Harman Becker Automotive Systems Gmbh

Other

Apple Inc.

Leander Scholz

Markus E Christoph

Gerhard Pfaffinger

Florian Wolf

Georg Spielbauer

Peter Perzlmaier

Peter Perzimaier

A system and method is configured to generate a sound wave field around a listening position in a target loudspeaker-room-microphone system in which a loudspeaker array of K&#x2265;1 groups of loudspeakers is disposed around the listening position, and a microphone array of M&#x2265;1 groups of microphones is disposed at the listening position. The system and method include equalizing filtering with controllable transfer functions in signal paths upstream of the K groups of loudspeakers. The system and method further include controlling with equalization control signals of the controllable transfer functions for equalizing filtering according to an adaptive control algorithm based on error signals and an input signal. The microphone array includes at least two first groups of microphones that are annularly disposed around a listener's head, around or in an artificial head or around or in a rigid sphere.

Sound wave field generation

A system and method for automatically controlling the timbre of a sound signal in a listening room are also disclosed, which include the following: generating an acoustic sound output from an electrical sound signal; measuring the total acoustic sound level in the room and generating an electrical total sound signal representative of the total acoustic sound level in the room, wherein the total acoustic sound comprises the acoustic sound output generated from the electrical sound signal; and adjusting the gain of the electrical sound signal dependent on a room-dependent gain signal, the room-dependent gain signal being determined from reference room data and estimated room data.

Automatic timbre control

A method is provided for optimizing acoustic localization at one or more listening positions in a listening environment such as, but not limited to, a vehicle passenger compartment. The method includes generating a sound field with a group of loudspeakers assigned to at least one of the listening positions, the group of loudspeakers including first and second loudspeakers, where each loudspeaker is connected to a respective audio channel; calculating filter coefficients for a phase equalization filter; configuring a phase response for the phase equalization filter such that binaural phase difference (&#x394;&#x3c6;) at the at least one of the listening positions or a mean binaural phase difference (m&#x394;&#x3c6;) averaged over the listening positions is reduced in a predefined frequency range; and filtering the audio channel connected to the second loudspeaker with the phase equalization filter.

Audio system phase equalization

A loudspeaker overload protection circuit and method receives at a compressor a signal representing the estimated loudspeaker power consumption; receives at the compressor a signal representing the nominal power of the loudspeaker; receives at the compressor an input audio signal from the signal source and supplying with the compressor an output audio signal to the loudspeaker; estimates from the output audio signal, (a) signal(s) that represent(s) the voltage and/or current supplied to the loudspeaker and a parameter that represents the ohmic resistance of the loudspeaker the power consumed by the loudspeaker; supplies a signal representing the estimated loudspeaker power consumption to the compressor; and attenuates the input audio signal when the signal representing the estimated loudspeaker power consumption exceeds the signal representing the nominal power of the loudspeaker.

Loudspeaker overload protection

A sound reproduction system that is capable of providing at least two separate sound zones in one coherent listening room. In each sound zone, resulting acoustic signals substantially corresponds to a respective audio source signal associated with the same sound zone, and the contribution of audio source signals associated with a different sound zone to the resulting sound signal is minimized.

Generation of individual sound zones within a listening room

The listening room comprises at least one loudspeaker and at least one listening position. The method comprises providing for each loudspeaker, a group delay response to be equalized associated with one pre-defined position within the listening room; calculating filter coefficients for all-pass filter(s) each arranged upstream to one corresponding loudspeaker, the all-pass filter(s) having a transfer characteristic such that the corresponding group delay response(s) match(es) a predefined target group delay response. The filter coefficients have a group delay response being confined by a frequency dependent group delay constraint that defines a frequency dependent interval exponentially decaying with increasing frequency.

Group-delay based bass management

The invention relates to a method for automated tuning of a sound system, the sound system comprising delay lines, equalizing filters, and at least two loudspeakers, the method comprising the steps of reproducing a useful sound signal through the loudspeakers, measuring sound pressure values at least one location, providing a target transfer function for tuning the delay lines and the equalizing filters of the sound system, the target transfer function representing a desired transfer characteristics of the sound system, adjusting the delay of the delay lines, and adjusting amplitude responses of the equalizing filters such, that the actual transfer characteristics of the sound system approximates the target function.

Sound tuning system

An audio system for enhancing localization of sound perceived by a listener in a listening position includes two loudspeakers and a signal processing unit. The loudspeakers are arranged distant from each other and from the listening position. The sound is transmitted from each of the loudspeakers to the listening position according to a respective transfer function. The transfer functions have different phase responses over frequency. The signal processing unit is connected upstream of the loudspeakers and receives two electrical input signals to be radiated as respective sound signals by the two loudspeakers. The signal processing unit includes a phase shifter unit that phase-shifts at least one of the electrical input signals such that a difference in phase responses is constant over a substantial portion of the human audible frequency in a frequency band.

Audio system

A method for an automatic equalization of sound pressure levels in at least one listening location, where the sound pressure is generated by a first and at least a second loudspeaker, comprising supplying an audio signal of a programmable frequency to each loudspeaker, where the audio signal supplied to the second loudspeaker is phase-shifted by a programmable phase shift relative to the audio signal supplied to the first loudspeaker, and where the phase shifts of the audio signals supplied to the other loudspeakers thereby are initially zero or constant; measuring the sound pressure level at each listening location for different phase shifts and for different frequencies; providing a cost function dependent on the sound pressure level; and searching a frequency dependent optimal phase shift that yields an extremum of the cost function, thus obtaining a phase function representing the optimal phase shift as a function of frequency.

Active noise control using bass management and a method for an automatic equalization of sound pressure levels

An automatic sound system equalizer adjusts a sound system to a target sound, where the sound system includes at least two groups of loudspeakers supplied with electrical sound signals to be converted into acoustical sound signals. The equalizer sequentially supplies each group with the respective electrical sound signal; sequentially assesses the deviation of the acoustical sound signal from the target sound for each group of loudspeakers, and adjusts at least two groups of loudspeakers to a relatively small, preferably minimum deviation from the target sound by equalizing the respective electrical sound signals supplied to the groups of loudspeakers.

Sound system equalization

The invention relates to a method for automated tuning of a sound system, the sound system comprising delay lines, equalizing filters, and at least two loudspeakers, the method comprising the steps of reproducing a useful sound signal through the loudspeakers, measuring sound pressure values at at least one location, providing a target transfer function for tuning the delay lines and the equalizing filters of the sound system, the target transfer function representing a desired transfer characteristics of the sound system, adjusting the delay of the delay lines, and adjusting amplitude responses of the equalizing filters such, that the actual transfer characteristics of the sound system approximates the target function.

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Salching, Germany

Leander Scholz