudness versus frequency curve diagram of an enclosure of 1-woofer ducted port speakers measured at 6 1/2 inch (16.51 cm) speakers and ports, respectively.

A loudness versus frequency curve diagram of a 1-woofer ducted port speaker enclosure showing the sum of the curves in FIG. 8B or FIG. 8A.

* Explanation of symbols for main parts of the drawings

10,134: cabinet 12,14,136: woofer speaker

16,18,38,140: Acoustic Duct 20,142: Front Panel

26,28,148 Cone 120 Frame

l26: damping material

The present invention relates to a speaker enclosure, and more particularly to a ducted port speaker enclosure.

Sound can be defined as the vibration generated by an object. Each time the object vibrates, the surrounding air is compressed and expanded, and the compression and expansion in the air continues. Compression and expansion are called sound waves, and the pitch is determined by the frequency of vibration and measured in hertz or Hz. The intensity of sound is determined by the amplitude or distance the vibrating object moves when the object vibrates and is measured in decibels or dB. Pitch affects the loudness of sound but is independent of loudness, where loudness is the superficial intensity of the senses received by the brain, and intensity is the amount of energy in the sound waves. Our ears have a dull sensitivity to low pitches, such as the bottom out of pianos with a frequency of 27 Hz and some organ norwood below 15 Hz. Since a sound with 60 dB intensity is louder at a frequency of 1,000 Hz than at 500 Hz, greater intensity is required to produce the same loudness as at high frequencies at low frequencies. Low frequencies from instruments such as tympani or bass guitars are inaudible to normal listening because the strength of the low frequencies from melting or even living is below the range where these vibrations can be audible.

Recording of the gramophone is performed using a microphone that converts sound waves into current, while loudspeakers reduce the current back to sound waves. Loudspeakers must not only regenerate sound waves from electric current, but also provide a means to increase the intensity of low-frequency sounds, where our ears have relatively low sensitivity. Low intensity can be caused by losses that occur during sound reproduction, including recording studios, recordings, turntables, speakers, as well as associated amplifiers, wiring, connectors, and the like.

Sound waves will radiate radially from the sounding body, similar to the ripples on the surface of water generated when a pebble is dropped into a pond. When a wave encounters an obstruction, such as a wall forming a reflective surface, the wave will be reflected and will spread back in a new direction depending on the direction of the reflective surface. In the speaker cabinet, the sound waves will be reflected by the angular walls he encounters, and the reflected waves will also meet the walls that cause them to reflect back, while new waves will be generated by the vibration of the speaker diaphragm. Each time there is a new vibration, the process is repeated until the various elements of the compound sound effectively vortex, setting up stationary waves, resonance effects, and other phenomena that are very difficult to analyze and anticipate. Therefore, although the overall effect can be measured, the reason for this is usually assumed, because it is difficult to examine the complexities of sound waves generated in the cabinet under the nutrition of the vibrating diaphragm. Various disclosures and concepts have been proposed to anticipate the performance of loudspeaker enclosures, but the final analysis found that the decisive factor in whether a special loudspeaker enclosure produces sound at an appropriate intensity over the audible range is the human ear.

Speaker enclosures for accurate low frequency sound are well known in the art and are commonly referred to as bass reflective or potted boxes. Ports are sometimes referred to as ducted ports, which are combinations of acoustic ducts and their associated port openings. The speaker enclosure will include one or more woofer or low frequency range speakers, tweeter or high frequency speakers, and possibly one or more midrange speakers, which will be tuned to the ducted ports. As described by David Hicks, titled "Manufacture of Speaker Enclosures" in Catalog No. 62-2309 of Radio Shack, published by TAB Books, Inc. Several types of ported box designs and structures have been developed from mathematical formulas and curves. For example, the bass performance of a speaker in various cubic potted boxes includes the following definition: driver frequency of fs-free air resonance; Q _TS- Resonance magnification of driver during resonance; And V ^* _S -compliance of the driver mentioned in terms of air volume with the same compliance as the driver, box volume, box resonant frequency and system cut using a chart, pocket calculator or computer from these definitions. The decision on the off frequency is made. For example, a Thiele potted box requires a box volume of 15 cubic feet (424.752 cm ³ ) when fs = 25 Hz; When fs = 40Hz, a volume of five cubic feeds (141.584 cm ³ ) is required. Lower frequencies are obtained by using potted ducts. U.S. Patent No. 3,037,081 describes an acoustic resonator with a woofer and ducted ports, where there are various combinations of specified values and low values of volumetric variables to increase the mechanical resistance of the loudspeaker's diaphragm. . U.S. Patent No. 3,952,159 describes a bass reflective playback system that exhibits compliance established using woofers, tweepers, and ducted ports to achieve low frequency responses.

Rather than based on calculations that do not factor in the human response to the output, it can be easily manufactured by a handcrafter based on experimental determination of various enclosures and ducted port parameters to obtain the required low frequency range of the sound. There is a need for an inexpensive small soffit enclosure. The equations used in the prior art described above generally presuppose extensive assumptions about the behavior of sound waves in an enclosure and use approximations with regard to the actual characteristics of the expected sound output. Except for relatively large and expensive enclosures, complex tuning tuning is usually required to achieve satisfactory results over a wide range of reproduction sounds when designed only on the basis of calculations.

It is an object of the present invention to provide a compact and relatively inexpensive ducted port speaker enclosure.

Another object of the present invention is to provide a ducted port speaker enclosure that determines the low frequency range of reproduction sound and increases the vibration intensity of the low frequency sound.

It is yet another object of the present invention to provide a ducted port speaker enclosure in which the geometrical values, including the size of the enclosure, the position and size of the speaker, and the size and position of the ducted port, are based solely on the dimensions of the speaker. will be.

These and other objects and advantages will become more apparent from the following detailed description of the embodiments with reference to the accompanying drawings.

[2-woofer speaker system]

Match the size of the port cabinet 10, the position of the low pass woofer speaker 12 and the low pass woofer speaker 14, and the size of the acoustic duct 16 and the acoustic duct 18 in FIGS. 1A and 1B. It has been determined experimentally by the inventor to expand the bass portion of the reproduction sound from the cabinet (10). All measurements can be determined in a relatively simple relationship based only on the size of the speaker, as derived from experimental determination by the inventor.

을 더한 합, 즉 1.81r₁의 거리에 그 중심이 존재하도록 위치 된다. 스피커(12,14)사이의 크기 관계는 스피커(12)의 콘 반경 r₁선이 스피커(14)의 콘 반경 r₂와 동일하거나 더 큰 것이 바람직하다. 발명자는 r₂가 r₁의 4/5정도인 것이 바람직하다는 것을 실험적으로 알게 되었다.The loudspeaker 12 is usually mounted on a vertical line below the loudspeaker 14 on the front panel 20, the two loudspeakers being located in the center between the panels 22 and 24 of the two-woofer cabinet 10. The cones 26, 28 of the speakers 12, 14 protrude into the cabinet 10 through respective openings 30, 32 in the panel 20, respectively. The loudspeaker 12 is at a distance twice the cone radius r ₁ , ie 2r ₁ , on the inner wall 35 of the bottom panel 36, and the panel 22 at a cone radius r ₁ from the inner wall 37.

The sum is added, that is, the center is located at a distance of 1.81r ₁ . The size relationship between the speakers 12 and 14 is preferably such that the cone radius r ₁ line of the speaker 12 is equal to or greater than the cone radius r ₂ of the speaker 14. The inventors have found experimentally that r ₂ is preferably about 4/5 of r ₁ .

It should be noted that all sizes of cabinet 10 and acoustic ducts 16, 18 are inner sizes unless otherwise noted.

The speaker 14 is positioned such that its center 38 is at a distance of the sum of r ₂ + 1.8 / 2.9 r ₂ + r ₁ , i.e., (1.62 r ₂ + r _l ) from the center 34 of the speaker 12. do.

Line m ₁ is parallel to the bottom panel 36, and line m ₁ bisects the panel 22 between the bottom panel 36 and the government panel 39. To position line m1 extend line 40 at an angle of -45 ° from horizontal axis 42 at center 38 and allow line 40 to intersect cone 28 at point 44 and then Line 46 extends at center 38 at an angle of + 225 ° from axis 42 and causes line 46 to intersect cone 28 at point 48. Line m ₁ is a straight line passing through points 44 and 48, respectively, and intersects with panels 22 and 24 at points 50 and 52, respectively.

Line n ₁ penetrates the center 34 of speaker 12 and is parallel to line m ₁ . Line n ₁ intersects panels 22 and 24 at points 54 and 56, respectively. Distance E ₁ between line m ₁ and n ₁ is _{(r l + 1.8 / 2.9r 2} + 0.293r 2) is a means that _{E 1 = r 1 + 0.914r 2} .

The length L ₁ of the cabinet 10 is twice the sum of the distance E ₁ + 2r ₁ , that is, L ₁ = 2 (E ₁ + 2r _l ).

The width W ₁ of the cabinet 10 is twice as large as (r ₁ + 1.3 / 1.6r _l ), that is, w ₁ = 3.625r ₁ .

To position line l ₁ along wall 5 extend line 58 at center 38 at an angle of + 135 ° on axis 42 and line 58 at cone 60 at point 60. To intersect). Line l ₁ extends from point 60 to intersection 62 where panels 20, 22, 39 intersect. Similarly, to position line l ₂ along wall 57 extend line 64 at center 38 at an angle of + 450 ° on axis 42 and the line 64 at cone 66. Intersect with (28) and then allow line l ₂ to extend from point 66 to the intersection 68 of panels 20, 24 and 39.

Line q ₁ is the central axis of the acoustic ducts 16 and 18, is parallel to the line m _l. The line q _l is located at a distance E ₂ from the acoustic line m ₁ , where the distance E ₂ is equal to the distance E _l .

The depth D ₁ of the cabinet 10 from wall 70 to wall 72 is six times the depth F of cone 26, ie D ₁ = 6F.

Referring to FIG. 4A, the acoustic duct 16 is attached to the wall 70 and the wall 37 at the port opening 76 in the panel 20, and is hermetically sealed to each other perpendicularly with the wall 37. It consists of the top part 78, the side part 80, and the bottom part 82 which form an acoustic duct. The wall 37 between the top 78 and the bottom 82 forms the fourth side of the acoustic duct. Referring to FIG. 4B, the acoustic duct 18 is attached at the wall 70 and the wall 84 at the port opening 77 in the panel 20, and is hermetically sealed to each other perpendicularly with the wall 84. It consists of the top part 86, the side part 88, and the bottom part 90 which form an acoustic duct. The wall 84 between the top 86 and the bottom 90 forms the fourth side of the acoustic duct.

Each of the basal, side and bottom thicknesses J of the acoustic ducts 16 and 18 are on the order of 1/8 to 3/16 inches (0.3175 to 0.4762 cm). The thickness T of the front panel 20 depends on the installation conditions of the speakers used, and a thickness of 1/2 inch (1.27 cm) is usually preferred for 6 1/2 inch (16.51 cm) speakers, while 8 inch (20.32 cm) is preferred. A speaker thickness of 5/8 to 3/4 inches (1.59-1.905 cm) is preferred. The thickness T of the panel 20 is uniform and depends on the maximum normally required when speakers of different sizes are used. The thickness of the other panels of the cabinet 10 is similar to the thickness of the front panel 20. All the panels are vertically sealed to one another to form a cabinet 10. The panel should be rigid enough to withstand the vibrations of the reproducing sound without bending it.

The height F ₁ , width K _l , and depth R ₁ of the acoustic duct 16 are determined as follows with reference to FIG. 4A.

a. Line q ₁ bisects the height F ₁ extending from the inner wall 92 of the top 78 to the inner wall 94 of the bottom 82. The height F _l measured along the outer wall 96 of the side 80 plus the thickness J of the top portion 78 is the line l at point 98 when line l ₁ protrudes onto the inner surface of the panel 20. Will match ₁ It should be noted that the height F ₁ is the same size as the depth F of the cone 26 in FIG. 1B.

b. The width K ₁ extends from the inner wall 37 of the panel 22 to the inner wall 100 of the side portion 80. The width K ₁ measured along the outer wall 102 of the top 78 plus the thickness J of the side 80 is at point 98 when line l ₁ protrudes onto the surface 70 of the panel 20. Matches the line l ₁

c. The depth R ₁ extends vertically from the point 98 on the inner wall 70 of the panel 20 by a distance of F ₁ +1/2 F ₁ -T. The total depth of the acoustic duct 16 will be the sum of the depth R ₁ plus the thickness T of the front panel 20.

The height F ₂ , width K ₂ , and depth R ₂ of the acoustic duct 18 are determined as follows with reference to FIG. 4B.

a. Line q ₁ bisects height F ₂ extending from inner wall 104 of government portion 86 to inner wall 106 of bottom 90. The height F ₂ measured along the outer wall 108 of the side 88 plus the thickness J of the top 86 is the point 110 when the line 1 ₂ protrudes onto the inner surface 70 of the panel 20. On line l ₂ .

Height F ₂ is the same size as the depth of cone 26 in FIG. 1B; F ₁ = F ₂ .

b. The width K ₂ extends from the inner wall 84 of the panel 24 to the inner wall 112 of the side 88.

The width K ₂ measured along the outer wall 114 of the government 86 plus the thickness J of the side 88 is at point 110 when line l ₂ protrudes onto the surface 70 of panel 20. Will also match line l ₂ ; K ₁ = K ₂ .

c. The depth R ₂ extends vertically from the point 110 on the inner wall 70 of the panel 20 by a distance of F ₂ + 1 / 2F ₂ -T.

The total depth of the acoustic duct 18 will be the sum of the depth R ₂ plus the thickness of the front panel 20; R ₁ = R ₂ .

Damping material I having a thickness of about 1 inch (2.54 cm) is attached along the inner walls 37 and 84 of the side panels 22 and 24, respectively, from the inner walls 35 of the bottom panel 36, respectively. It extends to the outer wall 116 of the acoustic duct 16 and to the outer wall 118 of the acoustic duct 18.

The inventors have experimentally found that the portion of the material I facing the speaker 12 is good to remove a thickness of about 1/2 inch (1.27 cm) to further enhance bass.

The exact height of the removed portion is not critical but is preferably about half the diameter of the speaker extending about the depth of the cabinet 10 about the line n ₁ .

The speaker 14 has a total depth Y which is slightly less than twice the depth F of the speaker cone 26 when r ₂ is about 4/5 of r ₁ .

Referring to FIG. 2A, the speaker 14 has a frame 120, which has the same size in relation to itself as for example Radio Shack speaker model number 40-10006. It has a plurality of open sectors spaced symmetrically.

The loudspeaker 14 is shown here with a top sector 122 and a bottom sector 124 each covered with attenuating material to attenuate sound from the sector without disturbing the vibratory motion of the cone 28.

For example, material 126, such as metal or light plastic, is about 1/16 inch (0.1588 cm) thick.

A conventional midrange speaker (not shown) and tweeter (not shown) are located in front of the front panel 20 in an area surrounded by line q _l , line l ₁ , bottom 128 of government panel 39, and line l ₂ . Can be installed in a suitable opening (not shown) in the box.

A conventional crossover network (not shown) is also surrounded by the front portion 102 of the line L ₁ acoustic duct 16 and the inner wall 37 of the panel 22 directly above the acoustic duct 16. The inner wall of the front panel 20 in the area also surrounded by the line L ₂ , the government 114 of the acoustic duct 18, and the inner wall 84 of the panel 24 directly above the acoustic duct 18. 70 can be installed on.

FIG. 1B, which is a side view of cabinet 10, illustrates the virtual flow of air mass in cabinet 10 due to the presence of acoustic ducts 16 and 18 and the impact of sound generated by speakers 12 and 14. Doing.

It is assumed that the air mass will appear in vortex and vibration states because the flow of air from the speaker 12 is in two directions.

The first direction 69 will be downward along the wall 70, upward along the wall 72 across the wall 35 and then bent toward the acoustic ducts 16, 18.

The second direction 71 is upwardly along the wall 70 and passes over the speaker 14, crosses the wall 128 and downwards along the wall 72 and then bends toward the acoustic ducts 16 and 18, As shown in FIG. 1B, the air mass flows from the first direction 69 in the acoustic ducts 16 and 18.

The bass vibrations generated by the woofer 14 will reinforce the initial vibrations generated by the speaker 12 in the acoustic duct.

Vibrations from sectors 130 and 132 of the uncovered frame 120 may produce deeper bass due to increased pressure and ultimately increased intensity, as described in the test results described below, and the mass of air in the cabinet 10. Because of the greater pressure on it, it will reinforce the movement of the air mass generated by the speaker l2.

As shown in FIG. 2B, the frame 120A of the speaker 12 has an open sector similar to the frame 120 of the actual speaker 14, i.e., the government sector 122A, the bottom sector 124A, the left sector ( 130A) and the right sector 132A.

However, although the frame 120A does not have to be the same as the frame 120 or installed in any particular direction, it is preferable that the installation direction is the same as that of the speaker frame 120 when four sector frames are used.

[1-woofer speaker system]

The procedure for designing a one-woofer speaker system is practically similar to that described for the two-woofer speaker system described above.

3A and 3B, the size of the 1-woofer port cabinet 134, the location of the low pass woofer speaker 136, and the size and location of the acoustic duct 138 and the duct 140 are determined by the cabinet ( 134) was experimentally determined by the inventors to extend the bass range of the reproducer's playback sound.

All measurements can only be determined in a relatively simple relationship based on speaker size.

The speaker 136 is installed on the panel 142 and the panel of the cabinet 134 together with the cone 148 of the speaker 136 protruding into the cabinet 134 through the opening 150 in the panel 142. Located at the center between 144 and 146.

Speaker 136 sums cone radius r and 2 / 3.5r at distance twice the radius r of cone 148 over inner wall 154 of bottom panel 156 and from inner wall 158 of panel 144. It is located so that its center is at a distance of 1.57r.

Line m ₂ is parallel to bottom panel 156 and bisects panel 144 between bottom panel 156 and government panel 160.

Extend the line 162 at the center 152 at an angle of + 45 ° from the horizontal axis n ₂ passing through the center 152 to locate the line m ₂ , and the line 162 at the point 164 with the cone ( 148, extending line 166 at center 152 at an angle of + 135 ° from line n ₂ , and intersecting line 166 with cone 148 at point 168.

Line m ₂ is a straight line that passes through points 164 and 168 and intersects with panels 144 and 146 at points 170 and 172, respectively.

Lines m ₂ and n ₂ are parallel and the distance E ₃ = 0.707r between them.

All sizes of cabinet 134 and acoustic ducts 138, 140 are inward dimensions unless otherwise noted.

The length L ₂ of the cabinet 134 is _{twice that} of (r + r + 0.707r), that is, L ₂ = 5.414r.

The width W ₂ of the cabinet 134 is twice as large as 1.57r, that is, W = 3.14r.

Line l ₃ extends from point 168 along wall 174 of front panel 142 to point 176 at the intersection of panels 142, 144, 160.

Line l ₄ extends along the outer wall 174 of the front panel 142 from point 164 to point 170 at the intersection of the panels 142, 146, 160.

Line q ₂ is the central axis of the acoustic ducts 138, 140 and is parallel to line m ₂ .

Line q ₂ is located at distance E ₄ from line m ₂ , where E ₄ is equal to distance E ₃ .

That is, E ₄ = 0.707r.

The depth D ₂ of the cabinet 134 from the inner wall 180 of the panel 142 to the inner wall 228 of the panel 284 is six times the depth F of the cone 148, ie, D ₂ = 6F.

Referring to FIGS. 5A and 5B, the acoustic duct 138 is in the panel 142 in the port opening 181 in the inner wall 180 of the front panel 142 and in the inner wall 158 of the panel 144. A wall 158 between the government 182 and the bottom 186, all of which are sealed at right angles with the wall 158 to form an acoustic duct that forms the fourth side of the acoustic duct. 182, side portions 184, and bottom portion 186.

The acoustic duct 140 is attached to the inner wall 180 of the front panel 142 and to the inner wall 188 of the panel 146 at the port opening 189 in the front panel 142 and to the government 190. The front portion 190, side 192 and bottom all of which are sealed at right angles with the wall 188 by forming a sound duct between the wall 188 and the bottom 194 forming a fourth side of the sound duct. It is composed of (194).

The thickness J of each of the side, side and bottom of each acoustic duct 138, 140 is on the order of 1/8 to 3/16 inch (0.3175-0.4762 cm).

The panel thickness T of the cabinet 134 is considered to be similar to the panel thickness of the cabinet 10 described above.

All the panels are hermetically sealed together at right angles to form a cabinet 134.

The panel shall be rigid to withstand the vibration force of the reproduced sound without bending.

The height F ₃ along with the inner width K ₃ and depth R ₃ of the acoustic duct 138 is determined as follows with reference to FIG. 5A.

a. Line q ₂ bisects the height F ₃ extending from the inner wall 198 of the government portion 182 to the inner wall 200 of the bottom 186. The sum of the height F ₃ measured along the outer wall 202 of the side 184 and the thickness J of the top 182 is the point 204 when the line l ₃ protrudes onto the inner surface 180 of the panel 142. Will match on line l ₃ .

It should be noted that the height F ₃ is the same size as the depth F of the cone 148 in FIG. 3B.

b. The inner width K ₃ extends from the inner wall 158 of the panel 144 to the inner wall 206 of the side 184.

The sum of the width K ₃ measured along the outer wall 208 of the government portion 182 and the thickness J of the side portion 184 is the point 204 when the line 1 ₃ protrudes onto the inner surface 180 of the panel 142. Will also match line 1 ₃ .

c. The inner depth R ₃ extends at a right angle equal to 4 / 3F ₃ -T from the point 204 on the inner wall 180 of the front panel 142.

The overall depth of the acoustic duct 138 will be the sum of the depth R ₃ and the thickness of the front panel 142, ie 4 / 3F ₃ .

The height F ₄ , width K ₄ , and depth R ₄ of the acoustic duct 140 are determined as follows.

a. Line q ₂ bisects height F ₄ extending from inner wall 210 of government 190 to inner wall 212 of bottom 194. The sum of the height F ₄ measured along the outer wall 214 of the side 192 and the thickness J of the government 190 is at point 216 when line l ₄ protrudes into the inner surface 180 of panel 142. Will match line l4.

The height F _{4 is the} same distance as the depth _{of the} cone 148 (see also FIG. 3B); F ₄ = F ₃ .

b. The width K ₄ extends from the inner wall 188 of the panel 146 to the inner wall 118 of the side 192.

The sum of the width K ₄ measured along the outer wall 220 of the government 190 and the thickness J of the side 192 is at point 216 when line l ₄ protrudes to the inner surface 180 of panel 142. Will also match the line l ₄ ; K ₄ = K ₃ .

c. Depth R ₄ extends perpendicularly at a distance equal to 4 / 3F ₄ -T from point 216 on inner wall 180 of front panel 142.

The total depth of the acoustic duct 140 will be the sum of the depth R ₄ and the thickness of the front panel 142, ie 4 / 3F ₄ ; R ₄ = R ₃ .

The damping material I having a thickness of about 1 inch (2.54 cm) is attached along the inner wall 158 of the panel 144 and the inner wall 188 of the panel 146, and the inner wall of the bottom panel 156. It extends from 154 to the outer wall 222 of the acoustic duct 138 and from the inner wall 154 of the bottom panel 156 to the side wall 224 of the acoustic duct 140.

The inventors have experimentally found that it is desirable to remove a thickness of about 1/2 inch (1 .27 cm) of the portion of material I opposite speaker 136.

The exact height of the removed portion is not critical but is preferably about half the diameter of the speaker 136 extending around the line n ₂ to the depth D ₂ of the cabinet 134.

Front panel 142 in an area surrounded by a conventional midrange speaker (not shown) and tweeter (not shown) with line q ₂ , line l ₃ , inner wall 226 of government 160 and line l ₄ . It may be installed in a suitable opening (not shown) in the inside.

Also in an area where a conventional crossover network (not shown) is surrounded by line l ₃ , side 208 of government 182, and inner wall 158 of panel 144 directly above acoustic duct 138 or Inner wall l80 of front panel 142 in an area surrounded by line l ₄ , wall 220 of government 190, and inner wall 188 of panel 146 directly above acoustic duct 140. It can be installed on.

FIG. 3B, a side view of cabinet 134, illustrates the imaginary flow of air mass within cabinet 134 due to the impact of vibrating sound from speaker 136 and the presence of acoustic ducts 138, 140.

As in the two-woofer speaker cabinet 10 described above, it is assumed that the air mass in the cabinet 134 will appear in vortex and vibration states because the flow of air mass from the speaker 136 is in two directions.

The first direction will be downward along the wall 180, upward along the wall 228 across the wall 154 and then bent towards the acoustic ducts 138, 140.

The second direction 232 upwards along the wall 180 and across the wall 226 and down along the wall 228 and then bends toward the acoustic ducts 138 and 140 to effectively interact with the air mass in the first direction 230. Coupled to effectively combine with the air mass in the first direction 230 to enhance the motion of the air mass in the first direction 230 and to produce deeper bass as shown in the segregation results.

According to the inventor's experiment, the inclination of the edges of the top and bottom of each of the acoustic ducts 16 and 18 in FIG. 1B and the diagram of the acoustic ducts 138 and 140 in FIG. 3B of FIG. 1B shows a slight improvement in the output sound quality. As can be seen, it is not considered important to incline these edges to the disclosure of the present invention.

The manufacture of the two-woofer speaker cabinet 10 or the one-woofer speaker cabinet 134 is relatively simple for a handful or large producer.

All sizes are based on the size of the speakers used. The installation of sound insulation material on the inner wall of the cabinet and the installation of acoustic damping material covering the government and bottom sectors of the government woofer in the two-woofer speaker cabinet 10 in a sealed manner are generally known among skilled workers. .

A convenient opening at the back of the cabinet can easily be provided to have a sealing mating door (not shown) to reach the cabinet when installing the part.

Size E ₁ with respect to manufacturing tolerances will be quite similar to the size of E ₂ less than 10% with respect to the cabinet 10, and the size E ₃ is to be understood that it be fairly similar to the size E ₄ within 10% with respect to the cabinet 134 .

The remaining measurements will be within 10% of each size determined from various relationships without severe degradation of the bass from the cabinet.

All internal connections of the cabinet and each acoustic duct may be sealed with conventional seals, for example caulking.

Each speaker in the cabinet is preferably fitted into an opening that allows for close fitting with each front panel.

Cabinets made in accordance with the present invention will not only be smaller but less expensive, and will provide deeper bass than any other speaker currently on the market except for larger and more expensive speaker enclosures.

6a, 6b, 7a, 7b, 8a and 8b show the relationship between the loudness measured in decibels (dB) along the vertical or longitudinal axis and the frequency measured in hertz (Hz) along the horizontal or abscissa. To illustrate.

6a and 6b are for the cabinet 10, 7a and 7b are for the cabinet 134 when the cabinet (10.134) is equipped with an 8 inch (20.32 cm) speaker, 8a and 8b are for a cabinet 134 with 6 1/2 inch (16.51 cm) speakers.

Measurements were made while maintaining approximately 1 inch (2.54 cm) vertically from the center of the speaker and port measured in the average room.

Since the measurement for the acoustic duct was performed in only one duct opening, the measurement for the acoustic ducts 16 and 18 was only performed for the acoustic duct 16, and the measurement for the acoustic ducts 138 and 140 was only the acoustic duct 138. Only).

As shown in FIGS. 6B, 7B, and 8B, the intensity-frequency relationship of the sound coupled with the acoustic duct and the speaker was obtained by summing each point on the curve in FIGS. 6A, 7A, and 8A.

Reel time analyzer No. 3347, produced by Bruen and Kjaer, Inc. of the Denmaark Kingdom, was used to generate acoustic frequencies and measure the volume of the output sound.

The dashed lines in FIGS. 6A, 7A, and 8A refer to the loudness frequency relationship of sound in each acoustic duct.

The solid line in FIG. 6A is the loudness-frequency relationship of sound in the lower woofer in cabinet 10.

The solid lines in FIGS. 7A and 8A are the loudness-frequency relationship of the sound of the speaker in cabinet 134, respectively.

In operation, the speaker 14 serves to reinforce and enhance the bass from the speaker 12 as measured in the acoustic ducts 16 and 18. It can be seen from FIG. 6A that the bass output to the acoustic ducts 16 and 18 is about -19 dB while the bass output from the speaker 12 is about -28 dB at 20 Hz.

The following were used for the measurement; Speaker 12: 8 inches (20.32 cm), radio model # 40-1006; Speaker (14): 6 1/2 inches (16.51 cm), radio model # 40-1009.

The cabinet 10 has an internal volume of 1.72 cubic feet (48.705 cm ³ ) and is 12 inches (30.48 cm) wide, 9 1/2 inches (24.13 cm) deep and 26 inches (56.04 cm) high. Have

The acoustic duct (16.18) is 2 1/4 inches (5.72 cm) wide, 11/2 inches (3.81 cm) deep, and 1/2 inch (3.81 cm) high.

Similarly, it can be seen from FIG. 7A that the bass output to the acoustic ducts 138 and 140 is about -23 dB while the bass output from the speaker 136 is less than -30 dB at 20 Hz.

The following were used for these measurements; Speaker (136): 8 inches (20.32 cm), radio color model (# 40-1006).

인치(47.625cm)의 높이를 가지고 있다.The cabinet 134 has an internal volume of 1.07 cubic feet (30.299 cm ³ ) and is 11 inches (27.94 cm) wide and 9 inches (22.86 cm) deep.

It has a height of 47.625 cm.

Acoustic ducts 138 and 140 each had a width, depth and height of 1 1/2 inches (3.81 cm).

It can be seen that at 20 Hz in FIG. 8A the bass output to the acoustic ducts 138 and 140 was about -23 dB while the bass output from the speaker 136 was below -30 dB.

인치(39.69cm)의 높이를 가지고 있었다.The cabinet 134 has an internal volume of 0.58 cubic feet (16.424 cm ³ ) and is 9 inches (22.86 cm) wide and 71/2 inches (19.05 cm) deep.

It had a height of 39.69 cm.

인치(3.49cm)이며, 깊이는

인치 (2.86cm)이며, 높이는 11/4인치(3.18cm)이었다.The internal size of the acoustic ducts 138, 140 is wide

Inches (3.49 cm) and the depth is

Inches (2.86 cm) and height 11/4 inches (3.18 cm).

Speaker 136 was a 6 1/2 inch (16.51 cm) radio model # 40-1009.

Although only two embodiments of the invention have been shown and described, it is not to be limited thereby, but only by the appended claims.

Claims (2)

In an enclosure for increasing the intensity of the low frequency range of reproduced sound, a cabinet having both side walls 24 and 22, a front panel 20, a back panel, a government panel 39 and a bottom panel 36 of a set size ) And; A sound damping material (I) of a predetermined size attached to the right side wall 84 and the left side wall 37 in the cabinet; Speaker cones 26 having a set radius size installed on the front panel 20 of the cabinet at a distance set from the inner wall 35 of the bottom panel 36 of the cabinet and from the right and left walls 84, 37. A speaker 12 provided with; At a distance set from the speaker and from the right and left walls 84, 37, there are a plurality of open sectors of similar size spaced symmetrically spaced into the cabinet on the front panel 20, at least one of which is A speaker (14) having a frame (120) having attenuating material (126) in contact with the top or bottom and installed in the top and bottom open sectors; And a predetermined size of government attached to the cabinet at openings 76 and 77 on both sides of the speaker 14 on the front panel 22 of the cabinet and the set distance from the bottom wall 128 of the government panel 39 ( Aerodynamic bass reflective enclosure characterized by consisting of acoustic ducts (16,18) having a bottom portion (82,90), a bottom portion (82,90) and a right portion, a left portion (80,88). In an enclosure for increasing the intensity of the low frequency range of the reproduction sound, a cabinet 134 having both side walls 146 and 144, a front panel 142, a rear panel, a government panel 160, and a bottom panel 156 of a set size; ; An acoustic damping material (I) of a predetermined size attached to the right side wall (188) and the left side wall (158) in the cabinet; A speaker cone 148 having a set radius size installed on the front panel 142 of the cabinet at a distance set from the inner wall 154 of the bottom panel 156 of the cabinet and from the right and left walls 188, 158. One speaker 136; And a set sized government 182,190 attached to the cabinet at openings 181, 189 on both sides of the speaker 136 on the front panel 142 of the cabinet and at a set distance from the bottom wall 226 of the government panel 160. And an acoustic duct (16,18) having a bottom portion (186,194), a right portion, and a left portion (184, 192), respectively.

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