Abstract: A wearable ballistic impact protection system detects impacts to a body. The system includes multiple sensors for detecting vibration. The sensed vibrations are converted to electrical signals which are filtered. Electronic components are provided to determine whether the filtered signal have frequency and amplitude characteristics of impact that cause injury to a body. Preferably, the sensors are Piezo-electric film sensing elements. Information regarding the extent of the impact and injuries to the body may be transmitted to a remote location so that medics or other personnel may be informed to the extent of injuries to the body so that they may provide medical assistance.

Abstract: A system for tensioning a membrane within a frame for a loudspeaker or a microphone is characterized by a frame containing an opening, a membrane connected to an exterior surface of the frame and spanning the frame opening, and a tensioning device connected with the frame for deflecting a portion of the membrane within the frame opening. The tensioning device is compliant thereby allowing the membrane to exhibit a high degree of flexure both within and beyond a plane containing the membrane.

Abstract: A system for tensioning a membrane within a frame for a loudspeaker or a microphone is characterized by a frame containing an opening, a membrane connected to an exterior surface of the frame and spanning the frame opening, and a tensioning device connected with the frame for deflecting a portion of the membrane within the frame opening. The tensioning device is compliant thereby allowing the membrane to exhibit a high degree of flexure both within and beyond a plane containing the membrane.

Abstract: A dipole loudspeaker includes a rigid support containing an opening and a generally planar multi-layered flexible diaphragm mounted on the support and extending across the opening. The diaphragm is formed of a plurality of layers of thin flexible membrane material, each of the layers having a different height and containing a thin electrical conductor arranged in a predetermined pattern on one surface thereof. The conductor patterns on each of the membranes have different masses, whereby the membrane defines along its height areas of various thickness and varying mass whereby the membrane is suitable for more accurately reproducing or generating high and low frequencies when the electrical conductors are connected with a source of sound signal currents. A plurality of magnets are mounted in spaced relation opposite at least one surface of the membrane and the conductor patterns for vibrating the membrane to reproduce the sound in response to the sound signal currents through the conductor.

Abstract: A dipole loudspeaker includes a rigid support containing an opening and a generally planar multi-layered flexible diaphragm mounted on the support and extending across the opening. The diaphragm is formed of a plurality of layers of thin flexible membrane material, each of the layers having a different height and containing a thin electrical conductor arranged in a predetermined pattern on one surface thereof. The conductor patterns on each of the membranes have different masses, whereby the membrane defines along its height areas of various thickness and varying mass whereby the membrane is suitable for more accurately reproducing or generating high and low frequencies when the electrical conductors are connected with a source of sound signal currents. A plurality of magnets are mounted in spaced relation opposite at least one surface of the membrane and the conductor patterns for vibrating the membrane to reproduce the sound in response to the sound signal currents through the conductor.

Abstract: A dipole loudspeaker includes a rigid support containing an opening and a generally planar multi-layered flexible diaphragm mounted on the support and extending across the opening. The diaphragm is formed of a plurality of layers of thin flexible membrane material, each of the layers having a different height and containing a thin electrical conductor arranged in a predetermined pattern on one surface thereof. The conductor patterns on each of the membranes have different masses, whereby the membrane defines along its height areas of various thickness and varying mass whereby the membrane is suitable for more accurately reproducing or generating high and low frequencies when the electrical conductors are connected with a source of sound signal currents. A plurality of magnets are mounted in spaced relation opposite at least one surface of the membrane and the conductor patterns for vibrating the membrane to reproduce the sound in response to the sound signal currents through the conductor.

Abstract: A method and apparatus for improving the accuracy in locating psychoacoustic images in plural channels of related audio signals. Signals are cross-fed from one channel to another in an out-of-phase relationship with respect to the signals in the other channel. The phase relationship is such that it has not more than a single maximum with respect to frequency. Cross-feeding is limited to frequency components less than a predetermined value in the range of 1,000 to 5,000 Hertz. The overall gain of each of the audio channels in the frequency range of approximately 100 to 1,000 Hertz is greater when a signal is applied to that channel only, than when the signal is applied to both channels. When the same signal is applied to both channels, a dip in gain occurs for frequencies in the range of approximately 200 to 900 Hertz. Above the dip, the gain is relatively flat and below the dip, the gain increases gradually.

Abstract: Enhanced pyschoacoustic imagery is achieved in an audio signal processing circuit for processing plural channels of related audio signals. Asymmetric bi-directional audio signal cross-feed is established between first and second audio signal processing channels, for example. The cross-fed signal components are combined in an out-of-phase relationship with respect to related audio signals already passing through a given channel. The asymmetry is designed so as to complement the asymmetry which is believed to be present in a listener's brain processing of perceived acoustic signals due to the naturally occurring left or right half brain dominance of the listener. In other embodiments both symmetric and asymmetric, cross-feeding is limited to signal components below a predetermined frequency.

Abstract: A loudspeaker enclosure has a loudspeaker driver mounted on a surface of the enclosure such that the driver has an exposed front face to produce sound waves which are sought to be transmitted to a listening space exterior of the loudspeaker enclosure. A plurality of successive spaced limp or semi-limp non-porous pliable barriers are positioned in an opening between the interior and exterior spaces of the enclosure so as to relieve rear pressure of the loudspeaker driver while attenuating the rear sound waves and providing a damping effect on the loudspeaker driver.

Abstract: A high fidelity playback system is described using a plurality of speakers in conjunction with a conventional stereo system and an auditory interface unit which provides improved high fidelity playback. The system includes for example, two front high fidelity speakers in the normal stereophonic position, and a second pair of high fidelity speakers placed on an axis defined by the ears of the listener. The amplifier feeds the front speakers directly. The interface unit attenuates the left and right channel signals according to the inter-channel signal level differential, and distributes them in proper proportion to the second pair of speakers to create full stereophonic realism with enhanced depth perception and positioning of the original sound sources.Alternatively, only two speakers are used.