Electrical circuitry adapted to drive a dual-coil loudspeaker having a primary voice coil and a second voice coil connected in parallel with the primary voice coil, the second voice coil being in series with an LC resonant circuit of impedance Z.sub.mf, further comprising an inductance compensation filter of impedance Z.sub.if in parallel with the LC resonant circuit.

Embodiments of the invention provide methods and apparatus for measuring and characterizing a loudspeaker. In particular, the non-linear response of the loudspeaker can be determined. Embodiments of the invention also provide methods and apparatus for processing audio input signals, for example, so as to linearize the output of a given loudspeaker.

Embodiments of the invention provide methods and apparatus for processing audio input signals, for example, so as to linearize the output of a given loudspeaker. An audio processor is provided, for modifying an audio signal to be provided to a loudspeaker, the audio processor comprising: a first filter stage, for applying to an audio signal a linear model describing an excursion of the loudspeaker in response to a given input signal, the linear model containing only linear terms, and for generating one or more excursion signals; a plurality of second filters for receiving the one or more excursion signals, each of the second filters configured to apply to a respective one of a plurality of frequency bands in the one or more excursion signals the inverse of a model describing an excursion of the loudspeaker in response to a given input signal; and a combiner for combining the outputs of each of the plurality of second filters. At least a first one of the plurality of second filters applies the inverse of a non-linear model describing an excursion of the loudspeaker in response to a given input signal, the non-linear model comprising one or more non-linear parameters.

The present invention relates to an acoustic signal supply circuit of at least one loudspeaker (HP) incorporating a filtering device of the resonance peak of said at least one loudspeaker (HP) occurring at a given frequency, characterized in that the filtering device of the resonance peak of said at least one loudspeaker (HP) is incorporated either into the first instrumentation ground circuit or in the feedback loop, this filtering device being purely electrical in the form an impedance incorporated in the first instrumentation ground circuit or in the feedback loop, the impedance parameters being predetermined as a function of the resonance peak to be filtered of said at least one loudspeaker (HP).

A corrector is configured to transform audio signals to compensate for unwanted distortion characteristics of a loudspeaker. A tuning filter is configured to transform audio signals to incorporate desired distortion characteristics associated with a target loudspeaker. By chaining together the tuning filter and the corrector, an audio signal can be modified so that the loudspeaker, when outputting the audio signal, has response characteristics of the target loudspeaker.

A receiver assembly comprising a first and a second receiver housing and a spout. The second receiver housing is positioned over a first sound outlet port of the first receiver housing and the spout is positioned over a second outlet port of the second receiver housing. An acoustic duct is located between the first and second receiver housing acoustically connecting the first sound outlet port to the spout and is provided with an acoustic mass.

A receiver assembly comprising a first and a second receiver housing and a spout. The second receiver housing is positioned over a first sound outlet port of the first receiver housing and the spout is positioned over a second outlet port of the second receiver housing. An acoustic duct is located between the first and second receiver housing acoustically connecting the first sound outlet port to the spout and is provided with an acoustic mass.

A signal converter includes a magnetic circuit, a diaphragm, a first coil, a second coil, and a variable resistor. The magnetic circuit has a magnetic gap. The diaphragm is disposed over an opening of the magnetic circuit. The first coil is disposed in the magnetic gap and configured to output an electrical signal based on vibration of the diaphragm. The second coil is disposed in the magnetic gap and configured to brake the diaphragm. The variable resistor is connected to a first end and a second end of the second coil and configured to form a closed loop circuit together with the second coil.

In at least one embodiment, an audio amplifier system is provided. The system includes a loudspeaker and an audio amplifier. The loudspeaker transmits an audio output into a listening environment. The audio amplifier is programmed to receive an audio input signal and to generate an excursion signal corresponding to a first excursion level of the voice coil based on the audio input signal. The audio amplifier is further programmed to limit the excursion signal to reach a maximum excursion level and to determine a target pressure for an enclosure of the loudspeaker based on the maximum excursion level. The audio amplifier is further programmed to generate a target current signal based at least on the target pressure and to convert the target current signal into a target voltage signal to a target driving signal to drive the voice coil to reach the maximum excursion level.

There is provided an audio transmission method, comprising: wirelessly connecting an audio receiver device to a first audio streaming device; transmitting a first audio stream from the first audio streaming device using a first protocol to the audio receiver device, wherein at least one audio data packet is transmitted in each frame in at least one audio packet slot; and scanning, by the audio receiver device, while receiving the first audio stream from the first audio streaming device, during at least one scan window (S) for frequency hopping synchronization (FHS) packets (F) transmitted from a second audio streaming device in a second audio stream using a second protocol. The scanning activity enables reception of at least one audio packet per frame of the first audio stream by preventing collision of the at least one scan window with at least one audio packet slot (A) per frame (R).