Abstract: A loudspeaker system having an enclosure having a narrow opening or slot for radiating high frequency acoustic energy. The loudspeaker system has a cover member defining a slot between the cover member and a boundary of a listening space. The loudspeaker system may also include a fixed or adaptive equalizer for modifying frequency response anomalies resulting from the interaction of the acoustic energy, the narrow opening, and the boundary.

Abstract: An electroacoustical transducer has an enclosure having a thickness substantially smaller than the width and the depth. The transducer includes a first rigid sheet, a second rigid sheet, and a spacing structure for spacing the first rigid sheet from the second rigid sheet to define an acoustic enclosure, having a top, a bottom and a side edge. The top includes the first rigid sheet and the bottom includes the second rigid sheet. The transducer includes an acoustic transducer for exchanging sound waves with the acoustic enclosure. The enclosure has a plurality of outlet points.

Abstract: An electroacoustical transducer has an enclosure having a thickness substantially smaller than the width and the depth. The transducer includes a first rigid sheet, a second rigid sheet, and a spacing structure for spacing the first rigid sheet from the second rigid sheet to define an acoustic enclosure, having a top, a bottom and a side edge. The top includes the first rigid sheet and the bottom includes the second rigid sheet. The transducer includes an acoustic transducer for exchanging sound waves with the acoustic enclosure. The enclosure has a plurality of outlet points.

Abstract: A valve regulates fluid displacement in a damper assembly, for example, displacement of hydraulic fluid in a sealed shock absorber. The valve is placed between a portion of fluid at one pressure and regulates the passage of fluid through an aperture or passage to a portion of fluid at a lower pressure by a blocking member which moves to obstruct the aperture in accordance with a desired level of damping. The blocking member is, or is driven by, an electroactive device, such as a bimorph actuator formed of ferroelectric material.

Abstract: A valve regulates fluid displacement in a damper assembly, for example, displacement of hydraulic fluid in a sealed shock absorber. The valve is placed between a portion of fluid at one pressure and regulates the passage of fluid through an aperture or passage to a portion of fluid at a lower pressure by a blocking member which moves to obstruct the aperture in accordance with a desired level of damping. The blocking member is, or is driven by, an electroactive device, such as a bimorph actuator formed of ferroelectric material. In one embodiment, the blocking member is a bimorph which covers the aperture, and is flexibly displaced by passage of pressurized fluid through the aperture. A controller provides an electrical actuation signal to move the bimorph toward or away from the aperture, augmenting or decreasing its closing bias to affect both the threshold flow initiation pressure and the rate of flow once the passage opens.

Abstract: A valve regulates fluid displacement in a damper assembly, for example, displacement of hydraulic fluid in a sealed shock absorber. The valve is placed between a portion of fluid at one pressure and regulates the passage of fluid through an aperture or passage to a portion of fluid at a lower pressure by a blocking member which moves to obstruct the aperture in accordance with a desired level of damping. The blocking member is, or is driven by, an electroactive device, such as a bimorph actuator formed of ferroelectric material. In one embodiment, the blocking member is a bimorph which covers the aperture, and is flexibly displaced by passage of pressurized fluid through the aperture. A controller provides an electrical actuation signal to move the bimorph toward or away from the aperture, augmenting or decreasing its closing bias to affect both the threshold flow initiation pressure and the rate of flow once the passage opens.

Abstract: A loudspeaker system includes an upper frequency assembly that radiates acoustical energy having spectral components in the audio frequency range above a predetermined upper frequency, typically at the high end of the bass frequency range between 150 and 200 Hz. The assembly includes a ported enclosure with a front face enclosing a loudspeaker driver with a cone adjacent to the front face of diameter slightly less than at least one of the height and width of the enclosure.

Abstract: Electroacoustical apparatus includes according to one aspect structure for providing a sound field concentrated at a restricted listening region corresponding substantially to a human head while being spaced from the restricted listening region. According to another aspect an electroacoustical transducer is located at the interface of an acoustic waveguide and a ported enclosure.

Abstract: A loudspeaker enclosure has an inside volume. At least one port characterized by predetermined mass intercouples the inside volume and the region outside the enclosure. Each port has a smoothly flared input end within the inside volume and smoothly flared output end adjacent to the region outside the inside volume. The port defines a boundary between the acoustic mass therein and the inside volume, the boundary typically being defined by an ellipse, and in a particular form by the rotation of an ellipse about the axis of a port. Typically, the length of the port corresponds substantially to the major diameter of the ellipse.