Abstract: An acoustic transducer comprises one or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers. The diaphragms may be driven directly, inertially or fluidically. If diaphragms are driven by rods that pass through holes in the diaphragms, noise may be generated by air that leaks through the pass-through holes. This noise may be reduced or eliminated by measures that reduce or eliminate the air leakage.

Abstract: An acoustic transducer includes a housing, a plurality of diaphragms suspended from the housing and separated into one or more groups, and one or more motors combined with the housing that operate in response to an electrical signal. The diaphragms of each group are driven by a respective motor to which all the diaphragms in the group are coupled and at least one motor has an indirect coupling with no direct mechanical connection to the diaphragms driven thereby. One or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers.

Abstract: A method for operating an acoustic transducer is provided. The acoustic transducer includes a moving element and a fixed element, wherein the moving element is coupled to surrounding air. In the method, a signal-independent magnetic field is generated to urge the moving element into a rest position when no input signal is received; and a force is generated in response to the input signal and applying that force to the moving element to urge the moving element away from the rest position. The moving element is controlled by a combined influence of the signal-independent magnetic field and the signal-dependent force to generate acoustic vibrations in response to an audio input signal.

Abstract: A method for operating an acoustic transducer is provided. The acoustic transducer includes a moving element and a fixed element, wherein the moving element is coupled to surrounding air. In the method, a signal-independent magnetic field is generated to urge the moving element into a rest position when no input signal is received; and a force is generated in response to the input signal and applying that force to the moving element to urge the moving element away from the rest position. The moving element is controlled by a combined influence of the signal-independent magnetic field and the signal-dependent force to generate acoustic vibrations in response to an audio input signal.

Abstract: An acoustic transducer includes a housing, a plurality of diaphragms suspended from the housing and separated into one or more groups, and one or more motors combined with the housing that operate in response to an electrical signal. The diaphragms of each group are driven by a respective motor to which all the diaphragms in the group are coupled and at least one motor has an indirect coupling with no direct mechanical connection to the diaphragms driven thereby. One or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers.

Abstract: An acoustic transducer comprises one or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers. The diaphragms may be driven directly, inertially or fluidically. If diaphragms are driven by rods that pass through holes in the diaphragms, noise may be generated by air that leaks through the pass-through holes. This noise may be reduced or eliminated by measures that reduce or eliminate the air leakage.

Abstract: An improved electrodynamic acoustic transducer eliminates or reduces the need for flexible or elastic materials to suspend an internal magnetic element by using both static and dynamic signal-dependent magnetic fields to control its movement. In one implementation, the transducer has a magnet that moves within a surrounding tube. This tube in turn supports one or more electromagnetic coils that generate a dynamic signal-dependent magnetic field that causes the internal magnetic element to vibrate. The surrounding tube also supports one or more magnets whose location on the tube is fixed and whose magnetic fields provide appropriate restoring forces acting on the internal magnetic element. These fixed magnets may be replaced or supplemented by ferromagnetic materials.

Abstract: An acoustic transducer comprises one or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers. The diaphragms may be driven directly, inertially or fluidically. If diaphragms are driven by rods that pass through holes in the diaphragms, noise may be generated by air that leaks through the pass-through holes. This noise may be reduced or eliminated by measures that reduce or eliminate the air leakage.

Abstract: An acoustic transducer comprises one or more electromagnetic motors that drive one or more sets of multiple diaphragms to provide acoustically efficient loudspeaker systems having dimensions that allow use in applications that would be difficult or impossible with traditional transducers. The diaphragms may be driven directly, inertially or fluidically. If diaphragms are driven by rods that pass through holes in the diaphragms, noise may be generated by air that leaks through the pass-through holes. This noise may be reduced or eliminated by measures that reduce or eliminate the air leakage.

Abstract: Acoustical characteristics of rooms or other environments in which audio systems operate may be improved by equalization derived from measures of relative acoustic energy storage of the audio system such as a Relative Acoustic-energy Decay Spectrum (RADS). A RADS may be calculated from a measure of absolute energy storage such as RT60 values obtained from models or measurements of the audio system, and normalized with respect to a measure of acoustic energy storage of a reference system.

Abstract: This invention comprises a system to compensate for the noise level inside a vehicle by measuring the music level and the noise level in the vehicle through the use of analog to digital conversion and adaptive digital filtering, including a sensing microphone in the vehicle cabin to measure both music and noise; preamplification and analog to digital (A/D) conversion of the microphone signal; A/D conversion of a stereo music signal; a pair of filters that use an adaptive algorithm such as the known Least Mean Squares ("LMS") method to extract the noise from the total cabin sound; an estimation of the masking effect of the noise on the music; an adaptive correction of the music loudness and, optionally, equalization to overcome the masking effect; digital to analog (D/A) conversion of the corrected music signal; and transmission of the corrected music signal to the audio system.

Abstract: This invention comprises a system to compensate for the noise level inside a vehicle by measuring the music level and the noise level in the vehicle through the use of analog to digital conversion and adaptive digital filtering, including a sensing microphone in the vehicle cabin to measure both music and noise; preamplification and analog to digital (A/D) conversion of the microphone signal; A/D conversion of a stereo music signal; a pair of filters that use an adaptive algorithm such as the known Least Mean Squares ("LMS") method to extract the noise from the total cabin sound; an estimation of the masking effect of the noise on the music; an adaptive correction of the music loudness and, optionally, equalization to overcome the masking effect; digital to analog (D/A) conversion of the corrected music signal; and transmission of the corrected music signal to the audio system.