Abstract: An apparatus for modifying a responsive liquid held in a barrel or other liquid container includes a transducer for producing vibration energy within the audio frequency range in response to an audio signal input and a coupler affixed to the transducer such that vibration energy produced in the transducer is transferred to the coupling device. The coupling device has a pusher end that extends beyond the front plane of the transducer and that contacts and pushes against the barrel wall when the apparatus is tied to the barrel wall. By determining the resonances of the liquid-filled barrel, audio input signals having sufficiently high levels at determined resonant frequencies can be chosen to achieve a maximum response in the liquid contained in the barrel. The apparatus is particularly suited for the sonic aging of whisky.

Abstract: An improved filtering system for loudspeaker equalization is comprised of two filtering sections, a single pole filtering section having single pole filters for shaping the frequency response of the audio signal over the operative bandwidth of the equalized loudspeaker system, and a parametric filtering section that provides for localized parametric equalization for compensating for room or other environmental resonances. The filtering system of the invention can be used to create a wide variety of useful filter shapes, while minimizing phase distortion that can harm the transient response of phase-aligned loudspeakers of a loudspeaker system.

Abstract: A circuit for reducing noise in Class D amplifiers has a power stage voltage control means (17, 21, 22) responsive to defined signal conditions of the audio signal input (1). The power stage voltage control means is operative to lower the voltage at the supply voltage input (31) of the amplifier's switching power output stage (30) upon the detection of a defined condition in the audio signal input such that the Class-D amplifier operates at reduced voltage (“idles”) during the defined audio input signal condition.

Abstract: A loudspeaker system has a high frequency channel for driving a horn loaded high frequency transducer, and a low frequency channel for driving a low frequency transducer. A signal processing circuit is provided which has at least one first order and at least one second order cross-over circuit portion in the high channel and at least one first order and at least one second order cross-over circuit portion in the low frequency channel. These cross-over portions produce a cross-over frequency range for the loudspeaker system that is below the cut-off frequency of the horn. The signal processing circuit, including its cross-over circuit portions and in conjunction with the design of the expansion walls of the horn, extends vertical beamwidth control of the acoustic output of the loudspeaker system at the loudspeaker system's lower frequency range.

Abstract: A circuit for reducing noise in Class D amplifiers has a power stage voltage control means (17, 21, 22) responsive to defined signal conditions of the audio signal input (1). The power stage voltage control means is operative to lower the voltage at the supply voltage input (31) of the amplifier's switching power output stage (30) upon the detection of a defined condition in the audio signal input such that the Class-D amplifier operates at reduced voltage (“idles”) during the defined audio input signal condition.

Abstract: The present invention provides a new device and method for enhancing the electrical properties of the thick metal backer/electrically conductive thermoset adhesive/printed circuit board or card assembly. The enhanced electrical properties are obtained by providing a thin bondline of conductive adhesive that is essentially void free.

Abstract: A circuit and method provides for the protection of transducers from over excursion, particularly for the protection of transducers for audio loudspeakers. A frequency dependent excursion limiter circuit has an initial summing stage followed by a shaping filter stage. A clamping function is provided at the summing stage, or at a separate stage between the summing stage and the shaping filter stage, for clamping the driving signal at a predetermined maximum voltage if the driving signal exceeds the predetermined maximum voltage level. The shaping filter stage provides a frequency response shaping function based on a predetermined frequency response shaping criteria which is related to the frequency dependent excursion limits of the transducers being protected from mechanical overload. An inverse shaping filter function is provided at the initial summing stage by providing feedback from the shaping filter stage, thus eliminating the need for a separate inverse shaping filter circuit before clamping.

Abstract: The present invention provides a new device and method for enhancing the electrical properties of the thick metal backer/electrically conductive thermoset adhesive/printed circuit board or card assembly. The enhanced electrical properties are obtained by providing a thin bondline of conductive adhesive that is essentially void free.

Abstract: The present invention provides a new device and method for enhancing the electrical properties of the thick metal backer/electrically conductive thermoset adhesive/printed circuit board or card assembly. The enhanced electrical properties are obtained by providing a thin bondline of conductive adhesive that is essentially void free.

Abstract: A method and correction circuit for improving and controlling the listening window and response of a two-way loudspeaker system utilizing a horn-loaded high frequency driver. The correction circuit includes adjustable active all-pass and band-pass filters, in a specific arrangement, coupled with conventional cross-over filters to achieve a maximally flat amplitude and phase response acoustically throughout a preferred listening window. A spectrum analyzer measures the near-field responses of the individual and combined transducers while adjustments are made. A phase shifting circuit is included in the low frequency channel which results in improved near-field to far-field response consistency and significantly improves the subjective characteristics of the high frequency horn.

Abstract: A circuit for improving the transient behavior of a two-way loudspeaker system includes a crossover circuit with high selectivity, amplitude and phase correction circuitry for separately correcting the amplitude and phase responses of the high and low frequency drivers in their mounting environment, and correction circuitry for correcting the composite amplitude and phase response of the overall loudspeaker system after insertion of the crossover. A further phase offset technique and circuit provides for introducing frequency dependent phase shift in the loudspeaker system's high or low frequency channels for offsetting the phase responses of the high and low frequency drivers within the crossover frequency range. According to the phase offset technique of the invention, phase shift is added, preferably in the high frequency channel, until composite amplitude response curves observed on-axis and at different vertical angles off-axis are forced to be consistent.

Abstract: A circuit for improving the transient behavior of a two-way loudspeaker system includes a crossover circuit with high selectivity, amplitude and phase correction circuitry for separately correcting the amplitude and phase responses of the high and low frequency drivers in their mounting environment, and correction circuitry for correcting the composite amplitude and phase response of the overall loudspeaker system after insertion of the crossover. A further phase offset technique and circuit provides for introducing frequency dependent phase shift in the loudspeaker system's high or low frequency channels for offsetting the phase responses of the high and low frequency drivers within the crossover frequency range. According to the phase offset technique of the invention, phase shift is added, preferably in the high frequency channel, until composite amplitude response curves observed on-axis and at different vertical angles off-axis are forced to be consistent.