Abstract: A speaker comprises a permanent magnet (2) and a coil (8) positioned around the permanent magnet (2) and attached to a membrane (10), wherein the membrane comprises an elastomer of thickness less than 0.3 mm and with a Young's modulus below 100 MPa.

Abstract: A speaker including a single coil for both normal voice and for creating an HAC field. A large coil may be provided in combination with a strong magnet. The components of the speaker may be designed so as to maximize the space available for the voice coil and for the magnet.

Abstract: A moving system (3) for a piezoelectric speaker (1) may include a membrane (4) and a piezoelectric layer (5) attached thereto, wherein a movement of the moving system (3) in a main direction (MD) is substantially caused by dilatation/contraction of the piezoelectric layer (5) transverse to the main direction (MD). To provide an advantageous frequency response of the moving system (3), it is built up asymmetrically with respect to the moving characteristics. Accordingly, the modes are frequency shifted on the one hand and of less influence on the other. Hence, the frequency response of an inventive speaker (1) has less elevations and depressions in the frequency response. In a preferred embodiment the local compliance and/or the shape of the moving system (3) is asymmetric with respect to any point in the plane of the moving system (3).

Abstract: A compound membrane (100) for an acoustic device (200), the compound membrane (100) comprising a first layer (101) and a second layer (102), wherein a value of Young's modulus of the second layer (102) does not vary more than essentially 30% in a temperature range between essentially ?20° C. and essentially +85° C.

Abstract: An acoustic device (500), comprising an oscillatory membrane (501) which comprises a transducing element (503) and a frame (504) adapted for accommodating the membrane (501) in an accommodation plane, wherein the membrane (501) is accommodated in the frame (504) in such a manner that a translational motion of the membrane (501) in at least one direction of the accommodation plane is made possible.

Abstract: A speaker comprises a permanent magnet (2) and a coil (8) positioned around the permanent magnet (2) and attached to a membrane (10), wherein the membrane comprises an elastomer of thickness less than 0.3 mm and with a Young's modulus below 100 MPa.

Abstract: A membrane for an acoustic transducer is provided which comprises a first portion having a first stiffness, and a second portion comprising a first subsection having a second stiffness and a second subsection having a third stiffness, wherein the second stiffness and the third stiffness are different.

Abstract: A membrane for an electroacoustic transducer is disclosed having a first area, a second area, which is arranged for translatory movement in relation to said first area, and a third area, which connects said first area and said second area, wherein local, planar spring constants along a closed line within said third area encompassing said second area, are determined in such a way that local, translatory spring constants along said line in a direction of said translatory movement are substantially constant or exclusively have substantially flat, mutual changes.

Abstract: A membrane for an electroacoustic transducer is disclosed having a first area, a second area, which is arranged for translatory movement in relation to said first area, and a third area, which connects said first area and said second area, wherein local, planar spring constants along a closed line within said third area encompassing said second area, are determined in such a way that local, translatory spring constants along said line in a direction of said translatory movement are substantially constant or exclusively have substantially flat, mutual changes.

Abstract: A membrane (2?) for an electroacoustic transducer (1) is disclosed having a first area (A1), a second area (A2), which is arranged for translatory movement in relation to said first area (A1), and a third area (A3), which connects said first (A1) and said second area (A2), wherein local, planar spring constants (psc) along a closed line (L) within said third area (A3) encompassing said second area (A2), are determined in such a way that local, translatory spring constants (tsc) along said line (L) in a direction (DM) of said translatory movement are substantially constant or exclusively have substantially flat, mutual changes.

Abstract: An acoustic device (500), comprising an oscillatory membrane (501) which comprises a transducing element (503) and a frame (504) adapted for accommodating the membrane (501) in an accommodation plane, wherein the membrane (501) is accommodated in the frame (504) in such a manner that a translational motion of the membrane (501) in at least one direction of the accommodation plane is made possible.

Abstract: A membrane for an electroacoustic transducer is disclosed, wherein said membrane (201) comprises a rigid membrane portion (202) having an edge (203); a flexible membrane portion (204) being connected to the rigid membrane portion (202) along the edge (203); wherein an exterior surface (205) of the flexible membrane portion (204) is concave in an idle state of the membrane (201) and shaped such that a change of the curvature of said exterior surface (205) contributes to an air volume shifted by the rigid membrane portion (202) when membrane (201) is excited.

Abstract: An acoustic device (200, 300) comprising an oscillatory compound membrane (201) comprising a plurality of layers (202, 203, 205), wherein one of the plurality of layers (202, 203, 205) is a thermoplastic layer (203, 205), wherein the thermoplastic layer (203, 205) is joined to at least one further component (204, 206, 207) of the acoustic device (200).

Abstract: A compound membrane (100) for an acoustic device (200), the compound membrane (100) comprising a first layer (101) and a second layer (102), wherein a value of Young's modulus of the second layer (102) does not vary more than essentially 30% in a temperature range between essentially ?20° C. and essentially +85° C.

Abstract: A membrane (2) for an electroacoustic transducer (1) is disclosed, wherein a thickness (d) of said membrane (2) and an average Young's modulus (Eavg) of said membrane (2) are chosen in such a way that the critical load (Fbc), which causes the membrane (2) to buckle and/or crinkle, is increased compared to a reference membrane. The reference membrane made of Polycarbonate has the same shape, dimension, and stiffness in its direction of movement (MOV) as said membrane (2). According to the result of investigations on buckling and/or crinkling, said effect occurs with different critical buckling/crinkling loads for membranes of the same shape and dimension, but made of different materials, even when the stiffness of the membranes in their direction of movement—and hence their resonant frequency—is identical.

Abstract: The present invention discloses a moving system (3) for a piezoelectric speaker (1), comprising a membrane (4) and a piezoelectric layer (5) attached thereto, wherein a movement of the moving system (3) in a main direction (MD) is substantially caused by dilatation/contraction of the piezoelectric layer (5) transverse to said main direction (MD). Accordingly, there is no translatory movement when exciting the moving system (3), but only a bending movement. To provide an advantageous frequency response of the moving system (3), it is built up asymmetrically with respect to the moving characteristics. Accordingly, the modes are frequency shifted on the one hand and of less influence on the other. Hence, the frequency response of an inventive speaker (1) has less elevations and depressions in the frequency response. The concrete design of a moving system (3) is preferably done by the use of a computer simulation based on a finite elements method.

Abstract: A membrane (2?) for an electroacoustic transducer (1) is disclosed having a first area (A1), a second area (A2), which is arranged for translatory movement in relation to said first area (A1), and a third area (A3), which connects said first (A1) and said second area (A2), wherein local, planar spring constants (psc) along a closed line (L) within said third area (A3) encompassing said second area (A2), are determined in such a way that local, translatory spring constants (tsc) along said line (L) in a direction (DM) of said translatory movement are substantially constant or exclusively have substantially flat, mutual changes.

Abstract: A membrane (2) for an electroacoustic transducer (1) is disclosed, wherein a thickness (d) of said membrane (2) and an average Young's modulus (Eavg) of said membrane (2) are chosen in such a way that the critical load (Fbc), which causes the membrane (2) to buckle and/or crinkle, is increased compared to a reference membrane. The reference membrane made of Polycarbonate has the same shape, dimension, and stiffness in its direction of movement (MOV) as said membrane (2). According to the result of investigations on buckling and/or crinkling, said effect occurs with different critical buckling/crinkling loads for membranes of the same shape and dimension, but made of different materials, even when the stiffness of the membranes in their direction of movement—and hence their resonant frequency—is identical.