Abstract: Systems and methods are provided that detect at least one of a look direction or a focal depth of a user and execute control actions based upon the detected look direction and/or focal depth.

Abstract: An acoustic diaphragm made at least in part from an expanded material. The expanded material includes one or more of cellulose, synthetic fibers and glass fibers. The expanded material has more than about 55% by volume voids.

Abstract: An electro-acoustic transducer includes a cone, a voice coil connected to the cone, and magnetic circuit that defines a gap within which the voice coil is disposed. The magnetic circuit is configured for creating magnetic flux across the gap for the voice coil to interact with, thereby to drive motion of the cone. A conductor is included for providing an input signal to the voice coil. A first portion of the conductor is fixedly secured to the magnetic circuit such that the first portion of the conductor does not move relative to the magnetic circuit while the cone is in motion.

Abstract: An acoustic diaphragm made at least in part from an expanded material. The expanded material includes one or more of cellulose, synthetic fibers and glass fibers. The expanded material has more than about 55% by volume voids.

Abstract: An electro-acoustic transducer includes a cone, a voice coil connected to the cone, and magnetic circuit that defines a gap within which the voice coil is disposed. The magnetic circuit is configured for creating magnetic flux across the gap for the voice coil to interact with, thereby to drive motion of the cone. A conductor is included for providing an input signal to the voice coil. A first portion of the conductor is fixedly secured to the magnetic circuit such that the first portion of the conductor does not move relative to the magnetic circuit while the cone is in motion.

Abstract: A multi-channel audio system including first combining circuitry, for combining a first spectral band of a first plurality channels to provide a first bass audio signal stream; second combining circuitry, for combining the first spectral band of a second plurality channels to provide a second bass audio signal stream; and third combining circuitry, for combining a second spectral band, the second spectral band including lower frequencies than the first spectral band, of the first plurality of channels and the second plurality of channels to provide a third bass audio signal stream.

Abstract: An electrical apparatus to sense current through a load includes a first input terminal having a first input voltage relative to a reference, a second input terminal having a second input voltage relative to the reference, a first load terminal of the load having a first load voltage relative to the reference, a second load terminal of the load having a second load voltage relative to the reference, a first current sensing element connected between the first input terminal and the first load terminal and a second current sensing element connected between the second input terminal and the second load terminal. A first sense voltage is determined by a relationship between the first input voltage and the second load voltage and a second sense voltage is determined by a relationship between the second input voltage and the first load voltage.

Abstract: An electrical apparatus to sense current through a load includes a first input terminal having a first input voltage relative to a reference, a second input terminal having a second input voltage relative to the reference, a first load terminal of the load having a first load voltage relative to the reference, a second load terminal of the load having a second load voltage relative to the reference, a first current sensing element connected between the first input terminal and the first load terminal and a second current sensing element connected between the second input terminal and the second load terminal. A first sense voltage is determined by a relationship between the first input voltage and the second load voltage and a second sense voltage is determined by a relationship between the second input voltage and the first load voltage.

Abstract: An audio system including an audio power amplifier, a transducer electrically connected to the audio power amplifier, an enclosure coupled to the transducer, and a secondary resonant element coupled to the enclosure. An electrical feedback signal representative of the transducer current is negatively fed back to the audio power amplifier to synthesize a positive output impedance.

Abstract: Investment management systems and methods are disclosed that solve an objective function subject to certain investment constraints to calculate a set of assets for an investment portfolio. In certain embodiments, the systems and methods comprise selecting from a plurality of assets a set of assets that improves net expected returns over a current set of assets in a portfolio. The systems and methods use asset-asset interaction decoupling techniques to eliminate matrix-inversion programming. In certain embodiments, with a function comprising net expected returns of the assets, a portfolio constraint, and a Lagrange multiplier, one or more correlations between assets can be removed such that each asset can be processed independently of other assets.

Abstract: A loudspeaker, amplifier, media source, user interface, and mechanical interface are all contained in a single unit. The unit has a first portion configured to mount in a vehicle radio mounting location and a second portion configured to extend significantly outside the vehicle radio mounting location.

Abstract: A GPS-timing module for a wireless communication system comprises an “in line” power-over-Ethernet system and a modular surge protection means for protecting the device and a connected wireless access point/backhauls from power or Ethernet surges. The “in line” Power-over-Ethernet system allows the GPS-timing device to directly power the wireless access point/backhaul to which it is providing a GPS-timing signal. The modular surge protection means comprises a removable component that can be quickly replaced following a power surge. The GPS-timing module further comprises a plurality of DIP switches. The DIP switches allow a user to turn the GPS-timing module on and off, turn the communication module on or off, switch between the GPS-timing module's internal GPS-antenna and external GPS-antenna, and remotely revert the communication module to it “default” mode from its “normal” mode.

Abstract: An audio device has passive radiators that are driven by acoustic drivers. The passive radiators are arranged so that the net mechanical vibration is minimized.

Abstract: An apparatus for reducing baffle vibration includes a baffle that is subject to vibration. A first transducer that is seated in the baffle includes a first diaphragm that is acoustically coupled to a listening area in a vehicle and also acoustically coupled to a cavity in the vehicle. A first input signal applied to the first transducer causes the first diaphragm to move in a first direction, thereby generating an acoustic output. A second transducer is mechanically coupled to the first transducer. The second transducer includes a second diaphragm that is acoustically coupled to the first diaphragm and also acoustically coupled to the listening area. A second input signal applied to the second transducer causes the second diaphragm to move in a second direction that is substantially opposite to the first direction to reduce a vibration imparted to the baffle while substantially maintaining the acoustic output.

Abstract: A multi-channel audio system including first combining circuitry, for combining a first spectral band of a first plurality channels to provide a first bass audio signal stream; second combining circuitry, for combining the first spectral band of a second plurality channels to provide a second bass audio signal stream; and third combining circuitry, for combining a second spectral band, the second spectral band including lower frequencies than the first spectral band, of the first plurality of channels and the second plurality of channels to provide a third bass audio signal stream.

Abstract: A multi-channel audio system including first combining circuitry, for combining a first spectral band of a first plurality channels to provide a first bass audio signal stream; second combining circuitry, for combining the first spectral band of a second plurality channels to provide a second bass audio signal stream; and third combining circuitry, for combining a second spectral band, the second spectral band including lower frequencies than the first spectral band, of the first plurality of channels and the second plurality of channels to provide a third bass audio signal stream.

Abstract: A loudspeaker, amplifier, media source, user interface, and mechanical interface are all contained in a single unit. The unit has a first portion configured to mount in a vehicle radio mounting location and a second portion configured to extend significantly outside the vehicle radio mounting location.

Abstract: An apparatus for reducing baffle vibration includes a baffle that is subject to vibration. A first transducer that is seated in the baffle includes a first diaphragm that is acoustically coupled to a listening area in a vehicle and also acoustically coupled to a cavity in the vehicle. A first input signal applied to the first transducer causes the first diaphragm to move in a first direction, thereby generating an acoustic output. A second transducer is mechanically coupled to the first transducer. The second transducer includes a second diaphragm that is acoustically coupled to the first diaphragm and also acoustically coupled to the listening area. A second input signal applied to the second transducer causes the second diaphragm to move in a second direction that is substantially opposite to the first direction to reduce a vibration imparted to the baffle while substantially maintaining the acoustic output.

Abstract: An audio system including an audio power amplifier, a transducer electrically connected to the audio power amplifier, an enclosure coupled to the transducer, and a secondary resonant element coupled to the enclosure. An electrical feedback signal representative of the transducer current is negatively fed back to the audio power amplifier to synthesize a positive output impedance.

Abstract: A transducer assembly for a vehicle is described. The transducer assembly includes an enclosure formed from an interior component of the vehicle. The enclosure includes a front section defining an aperture and a rear section defining a volume. The assembly also includes a baffle that is located within a periphery of the aperture so as to form a port between the baffle and the enclosure. A transducer is mechanically coupled to the baffle.