Abstract: An acoustic filter suitable for an electro-acoustic transducer includes a relatively high frequency driver and a relatively low frequency driver situated on a common axis. The acoustic filter includes a baffle body having an outer side and an inner side, such that the outer side serves as a baffle for the high frequency driver. The inner side forms a first wall of a Helmholtz resonator including a chamber and a vent duct communicating with the chamber.

Abstract: A loudspeaker assembly for use in a vehicle, the vehicle including a cabin and one or more cabin walls, the assembly including a plurality of drivers fitted to a common enclosure, the enclosure including a vent duct passing through a cabin wall of a vehicle such that one side of the loudspeaker assembly is in acoustic communication with a volume of air external to the cabin of the vehicle and the other side of the loudspeaker assembly is in acoustic communication with air in the cabin of the vehicle.

Abstract: An acoustic filter suitable for an electro-acoustic transducer is provided. The acoustic filter has a relatively high frequency driver and a relatively low frequency driver situated on a common axis. The acoustic filter includes a baffle body having an outer side and an inner side, such that said outer side serves as a baffle for said high frequency driver and said inner side forms a first wall of at least one Helmholtz resonator including a chamber and a vent duct communicating with said chamber.

Abstract: Apparatus for managing and/or reducing harmonic distortion arising with an audio signal including a phase generator for generating at least one phase-difference signal or a reference audio signal generated by the phase generator, wherein the or each constant phase difference is adapted to provide cancellation of the harmonic distortion components arising along the signal path. Respective amplifier channels for receiving and separately amplifying the audio signal acting as a reference audio signal are also provided as are respective loudspeaker channels for receiving and separately producing sound corresponding to the amplified audio wherein each loudspeaker channel has substantially equal performance parameters and is adapted to radiate the sound relative to other loudspeaker channels to produce a combined sound that corresponds to the audio signal with harmonic distortion components that are reduced compared to the harmonic distortion components arising along the signal path.

Abstract: Apparatus for managing and/or reducing harmonic distortion arising with an audio signal including a phase generator for generating at least one phase-difference signal or a reference audio signal generated by the phase generator, wherein the or each constant phase difference is adapted to provide cancellation of the harmonic distortion components arising along the signal path. Respective amplifier channels for receiving and separately amplifying the audio signal acting as a reference audio signal are also provided as are respective loudspeaker channels for receiving and separately producing sound corresponding to the amplified audio wherein each loudspeaker channel has substantially equal performance parameters and is adapted to radiate the sound relative to other loudspeaker channels to produce a combined sound that corresponds to the audio signal with harmonic distortion components that are reduced compared to the harmonic distortion components arising along the signal path.

Abstract: An amplifier circuit is disclosed suitable for feeding a loudspeaker system having plural drivers. The amplifier circuit has an output stage and plural output connectors such that there is an output connector for each driver, wherein the output stage is connected separately to each output connector for independent connection to each driver. A method of feeding a loudspeaker system having plural drivers with an amplifier circuit having an output stage is also disclosed.

Abstract: The transparent conductive film includes on a transparent film base a transparent electrode layer in which a transparent conductive oxide layer and a patterned metal layer are stacked in contact with each other. The maximum layer thickness of the transparent electrode layer is 300 nm or less. The metal layer has a metal pattern width of 1 ?m or more and 8 ?m or less, and the metal pattern coverage ratio of 0.4% or more and 3.2% or less. It is preferable that the metal layer has a layer thickness of 50 nm or more and 250 nm or less. It is also preferable that the pattern shape of the metal layer is of stripes, mesh, dots or the like.

Abstract: An amplifier circuit is disclosed suitable for feeding a loudspeaker system having plural drivers. The amplifier circuit has an output stage and plural output connectors such that there is an output connector for each driver, wherein the output stage is connected separately to each output connector for independent connection to each driver. A method of feeding a loudspeaker system having plural drivers with an amplifier circuit having an output stage is also disclosed.

Abstract: A loudspeaker assembly is disclosed for use in a loudspeaker system having infinite baffle topology. The assembly comprises a driver including a cone and a basket and at least one Helmholtz resonator including a chamber and a vent duct communicating with the chamber and adapted to pass through the infinite baffle. The chamber is dimensioned to provide a tuned frequency well above an operating band associated with the driver. The cross sectional area and length of the vent duct may be set to provide control over duct air noise and low frequency extension. A method of tuning a loudspeaker assembly for use in a loudspeaker system having infinite baffle topology is also disclosed.

Abstract: A loudspeaker assembly is disclosed for use in a loudspeaker system having infinite baffle topology. The assembly comprises a driver including a cone and a basket and at least one Helmholtz resonator including a chamber and a vent duct communicating with the chamber and adapted to pass through the infinite baffle. The chamber is dimensioned to provide a tuned frequency well above an operating band associated with the driver. The cross sectional area and length of the vent duct may be set to provide control over duct air noise and low frequency extension. A method of tuning a loudspeaker assembly for use in a loudspeaker system having infinite baffle topology is also disclosed.

Abstract: A loudspeaker system suitable for a confined space includes an electro-acoustic transducer and an enclosure for the electro-acoustic transducer. The enclosure combines a second order topology to produce a rising acoustic response (40) for the system at a second order rate and a helmholtz resonator adapted to modify the rate of rise of the response relative to the second order rate such that the response is attenuated relative to the second order rate but is accentuated relative to a flat response, within a substantial part of a passband of the system at least at a selected frequency or frequencies. The system has means included in an electrical path driving the electro-acoustic transducer for equalizing the rising response to provide extended dynamic headroom at least at the selected frequency or frequencies.