Abstract: A method includes: performing interpolation on a second nonlinear parameter of a speaker based on direct current resistance of the speaker to obtain a third nonlinear parameter of the speaker, where the second nonlinear parameter is a nonlinear parameter preconfigured in the speaker; performing signal compensation on a first input signal of the speaker based on the third nonlinear parameter to obtain a compensated first input signal; and performing filtering on the compensated first input signal to obtain an output signal of the speaker.

Abstract: A vibrating unit includes a diaphragm and a bobbin, and a voice coil is secured to the bobbin. A detecting unit includes a moving magnet and a magnetic sensor. An annular magnet support is secured to a front edge of the bobbin, and the moving magnet is positioned and secured to the magnet support. The magnetic sensor is secured to a drive supporting unit. The moving magnet is secured to the bobbin, with the magnet support therebetween. This facilitates mounting and positioning of the moving magnet.

Abstract: A noise detecting circuit including an amplifier circuit, a filtering circuit and a comparing circuit. The amplifier circuit is arranged to amplify an input signal and output an amplified signal, wherein the input signal is received from a circuit to be detected and indicates a noise level of the circuit to be detected. The filtering circuit is coupled to the amplifier circuit and arranged to filter the amplified signal and output a filtered signal. The comparing circuit is coupled to the filtering circuit and arranged to compare the filtered signal to a reference voltage and output an output signal indicating the noise level of the circuit to be detected.

Abstract: The present disclosure relates to a magnetic circuit assembly of a bone conduction speaker. The magnetic circuit assembly may generate a first magnetic field. The magnetic circuit assembly may include a first magnetic element, and the first magnetic element may generate a second magnetic field. The magnetic circuit may further include a first magnetic guide element and at least one second magnetic element. The at least one second magnetic element may be configured to surround the first magnetic element and a magnetic gap may be configured between the second magnetic element and the first magnetic element. A magnetic field strength of the first magnetic field within the magnetic gap may exceed a magnetic field strength of the second magnetic field within the magnetic gap.

Abstract: An amplification system with an output driver stage for providing an output signal to acoustic output transducers such as speakers or haptic output devices removes signal distortion caused by output stage non-linearities by pre-distorting an input signal. The system includes the output driver stage, an input stage for receiving the input signal, and a processing block that receives the input signal and provides an output signal to the output driver stage. The processing block includes a pre-distortion circuit that applies a pre-distortion function to the input signal to generate the output signal if a signal level of the input signal is greater than a threshold amplitude, and if the signal level is less than or equal to the threshold amplitude, generates the output signal from the input signal by bypassing the pre-distortion circuit.

Abstract: A controller for an electromechanical transducer is provided. The controller comprises driving means operable to actuate a mechanical output of the transducer; impedance cancelling means operable to at least partially cancel an electrical impedance of the transducer; and linearising means between an input of the controller and the driving means. The linearising means are operable to generate an output signal by modifying an input signal of the linearising means to compensate for nonlinear behaviour of the transducer. The linearising means are operable to receive one or more state signals indicative of one or more state variables of the transducer, the one or more state signals comprising a velocity signal indicative of a velocity of the mechanical output of the transducer.

Abstract: The present invention provides an amplifier including a DAC, an analog signal processing circuit, a digital signal processing circuit, a signal detector and a driving stage is disclosed. The DAC is configured to perform a digital-to-analog conversion operation on a digital input signal to generate an analog input signal. The analog signal processing circuit is configured to generate a first processed signal according to the analog input signal and a feedback signal. The digital signal processing circuit is configured to process the digital input signal to generate a second processed signal. The signal detector is configured to detect strength of the digital input signal to generate a mode selection signal. The driving stage is configured to refer to the mode selection signal to receive one of the first processed signal and the second processed signal to generate an output signal, wherein the feedback signal is generated by the output signal.

Abstract: Deterioration in transient response characteristics of a current sensor may cause overshoot or delay. Thus, it is difficult to achieve good transient response characteristics of a magnetic field. A current sensor is provided, including: a detection unit outputting a signal corresponding to a magnetic field generated by detection current flowing through a current path; a reception unit receiving the signal corresponding to the magnetic field; a filter unit filtering the signal received by the reception unit; and an output unit outputting an output signal indicating the detection current according to the filtered signal, wherein detection gain, as gain of magnetic flux density detected by the detection unit, has a gain fluctuation band that changes with an increase in a frequency of the detection current, and the filter unit has gain that cancels out the change in the detection gain in at least a part of the gain fluctuation band.

Abstract: Described embodiments include a system (74), including a garment (76), configured to cover at least a portion of a body of a subject, one or more sound transmitters (92) coupled to the garment, configured to transmit sound (128) through the body of the subject, and a plurality of sound detectors (22, 96) coupled to the garment. The sound detectors are configured to detect the transmitted sound following passage of the transmitted sound through the body of the subject, to detect body sound (25) emanating from the body of the subject, and to generate a plurality of sound-detector outputs in response to detecting the transmitted sound and the body sound. The system further includes a processor (98), configured to process the sound-detector outputs, and to generate a processor output in response thereto. Other embodiments are also described.

Abstract: A method for calculating excursion of a diaphragm of a speaker, which includes: calculating a DC resistance based on a feedback signal of the speaker; calculating an impedance based on the feedback signal and the DC resistance; calculating a transfer function between a signal and a velocity of the diaphragm of the speaker based on the DC resistance, the impedance, and a force factor; and calculating the excursion of the diaphragm of the speaker based on an input signal and the transfer function.

Abstract: A method and a system for measuring a total sound pressure level of noise, and a computer readable storage medium are provided. The method includes: obtaining a time domain digital signal of a sound pressure signal of the noise; obtaining a frequency domain signal of the sound pressure signal according to the time domain digital signal of the sound pressure signal; obtaining a sound pressure effective value of the sound pressure signal based on the frequency domain signal and according to Parseval's theorem; and converting the sound pressure effective value into the total sound pressure level of the noise.

Abstract: A method for the identification of a receiver belonging to one of a plurality of receiver types in a hearing aid system includes supplying an electrical input signal to the receiver for sound output. The input signal is a primary signal, and a secondary signal that depends on the input signal is generated on the basis of the sound output. The secondary signal is captured by a sensor which generates an electrical sensor signal depending on the secondary signal. A phase measurement is furthermore carried out by determining a phase difference between the input signal and the sensor signal. The receiver is then identified by assigning the receiver to one of the plurality of receiver types on the basis of the phase difference. A corresponding hearing aid system and an receiver set are also provided.

Abstract: A circuit comprises a sensing resistor with a resistance Rs, a first amplifier circuit with a first gain factor G, a second amplifier circuit with a second gain factor (1/A), a third amplifier circuit, a current mirror, a buffer, and a peak voltage detector. The first amplifier circuit is coupled to the sensing resistor at a first node and a second node and to the second amplifier circuit, which is further coupled to the current mirror. The buffer is coupled to the current mirror and to the third amplifier circuit, which is further coupled to the peak voltage detector and configured to receive a voltage across a load and a voltage on a ground node. In some implementations, the load is a speaker. In some implementations, a filter is coupled between the first and the second amplifier circuits.

Abstract: A technique for estimating a set of parameter values for a lumped parameter model of a loudspeaker. The technique includes determining, via a neural network model, a first set of parameter values for the LPM of the loudspeaker based on an audio input signal and a first measured response of a loudspeaker that corresponds to the audio input signal. The technique further includes generating a first LPM response based on the first set of parameter values and comparing the first LPM response to the first measured response of the loudspeaker to determine a first error value. The technique further includes generating, via the neural network model, a second set of parameter values for the LPM of the loudspeaker based on the first error value.

Abstract: A moving-coil loudspeaker is provided, comprising a vibration system and a magnetic circuit system located below the vibration system; the vibration system including a diaphragm, a spider, and a voice coil, the diaphragm comprising a diaphragm body part and a diaphragm reinforcing part; and the magnetic circuit system including a center washer, a center magnet, and a magnetic yoke; wherein the diaphragm reinforcing part comprises a first conductive material layer, the spider comprises a second conductive material layer, and the diaphragm reinforcing part and the spider are bonded by a conductive adhesive which establishes electrically connection between the first and second conductive material layers; and wherein the first and second conductive material layers functioning as a movable plate, and the center washer, the center magnet, and the magnetic yoke functioning as a fixed plate constitute a capacitor structure for detecting a vibration displacement of the moving-coil loudspeaker.

Abstract: A speaker device 101 includes vibrating body components constituting a vibrating body, consisting of at least a voice coil 119, a diaphragm 106, and a frame 102, and magnetic circuit components constituting a magnetic circuit, consisting of at least a plate 103, a yoke 104, a magnet 105, and a center pole 112. By winding an insulation coated conductor wire 120 around an outer circumference of any of the magnetic circuit components and connecting one end and the other end of the insulation coated conductor wire, a current flows in the insulation coated conductor wire 120 and makes (+) potentials and (?) potentials that are mixed on the surface of the magnetic circuit component and cause an eddy current equal to each other instantaneously, so that generation of an eddy current can be suppressed.

Abstract: A sound signal processing method and device are provided for separating sounds of the respective sound sources even when sounds are recorded asynchronously by a plurality of devices. Specifically, the present invention comprises the steps of instructing each of the plurality of devices to output a reference signal of a different frequency, receiving each of the reference signals output from the speaker of the plurality of devices according to the instruction, receiving sound signals in which each of the reference signals output from the speaker of the plurality of devices is input into the microphone of the plurality of devices, calculating a time shift amount of each of the devices based on each of the received reference signals output from the speaker and the received sound signals, and separating the plurality of signal signals input into the microphone of the plurality of devices based on the calculated time shift amount.

Abstract: A transducer system, comprising an electrodynamic acoustic transducer (1) with a membrane (3), a plurality of voice coils (7, 8) electrically switched in series, and a magnet system (9, 10, 11) is presented, wherein just an outer tap/terminal (T2) of the serially connected voice coils (7, 8) is electrically connected to an audio output of an amplifier (17). Moreover, a method for feeding a sound signal to an electrodynamic acoustic transducer (1) is presented, wherein the voice coils (7, 8) are driven by an audio signal just via an outer tap/terminal (T2) of the serially connected voice coils (7, 8).

Abstract: Acoustic transducer systems are described herein and in particular, acoustic transducer systems involving high displacement are described. An example acoustic transducer system includes an acoustic driver, a diaphragm position sensing module for generating a position signal corresponding to a displacement of a diaphragm of the acoustic driver, and a controller operable to: receive an input audio signal; generate a control signal based at least on the input audio signal and the position signal; and transmit the control signal to a voice coil operably coupled to the diaphragm so that the voice coil moves within an air gap within the acoustic driver at least partially in response to the control signal. A height of the voice coil can correspond substantially to a gap height in some embodiments.

Abstract: An apparatus comprising: at least one filter configured to filter an electrical input signal and provide a filtered electrical input signal to at least one speaker module configured to convert the filtered electrical input signal to an acoustic signal; and a detector configured to receive the filtered electrical input signal as a first input and an electrical output signal provided by at least one microphone as a second input; wherein the detector is configured to determine at least one difference between the electrical output signal provided by the at least one microphone and the filtered electrical input signal provided to said speaker module and, in response to the at least one difference provide a control signal to the filter to control the filter.

Abstract: The disclosure provides a loudspeaker apparatus and a method of driving the acoustic transducers by predicting and compensating a physical phenomenon of acoustic pressure changes within an enclosure caused by at least one of the acoustic transducers. The loudspeaker apparatus includes an enclosure having an inner space, a first acoustic transducer, a second acoustic transducer, and a controller. The first and second acoustic transducers are mounted on the enclosure and share the same inner space of the enclosure, such as sound bar and the likes. For the operation of the loudspeaker apparatus, the controller applies an algorithm or mathematical model (e.g., transfer function) to an audio signal received from an external source, so that the sound respectively outputted by the first and second acoustic transducers sharing the same inner space may be compensated as if the first and second acoustic transducers are individually mounted on its own enclosure.

Abstract: A vibration diaphragm and a manufacturing method thereof are provided. The vibration diaphragm comprises an annular support member, a first vibration diaphragm layer and a circuit layer. The first vibration diaphragm layer is fixedly connected to a support body of the annular support member. The circuit layer is positioned on a surface of the first vibration diaphragm layer that is adjacent to a vibrating voice coil and is fixedly connected to the first vibration diaphragm layer and the support body. The circuit layer is provided with a circuit area, a capacitance area, and a capacitance solder pad. The capacitance area is a capacitance electrode plate formed on the first vibration diaphragm layer. The capacitance area is communicated with the capacitance solder pad by means of the circuit area. The solder pad corresponds to the support body. The reliability of capacitance data acquisition is improved.

Abstract: An acoustic pressure reducer acoustically couples to and provides acoustic impedance to attenuate the acoustic box pressure of an acoustic system, such as a loudspeaker system. The pressure reducer may also allow an ambient pressure of the acoustic system to equalize with an ambient pressure of an external environment and the ambient pressure of the acoustic pressure reducer at a certain rate. The attenuation may allow for inexpensive acoustic sensors to be utilized within the pressure reducer to measure one or more acoustic properties of an attenuated acoustic pressure within the pressure reducer. An unattenuated acoustic pressure value of the acoustic system may be estimated using a known transfer function of the pressure reducer and the attenuated acoustic pressure values measured within. A controller coupled to the acoustic system may adjust one or more operating characteristics in response to estimating the unattenuated acoustic pressure.

Abstract: An audio system comprises an audio driver configured to receive a target audio signal and a feedback signal and to generate an adjusted audio signal responsive to the target audio signal and the feedback signal. A loudspeaker is configured to convert the adjusted audio signal into acoustical sound. A test signal generator is configured to generate a test signal having a higher frequency than the target audio signal. The test signal causes a test current to flow through the loudspeaker. A current sensing circuit is configured to measure the test current flowing through the loudspeaker and to generate a current sense signal indicative of the test current. A feedback circuit is configured generates the feedback signal responsive to the current sense signal.

Abstract: Membrane device comprising a support, a membrane suspended on the support, a first actuator in contact with the membrane designed to apply a force on the membrane, a second actuator in contact with the membrane designed to apply a force on the membrane, means of determining the position of the membrane relative to the support and control means of the first and second actuators, said control means applying a deformation signal to one of the first and second actuators to deform the membrane and applying a control signal to the other of the first and second actuators to control displacement of the membrane, application of the control signal being determined by the membrane position.

Abstract: A system is disclosed which allows for canceling high frequency rail to rail common mode swing at pulse-width modulation (PWM) frequency for a Class-D, H and G audio amplifier or a Linear Resonance Actuator (LRA) driver. This allows wide bandwidth current sensing without the need of external components, or large on-chip resistor-capacitor (RC) networks, facilitating integration of the sense resistor. In addition, the sense amplifier DC input common mode and audio band common mode swing is reduced, allowing a sense resistor high frequency common mode swing of a least twice the MOSFET gate break down voltages.

Abstract: A voice coil motor controller configured to determine a voltage across and a current through a voice coil motor having an input signal supplied thereto and determine its impedance therefrom, the controller further configured to identify asymmetry in variations of said impedance over time to determine an asymmetry value, the controller further configured to provide for control of said voice coil motor using said asymmetry value.

Abstract: A driving apparatus includes a power amplifier that supplies a driving signal to a vibrator, a current detector that outputs a detection signal corresponding to a driving current of the vibrator, and a driving controller that positively feedback a signal based on the detection signal to the power amplifier. The driving controller includes an A/D converter that A/D converts the detection signal, a first processing section that applies a gain compensation and compressor processes to an output digital signal of the A/D converter, a second processing section that performs a process of adding a digital signal corresponding to an input signal of the driving apparatus to an output digital signal of the first processing section, and a D/A converter that D/A converts an output digital signal of the second processing section to produce an analog signal supplied to the power amplifier.

Abstract: A position sensor system is useful for monitoring positions of shifters in transmissions and other applications. The position sensing system has an array of magneto resistive sensors and a controller configured to determine a position of a magnet along a path by triangulation. Some embodiments are relatively insensitive to fluctuations in a distance between the sensors and the path. Also described is an actuating assembly comprising a movable cylinder and a fixed rod. The actuating assembly may be applied for moving synchronizers or the like in power transmissions.

Abstract: A loudspeaker controller (1) for controlling a loudspeaker (2), configured to determine time-varying impedance information of the loudspeaker (2) based on a loudspeaker voltage and a measure of a loudspeaker current and provide for control of the loudspeaker (2) in accordance with said time-varying impedance information.

Abstract: Method and apparatus for entrainment containment in digital filters using output phase modulation. Phase change is gradually introduced into the acoustic feedback canceller loop to avoid entrainment of the feedback canceller filter. Various embodiments employing different output phase modulation approaches are set forth and time and frequency domain examples are provided. Additional method and apparatus can be found in the specification and as provided by the attached claims and their equivalents.

Abstract: A circuit for conditioning an acoustic transducer driving signal includes an inner feedback circuit having a test signal input for receiving a test signal, a feedback input for receiving a feedback signal, circuitry for forming an output signal including circuitry for amplifying the input signal according to the feedback signal, and an output for providing the output signal. The circuit also includes an outer feedback circuit having a signal input for receiving the output signal from the inner feedback circuit, a desired offset input for receiving a signal representative of a desired output offset, a first low-pass filter circuit for detecting an actual offset in the output signal, signal combination circuitry for forming the feedback signal including combining the actual offset with the desired output offset, and a feedback output for providing the feedback signal to the feedback input of the inner feedback circuit.

Abstract: In an example embodiment, an apparatus includes an enclosure having a loudspeaker mounted therein. The apparatus also includes an IC package mounted inside the enclosure. The IC package includes an amplifier configured to amplify an input audio signal, received at an input of the amplifier, to produce a drive signal. The amplifier is configured to drive the loudspeaker with the drive signal via an output of the amplifier. The IC package also includes a pressure sensor configured to output a status signal, indicative of a sound pressure level inside the enclosure, from an output terminal of the pressure sensor. The apparatus also includes an audio processing circuit connected to the amplifier and configured to adjust strength of the drive signal produced by the amplifier, as a function of the sound pressure level indicated by the status signal.

Abstract: A mass port configured to tune a frequency response of an audio reproduction device is disclosed. The mass port includes a head portion and an insertion portion coupled to the head portion. The head portion includes a sealing structure on a rear side. The head portion is configured to attach to a rear plate of a driver at the sealing structure. The insertion portion is configured to be inserted into a speaker port on the rear plate of the driver. The head portion and the insertion portion include an air slot that runs through the head portion and the insertion portion.

Abstract: A portable electronic device has an acoustic port having an aperture in a housing having a speaker and pressure sensing transducer incorporated therein. During normal use of the portable electronic device, the aperture of the acoustic port may become obstructed during handling, holstering or surface placement, resulting in reduced sound quality and a waste of energy from a battery powering the device. The pressure sensing transducer detects an obstruction of the acoustic port by detecting an increase in acoustic pressure within the housing or within an acoustic chamber coupling the aperture of the acoustic port to the speaker. In response, acoustic characteristics of the obstructed port speaker's audio are altered to conserve power or enhance audio. Furthermore, acoustic characteristics of speakers of unobstructed acoustic port apertures of the device may also be altered in response to detection of the obstruction.

Abstract: Embodiments for estimating nonlinear distortion and for tuning parameter(s) for boosting sounds are described. A test signal including at least two simultaneous audible tones is generated. One tone is a fundamental tone and others are harmonics of the fundamental tone. The ratio of the number of nonlinear distortion products not coincident with the frequencies of the tones to the number of all the products is, as an example, greater than 0.80. A spectral analysis is performed on the response of a loudspeaker to the test signal. A nonlinear distortion value is estimated by regarding the energy at harmonic frequencies of the fundamental tone signal but not at the frequencies of the tone signals as contribution from the nonlinear distortion. A subjectively correlated measure of nonlinear distortion is obtained for tuning a parameter for boosting low frequency outputs of one or more loudspeakers.

Abstract: This disclosure describes an audio video distribution system that uses a local area network to distribute a digital audio signal and that uses multiple network speaker nodes to broadcast the digital audio in a multi speaker session. The system includes a local area network that distributes the digital audio signal for the audio video distribution system. In addition, the system includes a first network speaker node participating in a multi speaker session and performing in a master mode, and where the first network speaker node calculates, originates, and controls a distributed multi session clock that is distributed over the network. The system further includes one or more additional network speaker nodes participating in the multi speaker session and perform in a slave mode, and where the additional network speaker nodes receive the distributed multi session clock from the first speaker node.

Abstract: A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to measure the output of the transducer in order to control the adaptation of the anti-noise signal and to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit that performs the adaptive noise canceling (ANC) function also detects frequency-dependent characteristics in and/or direction of the ambient sounds and alters adaptation of the noise canceling circuit in response to the detection.

Abstract: An apparatus including a diaphragm, where the diaphragm includes a membrane having electrically conductive material; a drive configured to move the diaphragm; and a connector configured to connect the membrane to a ground.

Abstract: An audio system comprises an audio driver configured to receive a target audio signal and a feedback signal and to generate an adjusted audio signal responsive to the target audio signal and the feedback signal. A loudspeaker is configured to convert the adjusted audio signal into acoustical sound. A test signal generator is configured to generate a test signal having a higher frequency than the target audio signal. The test signal causes a test current to flow through the loudspeaker. A current sensing circuit is configured to measure the test current flowing through the loudspeaker and to generate a current sense signal indicative of the test current. A feedback circuit is configured generates the feedback signal responsive to the current sense signal.

Abstract: [Object] To provide an induced signal removing circuit that feeds back induced voltage regarded as electrical signals into the input side of an inductive load to remove the induced voltage from the metal part, the induced voltage appearing even across an insulated metal part in response to signals input to the inductive load.

Abstract: An audio output device includes a housing, a speaker, a switching unit, a fixing component and a control unit. An opening is formed on the housing. The speaker is for outputting sound. The switching unit is installed inside the housing. The fixing component is fixed in the opening of the housing for triggering the switching unit so that the switching unit outputs a switching signal. The control unit is electrically connected to the switching unit and the speaker, and the control unit controls the speaker to output sound in a corresponding sound field as the control unit receives the switching signal.

Abstract: There is disclosed methods and apparatus for decomposing a signal having a plurality of channels into direct and diffuse components. The correlation coefficient between each pair of signals from the plurality of signals may be estimated. A linear system of equations relating the estimated correlation coefficients and direct energy fractions of each of the plurality of channels may be constructed. The linear system may be solved to estimate the direct energy fractions. A direct component output signal and a diffuse component output signal may be generated based in part on the direct energy fractions.

Abstract: A method of measuring an impulse response of an amplifier coupled in operation to a loudspeaker arrangement includes: (a) coupling directly to a connection between the amplifier and the loudspeaker arrangement for obtaining access to a drive signal (Samp) applied to the loudspeaker arrangement to generate an acoustic output (S2); (b) disposing a microphone arrangement for receiving the acoustic output (S2) of the loudspeaker arrangement; (c) using a test signal generator to apply a test signal (Ssw) to an input of the amplifier; and (d) receiving at a digital signal processing arrangement (DSP, 210) at least the drive signal (Samp) and the acoustic output (S2) corresponding to the test signal (Ssw) and performing on these signals a signal processing operation for determining an impulse response for at least one of: the amplifier, the loudspeaker arrangement.

Abstract: A control method of sound producing, sound producing apparatus, and portable apparatus are provided. The control method of sound producing is for a portable device, including the following steps. (a) A first detected parameter indicating a detected excursion of a speaker of the portable device is generated. (b) A second audio signal is generated based on a first audio signal, wherein the second audio signal is generated selectively by compensation according to at least the first detected parameter. (c) A gain value is determined according to at least the first detected parameter and a third audio signal is generated based on the second audio signal according to the gain value.

Abstract: The present invention provides a loudspeaker with a port tube having an acoustic leakage path through a motile part thereof. In this way, excess energy caused by longitudinal resonance at higher frequencies is radiated transversely through the port tube walls rather than contributing to the output of the loudspeaker itself.

Abstract: Provided are an audio signal processing apparatus and method. The audio signal processing apparatus includes: a sensing unit for sensing an impedance value of a headphone and adjusting a gain to be applied to an audio signal based on the sensed impedance value; and an amplifier for generating an output audio signal by receiving at least one bias voltage corresponding to the adjusted gain and amplifying the input audio signal according to the adjusted gain. The audio signal processing apparatus is capable of appropriately adjusting the magnitude of an acoustic signal output from a headphone, according to the product specifications of the headphone.

Abstract: A vehicle sound system includes a subwoofer system having a subwoofer, a satellite amplifier for driving the subwoofer, a host amplifier for receiving an audio signal, a noise management processing unit for providing, to the host amplifier, information to be used for achieving a desired audio environment, a sensor for providing information to the noise management processing unit concerning the ambient audio environment, a control line between the satellite amplifier and the host amplifier for transmission of control signals to the satellite amplifier, and a signal line between the satellite amplifier and the host amplifier for transmission of audio signals to the satellite amplifier, the satellite controller being configured to cause a diagnostic signal to be placed on the control line, the diagnostic signal being indicative of an operating condition of the subwoofer system.

Abstract: A signal processor including an equalizer responsive to an input signal and to a parameter signal, said equalizer configured to provide an output signal to an electro-acoustical transducer for compensating a frequency response of said electro-acoustical transducer; a transducer element for monitoring at least a physical parameter of said electro-acoustical transducer, said transducer element configured to provide a transducer signal, a processor block responsive to said transducer signal, configured to provide said parameter signal.

Abstract: A sound determination apparatus receives acoustic signals by a plurality of sound receiving units, and generates frames having a predetermined time length. The sound determination apparatus performs FFT on the acoustic signals in frame units, and converts the acoustic signals to a phase spectrum and amplitude spectrum, which are signals on a frequency axis, then calculates the difference at each frequency between the respective acoustic signals as a phase difference, and selects frequencies to be the target of processing. The sound determination apparatus calculates the percentage of frequencies at which the absolute values of the phase differences of the selected frequencies are equal to or greater than a first threshold value, and determines that the acoustic signal coming from the nearest sound source is included in the frame when the calculated percentage is equal to or less than a second threshold value.