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 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 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 speaker system including an enclosure, a first acoustic driver engaged with the enclosure, and two or more horns configured to output a sound from the first acoustic driver to a front plane of the enclosure. In one embodiment, the two or more horns may be folded and planar. In one embodiment, the speaker system may include a second acoustic driver, which may be installed above or below the first acoustic driver. The second acoustic driver may be larger or smaller or the same size when compared to the first acoustic driver.

A speaker system including an enclosure, a first acoustic driver engaged with the enclosure, and two or more horns configured to output a sound from the first acoustic driver to a front plane of the enclosure. In one embodiment, the two or more horns may be folded and planar. In one embodiment, the speaker system may include a second acoustic driver, which may be installed above or below the first acoustic driver. The second acoustic driver may be larger or smaller or the same size when compared to the first acoustic driver.

A passive cardioid acoustical system, or loudspeaker, is described which is driven with a single electrical signal and provides a useful reduction of low-frequency sound intensity in the rearward direction while producing relatively high low-frequency sound intensity in the forward direction. This is accomplished by an acoustical circuit which modifies the magnitude and phase of sound radiated by the interior side of a vibrating diaphragm or diaphragms, and combines it with the sound radiated by the exterior side of the diaphragm or diaphragms, so as to cancel part of the rearward radiation and reinforce the forward radiation. The passive cardioid loudspeaker described employs an improved acoustical circuit which allows improved efficiency, as well as greater flexibility with regard to the size, maximum output, and effective frequency range of the loudspeaker, as compared to prior art.

A passive cardioid acoustical system, or loudspeaker, is described which is driven with a single electrical signal and provides a useful reduction of low-frequency sound intensity in the rearward direction while producing relatively high low-frequency sound intensity in the forward direction. This is accomplished by an acoustical circuit which modifies the magnitude and phase of sound radiated by the interior side of a vibrating diaphragm or diaphragms, and combines it with the sound radiated by the exterior side of the diaphragm or diaphragms, so as to cancel part of the rearward radiation and reinforce the forward radiation. The passive cardioid loudspeaker described employs an improved acoustical circuit which allows improved efficiency, as well as greater flexibility with regard to the size, maximum output, and effective frequency range of the loudspeaker, as compared to prior art.

A loudspeaker baffle that provides variable sound patterns is described. The baffle may support non-low frequency sound sources and a waveguide to provide varying sound beam patterns. The baffle may include a center mount adapted to receive a plurality of audio outputs and a plurality of low frequency apertures to receive a plurality low frequency output. The waveguide may be formed from a front face of the baffle. The front face may be intermediate the center mount and the low frequency apertures. The front face may include a continuously varying waveguide surface with a first waveguide portion adjacent a first audio output of the plurality of audio outputs providing a first sound pattern and a second waveguide portion adjacent a second audio output of the plurality of audio outputs providing a second sound pattern that is different than the first sound pattern.

In one embodiment of an audio system, a transducer can be coupled to a passive acoustic directional amplifier to provide various benefits and improvements, including improvements to: speech intelligibility, signal-to-noise ratio, effective equivalent input noise, at-a-distance acoustic signal reception, and directional preference. In another embodiment, the shape of an interior surface of a passive acoustic directional amplifier is provided. In another embodiment, the material properties of an interior surface of a passive acoustic directional amplifier are provided.

A method and apparatus for a co-located Radio Frequency Identification (RFID) device and ultrasonic device includes an RFID reader loop antenna element oriented parallel to a reflector panel. An ultrasonic emitter is disposed through an aperture in the reflector panel with a horn that extends through the loop element. The horn can serve as a mounting structure for the antenna element. A diameter of the aperture is less than one-quarter wavelength of an operating frequency of the RFID reader loop antenna element. The aperture is located in the reflector panel near a minimum E-field area of the RFID reader loop antenna element.