A speaker horn with rotatable radiation characteristics has a base body in the form of an opening funnel with a rotationally symmetrical inner wall in the radiation area and an insert mounted so that it can rotate relative to the base body. The insert covers part of the rotationally symmetrical inner wall acoustically and causes the rotatable radiation characteristic of the speaker horn.

An acoustic microphone assembly for surveillance into a protected space includes a microphone including a transducer and a diagram adapted for picking up acoustic sound waves, electronic circuitry for processing input, a power source, and an audio output wire or trace for delivering processed digital sound to a sound system, a cover plate having at least two bolt openings for mounting to a base plate on a wall or structure the cover plate covering an opening there through into the protected space, the cover plate accepting an orthogonal mounting of the microphone, and a sound diffraction pattern of different sized openings placed through the cover plate, the sound diffraction pattern located in alignment to the mounted microphone head and having a foot print roughly equal to the circumference of the head of the microphone.

A portable instrument amplification system includes a cabinet having a top cabinet member, a bottom cabinet member, and a plurality of side cabinet members. The portable instrument amplification system also includes at least one sealed chamber having a front chamber member, a side chamber member, a rear chamber member, at least one speaker driver, at least one side passive radiator, and at least one cabinet bracing secured in at least one corner of the sealed chamber. The cabinet bracing includes a cabinet bracing body, and at least one stiffener attached to the cabinet bracing body. The portable instrument amplification system also includes at least one front-facing port having a rear port member vertically attached between the side chamber member and a second side cabinet member behind the at least one side passive radiator, and a bass phase plug vertically disposed facing the at least one side passive radiator.

A loudspeaker arrangement comprises a transducer arranged in a loudspeaker enclosure, the loudspeaker enclosure enclosing a rear part of the transducer, and an aperture-defining structure (hereinafter, the aperture) mounted on a front side of the transducer in a direction of propagation of sound emitted by the transducer. The transducer is configured to emit sound within a wide frequency range, and at frequencies of above a predetermined threshold. The aperture is configured to amplify sound at predetermined frequencies or within a predetermined frequency range within the wide frequency range, and to let sound at all other frequencies within the wide frequency range pass essentially unaltered. The loudspeaker enclosure is sized such that the resonance frequency of the loudspeaker enclosure matches the resonance frequency of the transducer in free air, wherein the resonance frequency of the transducer in free air is below the predetermined threshold.

A compression driver for an omnidirectional loudspeaker includes a motor assembly and a dome diaphragm disposed coaxially above and operably connected to the motor assembly, the diaphragm having a convex surface and a concave surface. The compression driver includes a phasing plug having a top portion and a bottom portion having a concave bottom surface disposed adjacent the convex surface of the diaphragm and defining a compression chamber therebetween. The phasing plug includes a plurality of conduits extending through the bottom portion for sound waves to travel and converging to form an annular exit, the top portion including a plurality of radially expanding channels acoustically connected to the annular exit. Actuation of the diaphragm by the motor assembly generates sound waves within the compression chamber which travel through the annular exit and the radially-expanding channels to create a generally horizontal 360° radiation pattern of the sound waves from the compression driver.

A voice-controlled electronic device that includes a device housing having a longitudinal axis bisecting opposing top and bottom surfaces and a side surface extending between the top and bottom surfaces. The device can further include one or more microphones disposed within the device housing and distributed radially around the longitudinal axis; a processor configured to execute computer instructions stored in a computer-readable memory for interacting with a user and processing voice commands received by the one or more microphones and first transducer and second transducers configured to generate sound waves within different frequency ranges.

A compression driver includes a dome diaphragm having a convex surface and a concave surface and a phasing plug having a base portion with a first side and an opposed second side. The base portion first side is disposed adjacent the convex surface of the diaphragm and defines a compression chamber therebetween. The base portion includes a plurality of channels that extend therethrough from the first side to the second side for sound waves to travel through the base portion, the plurality of channels converging to form an annular exit of the compression driver.

A voice-controlled electronic device that includes an axisymmetric device housing having a longitudinal axis bisecting opposing top and bottom surfaces and a side surface extending between the top and bottom surfaces. The device can further include a plurality of microphones disposed within the device housing and distributed radially around the longitudinal axis; a processor configured to execute computer instructions stored in a computer-readable memory for interacting with a user and processing voice commands received by the plurality of microphones and first and second transducers configured to generate sound waves within different frequency ranges.

A coaxial compression driver including a housing, a first vibrating membrane for lower frequencies housed in the housing and facing a first compression chamber in communication with a first acoustic conduit, a second vibrating membrane for higher frequencies housed in the housing and facing a second compression chamber in communication with a second acoustic conduit, and a passive acoustic low pass filter housed in the first acoustic conduit, where the first and second vibrating membranes are arranged in the housing coaxial with respect to each other, where the first and second acoustic conduits converge into a common output acoustic conduit, and where the passive low pass filter is a lumped parameters filter which prevents frequencies above a predetermined cutoff frequency from passing from the second to the first acoustic conduit and allows frequencies below the predetermined cutoff frequency to pass from the first to the common output acoustic conduit.

A sound diffuser includes a first annular control member, a second annular control member, and a third annular control member. The first annular control member includes a first communication hole and an annular inclined plate that surrounds the first communication hole and is inclined relative to an axial direction of the first communication hole. The second annular control member includes a second communication hole and an annular inclined plate that surrounds the second communication hole, houses the first annular control member therein, and is inclined relative to an axial direction of the second communication hole. The third annular control member has a plurality of third communication holes and surrounds the second annular control member.