Loudspeaker

Abstract

The present invention describes a loudspeaker comprising a housing and a plurality of sound transducers arranged inside said housing, where the housing has two sides arranged on either side of a x-y plane with a mutual distance between said sides measured along a z-axis orthogonal to the x-y plane, and a front facing side and a rear facing side, and a top and a bottom, wherein a. A first sound transducer is arranged inside a first cavity inside said loudspeaker housing, where said first cavity has a narrow first slit in the y-direction provided in the rear facing side, where said first slit has a width z1 in the z-direction, and a length y1 in the y-direction where the length y1 in the y-direction is larger than the width z1 in the z-direction; b. A second sound transducer is arranged inside a second cavity inside said loudspeaker housing, separate from said first cavity, and where said second cavity is provided with a narrow second slit in the y-direction provided in the front facing side, where said second slit has a width z2 in the z-direction, and a length y2 in the y-direction, where the length y2 in the y-direction is larger than the width z2 in the z-direction.

Claims

1. Loudspeaker (1) comprising a housing (10) and a plurality of sound transducers (22,30,40) arranged inside said housing (10), where the housing (10) has two sides (11,12) arranged on either side of a x-y plane with a mutual distance between said sides (11,12) measured along a z-axis orthogonal to the x-y plane, and a front facing side (14) and a rear facing side (16), and a top (18) and a bottom (20), wherein a. A first sound transducer (22) is arranged inside a first cavity (24) inside said loudspeaker housing (10), where said first sound transducer comprises a membrane, where said first cavity (24) has a narrow first slit (26) in the y-direction provided in the rear facing side (16), where said first slit (26) has a width z1 in the z-direction, and a length y1 in the y-direction where the length y1 in the y-direction is larger than the width z1 in the z-direction; b. A second sound transducer (30) is arranged inside a second cavity (34) inside said loudspeaker housing (10), separate from said first cavity (24), where said second sound transducer comprises a membrane and where said second cavity (34) is provided with a narrow second slit (36) in the y-direction provided in the front facing side (14), where said second slit (36) has a width z2 in the z-direction, and a length y2 in the y-direction, where the length y2 in the y-direction is larger than the width z2 in the z-direction, where the first sound transducer (22) is tilted such that the cavity (24) between the first sound transducer's membrane and the housing side (12) covering the front of the first sound transducer (22) is wedge-shaped with the thick end of the wedge-shaped cavity adjacent to the slit (26), where the two sides (11,12) are not parallel, and where the distance between the two sides along the front facing side (14) is smaller than the distance between the two sides along the rear facing side (16).

2. Loudspeaker according to claim 1 wherein with respect to the first slit (26) the width z1 is between 10-60% of the largest dimension of the membrane of the first sound transducer (22) and where the length y1 is between 50-300% of the largest dimension of the membrane of the first sound transducer (22).

3. Loudspeaker according to claim 1 where with respect to the second slit (36) the width z2 is between 10-60% of the largest dimension of the membrane of the second sound transducer (30) and where the length y2 is between 50-300% of the largest dimension of the membrane of the second sound transducer (30).

4. Loudspeaker according to claim 1 where a third sound transducer (40) is arranged in the front facing side (14), said third sound transducer (40) arranged in a separate third cavity or in an acoustic volume created behind the membrane of the first sound transducer (22).

5. Loudspeaker according to claim 1 wherein the first sound transducer (22) mainly emits sound along an axis W, where said axis W is at an angle of between 45° and 90° relative to the x-y plane and where said axis W is substantially parallel to the x-z plane.

6. Loudspeaker according to claim 1 wherein the second sound transducer (30) mainly emits sound along an axis K where said axis K is at an angle of between 45° and 90° relative to the x-y plane and where said axis K is substantially parallel to the x-z plane.

7. Loudspeaker according to claim 1 where the second sound transducer (30) is tilted such that any resonance occurring in the second cavity (34) is moved to a frequency as high as possible while leaving space for an optional absorbent material (38) for damping the resonance.

8. Loudspeaker according to claim 1 wherein the distance between the sides (11,12) in the z-direction is between 30% and 150% of the largest dimension of the membrane of the first sound transducer (22), and where the distance between the top (18) and bottom (20) is between 150% and 500% of the largest dimension of the membrane of the first sound transducer (22) and where the distance between the front facing side (14) and the rear facing side (16) is between 100% and 350% of the largest dimension of the membrane of the first sound transducer (22).

9. Loudspeaker according to claim 1 wherein the front facing side (14) and/or the rear facing side (16) are curved or semi-circular when projected onto the x-z plane.

10. Loudspeaker according to claim 1 wherein the first sound transducer (22) is a woofer, the second sound transducer (30) is a midrange sound transducer and the optional third sound transducer (40) is a tweeter, and where the sound transducers are selected to cover a combined frequency range from 40 to 25,000 Hz.

Description

DESCRIPTION OF THE DRAWING

(1) The invention will now be explained with reference to the accompanying drawing where

(2) FIGS. 1 and 2 illustrate an embodiment of the invention where the housing sides have been removed from the unit in order to illustrate the construction of the loudspeaker;

(3) FIGS. 3, 4 and 5 illustrate schematic cross-sections of possible embodiments;

(4) FIG. 6 illustrates a schematic side view of a loudspeaker.

DETAILED DESCRIPTION OF THE INVENTION

(5) In FIG. 1 is illustrated an embodiment of the invention where the housing sides have been removed from the unit in order to illustrate the construction of the loudspeaker. The loudspeaker 1 has a housing 10, which has been partly removed in this illustration, but see also FIGS. 3-6. The housing 10 has two sides 11,12. The sides 11,12 are arranged on either side of an x-y plane as defined by the x- and y-axes in FIG. 1. Orthogonal to the x-y plane is indicated a z-axis such that the sides 11,12 of the housing 10 are arranged at a mutual distance on either side of the x-y plane where the distance is measured along the z-axis. Furthermore, the loudspeaker 1 has a front facing side 14 and a rear facing side 16. Furthermore, a top 18 and a bottom 20 is provided.

(6) A first sound transducer 22 is arranged in a separate first cavity 24 (see FIGS. 1 and 3). This sound transducer 22 is provided with an acoustic volume 28 behind the sound transducer 22. The acoustic volume 28 is arranged on the rear side of the loudspeaker membrane, i.e. the opposite side to where it is intended that sound is emitted. The acoustic volume 28 extending throughout a large part of the volume of the loudspeaker housing 10 to maximise the acoustic performance of the sound transducer 22. The sound transducer 22 is tilted from a traditional position in the rear facing side 16 mainly emitting sound along the x-axis to a position where it will mainly emit sound along an axis W, where said axis W is at an angle of between 45° and 90° relative to the x-y plane and where said axis W is substantially parallel to the x-z plane. Said first cavity 24 is provided with a narrow first slit 26 (see FIGS. 2 and 3). The slit 26 is provided in the rear facing side 16 of the housing 10 and in this embodiment spans almost the entire height of the loudspeaker 1 in the y direction. The slit 26 allows the sound from the first sound transducer 22 to move in and out of the cavity 24 through the slit 26 in the rear facing side 16 in a direction substantially parallel to the x-y plane, despite the tilting of the sound transducer 22.

(7) A second sound transducer 30 is arranged in a separate second cavity 34 (see FIGS. 2 and 4). This sound transducer 30 is provided with a separate acoustic volume 32 behind the sound transducer 30. This sound transducer 30 is, as is the case with the first sound transducer 22 discussed above, also tilted with respect to the x-y plane such that it will mainly emit sound along an axis K where said axis K is at an angle of between 45° and 90° relative to the x-y plane and where said axis K is substantially parallel to the x-z plane. As the sound transducer 30 is arranged in a separate cavity 34 provided with a slit 36, the sound will move in and out of the cavity 34 through the slit 36 in the front facing side 14 in a direction substantially parallel to the x-y plane due to the slit 36 provided in the cavity 34 and despite the tilting of the sound transducer 30.

(8) Furthermore, the cavity 34 is optionally provided with acoustic damping material 38 occupying at least part of the cavity 34. The acoustic damping material preventing unwanted acoustical resonances and distortion.

(9) In FIGS. 3, 4 and 5 are illustrated schematic cross-sections through a loudspeaker embodiment according to the invention. In FIG. 5 the cross-section depicts a cross-section in an upper part of the loudspeaker 1, where a tweeter 40 is arranged on a front face 14, and in contact with the acoustic volume 28 behind the first sound transducer 22. This is possible as the tweeter 40 is closed with its own integrated acoustic volume. The cross-section in FIG. 4 is taken where the midrange sound transducer 30 is present in its separate cavity 34, such that the sound emitted by the midrange sound transducer 30 will be emitted through the slit 36 towards the listener's position. As the woofer and midrange sound transducers 22,30 may have overlapping frequency ranges the separation of the two types of speakers in separate cavities 24,34 guards against damaging interference between the sound transducers which may create distortion to the emitted sound.

(10) A further aspect illustrated in the cross-sections in FIGS. 3 and 4 is the possibility to have a non-rectangular cross section of a loudspeaker. The inventive concept of tilting or angling the sound transducers makes it possible to depart from normal loudspeaker designs (square boxes) and in this manner reduce the footprint or base area a loudspeaker occupies, and still retain a sound force and quality previously reserved for loudspeakers with larger dimensions. This is achieved by angling the sound transducers relative to the x-y plane as discussed above. This provides design possibilities which have hitherto not been available, and as reflected in the designs illustrated in FIGS. 1 and 2. In the particular embodiments illustrated it is foreseen that the loudspeaker unit 1 may be a stand-alone unit, including the necessary electronic circuitry, energy storage, and communication means in order to emit sound from a remote source. Naturally, the loudspeaker may also be a more conventional speaker, being hard wired to a power source also supplying signals to the loudspeaker.

(11) In the figures are illustrated wedge-shaped designs, but the provision of angling the speakers relative to the x-y plane provides freedom to almost create any shape of the loudspeaker unit.

(12) As already discussed above the high frequency sound transducers must be arranged such that the sound emission is substantially directed towards a listener's position and therefore in embodiments of the invention where a third sound transducer 40 for example being a tweeter is arranged, this tweeter may be arranged as illustrated in FIG. 5 where the sound transducer 40 emits sound substantially directly towards a listening position along the x-axis. Typically, tweeters will have a smaller dimension and as such it is possible to arrange the tweeter between the housing sides 11,12 such that the tweeter faces towards to listening position (corresponding to the x-axis).

(13) In the side view of a loudspeaker according to the present invention as illustrated in FIG. 6, it may be seen that the woofer 22 is substantially arranged for emitting sound almost perpendicular to the x-y plane whereas the midrange sound transducer 30 being tilted the other way as evident from FIG. 4 emits sound in a less perpendicular direction than the woofer 22 and finally that the tweeter 40 emits sound directly in the x direction. The cavities 24,34 as well as the slits 26,36 facilitate that the sound from the sound transducers 22, 30 are directed in determined directions and as such the sound impression from the sound emitted from a loudspeaker as illustrated with reference to the figures is perceived as if the sound transducer units had been arranged in a more traditional manner. By arranging the sound transducer units as described above it becomes possible to achieve the slim design as illustrated in the cross sections in FIGS. 3, 4 and 5 and at the same time maintain a high-quality sound.