Abstract: A dual-diaphragm loudspeaker driver assembly can include a multiple pole magnet structure, and first and second pole piece assemblies can be provided on opposite first and second sides of the multiple pole magnet structure. In an example, each pole piece assembly defines an airgap over a polarity transition region on a respective side of the magnet structure. First and second voice coils can be provided in respective ones of the airgaps, wherein each of the voice coils is coupled to a respective diaphragm assembly, and at least one acoustic tuning port can be configured to provide a damped acoustic communication path between first and opposite second sides of each diaphragm assembly.

Abstract: A dual-diaphragm loudspeaker driver assembly can include a multiple pole magnet structure, and first and second pole piece assemblies can be provided on opposite first and second sides of the multiple pole magnet structure. In an example, each pole piece assembly defines an airgap over a polarity transition region on a respective side of the magnet structure. First and second voice coils can be provided in respective ones of the airgaps, wherein each of the voice coils is coupled to a respective diaphragm assembly, and at least one acoustic tuning port can be configured to provide a damped acoustic communication path between first and opposite second sides of each diaphragm assembly.

Abstract: The present disclosure pertains to a rotationally triply symmetric three axis magnetic antenna system having substantial isolation among the three axes, including a three axis skew orthogonal magnetic antenna system and device utilizing the antenna system. The antenna system comprising three substantially identical magnetic antenna elements disposed symmetrically about a reference point such that the magnetic axes from the three antenna elements are orthogonal to one another in direction and do not intersect one another. The three antenna elements are positioned in a substantial cross coupling null from one another to minimize cross coupling. The arrangement yields packaging efficiency for compact electronic devices. A 1, 1, diameter embodiment is disclosed. A location system utilizing the antenna system is disclosed. Methods for producing the antenna are disclosed. A moldable triple coil holder for the antenna system is described.

Abstract: The present invention pertains to a selective proximity detection system. A selective proximity detection system comprises at least one proximity tag, a plurality of sensor nodes, and at least one alert node. A sensor nodes comprises a proximity detector capable of detecting proximity with respect to the proximity tag, and a motion detector. In a preferred embodiment, a motion detector is an infrared detector. In alternate embodiments, a motion detector may employ video, radar motion sensing, or sensing of scattered RF signals, preferably FM broadcast signals whose half wavelength is comparable in dimension to the height of a typical person. In a preferred embodiment, a proximity detector is a NFER locator-receiver and a proximity tag is a NFER tag transmitter. In alternate embodiments, a proximity detector may employ ZigBee, WiFi, Bluetooth, passive scattering of ambient RF signals or other means of proximity detection.

Abstract: The present disclosure pertains to a rotationally triply symmetric three axis magnetic antenna system having substantial isolation among the three axes, including a three axis skew orthogonal magnetic antenna system and device utilizing the antenna system. The antenna system comprising three substantially identical magnetic antenna elements disposed symmetrically about a reference point such that the magnetic axes from the three antenna elements are orthogonal to one another in direction and do not intersect one another. The three antenna elements are positioned in a substantial cross coupling null from one another to minimize cross coupling. The arrangement yields packaging efficiency for compact electronic devices. A 1, 1, diameter embodiment is disclosed. A location system utilizing the antenna system is disclosed. Methods for producing the antenna are disclosed. A moldable triple coil holder for the antenna system is described.