Abstract: According to an example aspect of the present invention, there is provided an audio amplifier for use with a limited power source, the audio amplifier having: a power input terminal, a signal input terminal, a first DC to DC converter having an input connected to the power input terminal, an electrical energy storage device connected to an output of the first DC to DC converter, a second DC to DC converter having an input connected to the electrical energy storage device, an amplifier conductively connected to the output of the second DC to DC converter so as to be powered by the output of the second DC to DC converter, the amplifier also being conductively connected to the signal input terminal so as to receive a signal for amplification, and an output of the amplifier configured to be connected to a transducer such that the transducer may be driven by the amplifier.

Abstract: According to an example aspect of the present invention, there is provided A controllable loudspeaker, the loudspeaker comprising a speaker element and a digital signal processor comprising at least one processing core and at least one memory including computer program code, the at least one memory and the computer program code being configured to receive a multicasted control signal, alter the behavior of the loudspeaker in response to the said control signal, wherein the altering of the behavior comprises applying settings stored in the memory of the digital signal processor of the loudspeaker.

Abstract: According to an example aspect of the present invention, there is provided a sound system, the sound system comprising: a first loudspeaker, comprising at least one first speaker element, a second loudspeaker, comprising at least one second speaker element, wherein the first and second loudspeaker have at least partially overlapping frequency ranges, and the first speaker is configured to produce a response within at least one first operating band defined within the frequency range of the first speaker, and the second speaker is configured to produce a response within at least one second operating band defined within the frequency range of the second speaker, and the first and second operating bands do not overlap, and wherein the overall response of the sound system at a first location is comprised of the response within the first operating band and the response within the second operating band.

Abstract: The present invention relates to a loudspeaker including an enclosure having front portion, side portions and back portion defining an inner volume, the front portion is formed as a waveguide surface and includes at least one driver in the center of the waveguide surface and is capable to radiate the main acoustic power of the loudspeaker to ambient volume in direction of first acoustic axis, and an additional driver attached to the enclosure. In accordance with the invention the additional driver is attached inside the enclosure such that a sub volume is formed inside the inner volume, the sub volume limited by the driver, spacers between the driver and the front portion, and the front portion of the enclosure, and at least one port is adapted to open from the sub volume to ambient volume either to side portion or back portion of the enclosure and at least one resonator acoustically connected to the sub volume, the resonator being tuned to at least one of unwanted resonances of the sub volume.

Abstract: A novel loudspeaker with a reflex enclosure that has the reflex port terminating to the bottom of the enclosure. The loudspeaker further includes a stand which is removably attached to the bottom of the enclosure so as to create a clearance between the bottom and the surface supporting the loudspeaker.

Abstract: According to an example aspect of the present invention, there is provided a method for calibrating a headphone including an amplifier with a memory and signal processing properties, the method comprising steps for determining a desired sound attributes for the headphone, and setting signal processing parameters in the amplifier in order to obtain the desired sound attributes either by measurement or based on the received input information from a user of the headphones.

Abstract: According to an example aspect of the present invention, there is provided a method comprising: calculating a head-related transfer function for a user, the calculation based at least in part on gathered data comprising at least video material and at least one supplemental image, the at least one supplemental image comprising an image of a transparent measurement device superimposed over at least one biological detail of an user, and transmitting said head-related transfer function.

Abstract: According to an example aspect of the present invention, there is provided a method for forming a binaural filter for a stereo headphone in order to preserve the sound quality of the headphone, whereby the sum of the direct and crosstalk paths from loudspeakers to each ear have flat magnitude responses.

Abstract: A novel diaphragm assembly, transducer and manufacturing method is here in proposed making use of a diaphragm assembly including a diaphragm having a first diaphragm component and a second diaphragm component. Both diaphragm components extend between respective inner perimeter and outer rim. The outer rim of the first diaphragm component overlaps with and is attached to the second diaphragm component at an overlap section. A voice coil assembly is connected to the inner perimeter of the second diaphragm component.

Abstract: According to an example aspect of the present invention, there is provided a Method for regularizing the inversion of a stereo headphone transfer function for headphone equalization, characterized by using the equation for the equalization: H S ? ? 1 - 1 ? ( ? ) = H * ? ( ? ) ? H ? ( ? ) ? 2 + ? ^ ? ( ? ) ? D ? ( ? ) = H * ? ( ? ) ? H ? ( ? ) ? 2 + [ ? ? ( ? ) + ? 2 ? ( ? ) ] ? D ? ( ? ) . in which equation HSI?1(?) is sigma inversion H*(?) is complex conjugate of a response D(?) is a delay filter introduced to produce a causal inverse HRI?1(?) H*(?) a response ?(?) is headphone reproduction bandwidth, ?(?) an estimation of the regularization needed inside that bandwidth.

Abstract: A novel loudspeaker with a reflex enclosure that has the reflex port terminating to the bottom of the enclosure. The loudspeaker further includes a stand which is removably attached to the bottom of the enclosure so as to create a clearance between the bottom and the surface supporting the loudspeaker.

Abstract: In accordance with an example aspect of the present invention, an apparatus is provided, the apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the apparatus at least to derive, from first digital information describing a system impulse response caused by a loudspeaker to a first location in a first room, second digital information describing a cancelling impulse response, determine, for samples comprised in the second digital information, at least one of a delay value describing how much the samples are to be shifted in time and a gain factor describing how much the samples' magnitude is to be adjusted, so that an energy associated with a sum of the system impulse response and the cancelling impulse response is reduced, and employ the determined at least one of the delay value and the gain factor to generate a cancelling signal, and to ad

Abstract: The present invention relates to a loudspeaker including an enclosure having front portion, side portions and back portion defining an inner volume, the front portion is formed as a waveguide surface and includes at least one driver in the center of the waveguide surface and is capable to radiate the main acoustic power of the loudspeaker to ambient volume in direction of first acoustic axis, and an additional driver attached to the enclosure. In accordance with the invention the additional driver is attached inside the enclosure such that a sub volume is formed inside the inner volume, the sub volume limited by the driver, spacers between the driver and the front portion, and the front portion of the enclosure, and at least one port is adapted to open from the sub volume to ambient volume either to side portion or back portion of the enclosure.

Abstract: According to an exemplary aspect of the present invention, there is provided an apparatus comprising: at least one loudspeaker element, at least one processing core, at least one memory including computer program code, the at least one memory and the computer program configured to, with the at least one processing core, cause the apparatus to produce sound via the loudspeaker element, wherein the at least one processing core is configured to adjust the sound according to criteria stored in the at least one memory, wherein the criteria comprise a wide bandwidth roll-off using at least one parametric shelving filter.

Abstract: According to an exemplary aspect of the present invention, there is provided an apparatus comprising: at least one loudspeaker element, at least one processing core, at least one memory including computer program code, the at least one memory and the computer program configured to, with the at least one processing core, cause the apparatus to produce sound via the loudspeaker element, wherein the at least one processing core is configured to adjust the sound according to criteria stored in the at least one memory, wherein the criteria comprise a wide bandwidth roll-off using at least one parametric shelving filter.