An acoustic transducer comprises a transducer substrate, and an aperture having a non-circular perimetral shape defined through the transducer substrate. A diaphragm is disposed on the transducer substrate and coupled to a surface of the transducer substrate via at least one diaphragm anchor such that a gap is defined between the diaphragm and the transducer substrate, and an outer periphery of the diaphragm extends radially outwards of a rim of the aperture such that a portion of the diaphragm overhangs the aperture.

A speaker box includes a housing having a receiving space; a sound generator having a diaphragm received in the receiving space for vibrating along a vibration direction; a sound aperture formed in the housing for communicating the sound generator with an outside of the speaker box; a dustproof member positioned by the housing and covering completely the sound aperture. The dustproof member includes a first dustproof element fixed to the housing and completely covering the sound aperture; a second dustproof element fixed to the housing; a gasket plate sandwiched between the first and second dustproof elements. The gasket forms a through hole aligned with the sound aperture and completely covered by the second dustproof element.

A frame member is attached to an opening in an outer light-reflection plate. The frame member is composed of an inner frame part, and an outer frame part disposed around the inner frame part. A light extraction part is formed between the outer frame part and the inner frame part. The inner frame part is constituted by a separate extraction part that extracts acoustic vibrations and light. A space of the separate extraction part includes, on both ends, a sound intake port on an internal space side where a sound source is disposed, and a sound extraction port formed in the top of the inner frame part so as to open toward the outside of an LED illumination device. The sound intake port and the sound extraction port are formed separated from each other by a prescribed distance, and the space is formed continuously in the inner frame part so as to connect the sound intake port and the sound extraction port.

Active noise control (ANC), including active and adaptive noise cancellation (ANC) with non-voice-coil transducers having highly linear transfer functions, such as planar transducers, planar magnetic transducers, electro-static transducers, and piezo-electric transducers. This active and adaptive noise cancellation (ANC) may be used with: planar transducer headphones and earphones; open-backed and closed-back headphones and earphones; in-ear earphones, and phase plugs.

Active noise control (ANC), including active and adaptive noise cancellation (ANC) with non-voice-coil transducers having highly linear transfer functions, such as planar transducers, planar magnetic transducers, electro-static transducers, and piezo-electric transducers. This active and adaptive noise cancellation (ANC) may be used with: planar transducer headphones and earphones; open-backed and closed-back headphones and earphones; in-ear earphones, and phase plugs.

A frame member is attached to an opening in an outer light-reflection plate. The frame member is composed of an inner frame part, and an outer frame part disposed around the inner frame part. A light extraction part is formed between the outer frame part and the inner frame part. The inner frame part is constituted by a separate extraction part that extracts acoustic vibrations and light. A space of the separate extraction part includes, on both ends, a sound intake port on an internal space side where a sound source is disposed, and a sound extraction port formed in the top of the inner frame part so as to open toward the outside of an LED illumination device. The sound intake port and the sound extraction port are formed separated from each other by a prescribed distance, and the space is formed continuously in the inner frame part so as to connect the sound intake port and the sound extraction port.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.

A playback device comprises an electroacoustic transducer; an acoustic waveguide in fluid communication with the transducer; and a housing delimiting an opening of the waveguide, the opening extending around an axis passing through the transducer. The opening may have a radial distance from the axis that varies with an azimuthal angle about the axis. An acoustic path length within the waveguide, between the transducer and the opening, is substantially constant and independent of azimuthal angle about the axis.