Abstract
A loudspeaker system (50) has a front loudspeaker enclosure (10) having at least one front loudspeaker (20) and a rear loudspeaker enclosure (30) having at least one second loudspeaker (40). The front loudspeaker enclosure (10) is in the form of a horn-loaded enclosure. The rear loudspeaker enclosure (30) is in the form of a vented high-pass enclosure.
Claims
1. A loudspeaker system for obtaining a higher acoustic output and increasing directional output character of the loudspeaker system, the loudspeaker system comprising: a front loudspeaker enclosure having at least one front loudspeaker; the front loudspeaker enclosure having a closed rear wall; and a rear loudspeaker enclosure arranged at the rear wall of the front loudspeaker enclosure, the rear loudspeaker enclosure having at least one loudspeaker, wherein in loudspeaker system the front loudspeaker enclosure is in the form of a horn-loaded enclosure and the rear loudspeaker enclosure is a single chamber vented high-pass enclosure having at least one vent.
2. A loudspeaker system according to claim 1, wherein impulse and phase responses of the sound source formed by each of the front loudspeaker enclosure and the rear loudspeaker essentially match.
3. A loudspeaker system according to claim 1, wherein the front loudspeaker and the second loudspeaker are operated by the same drive signal.
4. A loudspeaker system according to claim 2, wherein the front loudspeaker and the second loudspeaker are operated by the same drive signal.
5. A loudspeaker system according to claim 1, wherein said at least one vent in the second loudspeaker enclosure is located in a side wall of the loudspeaker system.
6. A loudspeaker system according to claim 1, wherein said at least one second loudspeaker in the rear loudspeaker enclosure is located in a side wall of the loudspeaker system.
7. A loudspeaker system according to claim 1, wherein there are multiple front loudspeakers in the front loudspeaker enclosure.
8. A loudspeaker system according to claim 1, wherein there are multiple loudspeakers and/or multiple vents in the rear loudspeaker enclosure.
9. A loudspeaker system according to claim 1, wherein the front loudspeaker enclosure and the rear loudspeaker enclosure are separate units which form a loudspeaker system when the enclosures are stacked and/or placed against each other.
10. A loudspeaker system according to claim 1, wherein in the loudspeaker system there are one or more separate front loudspeaker enclosures and one or more separate rear loudspeaker enclosures, which are stacked and/or placed against each other to form one unit.
11. A loudspeaker system according to claim 1, wherein the front loudspeaker and the second loudspeaker are operated by two drive signals and/or two amplifiers.
Description
[0024] The invention is hereby illustrated with reference to the drawings. It is noted that in the drawings, which represent different embodiments of the invention, the same reference characters represent the same part of the loudspeaker system of the invention.
[0025] FIG. 1 illustrates a loudspeaker system according to the prior art, which is a so-called end-fire configuration with two similar loudspeaker enclosures 10 and 30 driven by two amplifiers 11 and 31 and two amplifier channels. The loudspeaker enclosure 10 has a loudspeaker 20 and the loudspeaker enclosure 30 has a loudspeaker 40. The propagation time difference between the enclosures 10 and 30 is compensated by an electronic delay device 12. The propagation time difference is designed to correspond to ¼ of the average wavelength λ produced by the loudspeaker system so that the distance between the loudspeakers 20 and 40 is λ/4.
[0026] FIG. 2 illustrates a loudspeaker system 50 according to the invention. The loudspeaker system 50 includes a horn-loaded front loudspeaker enclosure 10 and a vented rear loudspeaker enclosure 30. The front loudspeaker enclosure 10 has a loudspeaker 20, a horn part 22, and closed rear wall 29. The rear loudspeaker enclosure 30 has a second loudspeaker 40 and a vent 42. The sound wave path from the front loudspeaker 20 to the mouth of the horn part 22 is (a) and the sound wave path from the second loudspeaker 40 to the mouth of the horn part 22 is (b). According to the invention the length of the sound wave path (a) and the sound wave path (b) are relatively the same.
[0027] FIG. 3 illustrates a loudspeaker system 50 according to the invention having a horn-loaded front loudspeaker enclosure 10 having a front loudspeaker 20, a horn part 22, a front chamber 23 and a closed rear wall 29. The rear loudspeaker enclosure 30 has a second loudspeaker 40 and a vent 42. According to the invention the horn part 22 is formed as a labyrinth so that the length (a) of the sound wave path from the front loudspeaker 20 to the mouth of the horn part 22 is essentially equal to the length (b) of sound wave path from the second loudspeaker 40 to the mouth of the horn part 22. If the both sound wave paths (a) and (b) are about 2 m, they both equal ¼ of the 8 m sound wave corresponding to the sound frequency of 37 Hz.
[0028] In the loudspeaker system of FIG. 3 the sound wave from the front loudspeaker 20 and the sound wave from the second loudspeaker 40 are summed at the mouth of the horn part 22. The summing of the waves obtains a considerably higher acoustic output of the bass frequency area in front of the speaker system because the summed sound waves have the same phase.
[0029] In the loudspeaker system of FIG. 3 the sound wave from the front loudspeaker 20 travels first 2 m to the mouth of the horn part 22 and then also further another 2 m to the rear loudspeaker 40. So the sound wave has travelled all together a distance of 4 m, which corresponds ½ of the 8 m sound wave corresponding the sound frequency of 37 Hz. When the sound wave from the front loudspeaker 20 and the sound wave from the rear loudspeaker 40 are summed at the point close to the rear loudspeaker 40 they are 180° out of phase causing sound cancellation of the sound wave of the rear loudspeaker and increasing the directional radiating character of the front loudspeaker in the bass frequency area.
[0030] FIG. 4 illustrates a loudspeaker system 50 having a horn-loaded front loudspeaker enclosure 10 and a rear loudspeaker enclosure 30. The enclosures 10 and 30 are divided into two separate units, which can be stacked or placed against each other and locked together to form a combined loudspeaker system 50. However the enclosures 10 and 30 can also be divided into two separate units for easier transporting. The sound wave path from the front loudspeaker 20 to the mouth of the horn part 22 is (a) and the sound wave path from the second loudspeaker 40 to the mouth of the horn part 22 is (b).
[0031] FIG. 5 illustrates a loudspeaker system 50 having two front enclosures 10, 10′ and one rear loudspeaker enclosure 30. All the enclosures 10, 10′ and 30 are separate units, which can be stacked or placed against each other during the operation of the loudspeaker system 50. After the operation the enclosures 10, 10′ and 30 can be divided into separate units for easier transporting. This configuration is useful when less attenuation to the rear side of the loudspeaker system 50 is needed. The sound wave path from the front loudspeakers 20 and 20′ to the mouth of the horn parts 22 and 22′ are each (a) and the sound wave path from the second loudspeaker 40 to the mouth of the horn parts 22 and 22′ are (b) and (c). The loudspeaker system 50 of FIG. 5 may not be as effective as the loudspeaker system 50 of FIG. 4 because the lengths of the sound wave paths (b) and (c) are different.
[0032] FIG. 6 illustrates a loudspeaker system 50 having having one front enclosure 10 with a front loudspeaker 20 and two rear loudspeaker enclosures 30, 30′. All the enclosures 10, 30 and 30′ are separate units, which can be stacked or placed against each other during the operation of the loudspeaker system 50. This configuration is useful when more attenuation to the rear side of the loudspeaker system 50 is needed. Both configurations in FIG. 5 and in FIG. 6 require ¾ of the total amplifier power compared to the configuration illustrated in FIG. 3. It is also possible to tune the enclosures to tune the cancellation frequency due to different propagation difference. The sound wave path from the front loudspeaker 20 to the mouth of the horn part 22 is (a) and the sound wave paths from the rear loudspeakers 40 and 40′ to the mouth of the horn part 22 are (b) and (c). The loudspeaker system 50 of FIG. 6 may not be as effective as the loudspeaker system 50 of FIG. 4 because the lengths of the sound wave paths (b) and (c) are different.
[0033] FIG. 7 illustrates a loudspeaker system 50 having having a front enclosure 10 with one front loudspeaker 20 and a rear loudspeaker enclosure 30 having two second loudspeakers 40, 40′ and one vent 42. The second loudspeakers 40, 40′ are placed into the side walls of the rear loudspeaker enclosure 30 and faced to the sides of the loudspeaker system 50. One vent 42 is placed in the middle of the back wall for maximum distance from the front side of the loudspeaker system 50. The radiation pattern of the complete sound system can have different characteristics when the places of the loudspeakers 40, 40′ and vent 42 are changed. The sound wave path from the front loudspeaker 20 to the mouth of the horn part 22 is (a) and the sound wave paths from the rear loudspeakers 40 and 40′ to the mouth of the horn part 22 are (b).
[0034] FIG. 8 illustrates a loudspeaker system 50 having having a front enclosure 10 with two front loudspeakers 20, 20′ and a rear loudspeaker enclosure 30 having two second loudspeakers 40, 40′ and two vents 42, 42′. The vents 42, 42′ are placed into both side walls for minimum distance from the front side of the loudspeaker system 50. The sound wave path from the front loudspeakers 20 and 20′ to the mouth of the horn part 22 is (a) and the sound wave paths from the rear loudspeakers 40 and 40′ to the mouth of the horn part 22 is (b).
[0035] FIG. 9 illustrates a loudspeaker system 50 having having two separate front enclosures 10, 10′ and two separate rear loudspeaker enclosures 30, 30′. All the separate enclosures 10, 10′ and 30, 30′ can be stacked or placed against each other and locked together to form a combined loudspeaker system 50. However all the enclosures 10, 10′ and 30, 30′ can also be divided into multiple separate units for easier transporting. Any of these enclosures 10, 10′ and 30, 30′ can also be used as individual bass loudspeaker enclosures in a case when smaller units are needed. The sound wave paths from the front loudspeakers 20 and 20′ to the mouth of the horn part 22 is (a) and the sound wave paths from the rear loudspeakers 40 and 40′ to the mouth of the horn part 22 is (b).
[0036] A loudspeaker system according to the invention comprises a front loudspeaker enclosure having at least one front loudspeaker, the front loudspeaker enclosure having a closed rear wall; and a rear loudspeaker enclosure arranged at the rear wall of the front loudspeaker enclosure, the rear loudspeaker enclosure having at least one second loudspeaker, wherein in the loudspeaker system the front loudspeaker enclosure is in the form of a horn-loaded enclosure and the rear loudspeaker enclosure is a single chamber vented high-pass enclosure.
[0037] The impulse and phase responses of the sound source formed by the front loudspeaker enclosure and the rear loudspeaker essentially match. The front loudspeaker and the second loudspeaker are operated by the same drive signal. The vents in the second loudspeaker enclosure can be located in the side walls of the loudspeaker system. The second loudspeakers in the rear loudspeaker enclosure can be located in the side walls of the loudspeaker system.
[0038] There can be multiple front loudspeakers in the front loudspeaker enclosure and multiple loudspeakers and/or multiple vents in the rear loudspeaker enclosure. The front loudspeaker enclosure and the rear loudspeaker enclosure can be separate units, which form a loudspeaker system when the enclosures are stacked and/or placed against each other. In the loudspeaker system there are one or more separate front loudspeaker enclosure units and one or more separate rear loudspeaker enclosure units, which are stacked and/or placed against each other to form one unit. The front loudspeaker and the second loudspeaker can also be operated by two drive signals and/or two amplifiers.
REFERENCE NUMERALS
[0039] 10 Front loudspeaker enclosure
[0040] 10′ Front loudspeaker enclosure
[0041] 11 Amplifier
[0042] 12 Delay device
[0043] 20 Front loudspeaker
[0044] 20′ Front loudspeaker
[0045] 22 Horn part
[0046] 23 Front chamber
[0047] 29 Closed rear wall
[0048] 30 Rear loudspeaker enclosure
[0049] 30′ Rear loudspeaker enclosure
[0050] 31 Amplifier
[0051] 40 Second loudspeaker
[0052] 40′ Second loudspeaker
[0053] 42 Vent
[0054] 42′ Vent
[0055] 50 Loudspeaker system
