Abstract: A method and apparatus for adjusting a cross-over frequency of a loudspeaker system. The loudspeaker system includes at least a first loudspeaker for frequencies below the cross-over frequency and a second loudspeaker for frequencies above the cross-over frequency. A level of the first loudspeaker is matched with the second loudspeaker using a first test signal and a room response is compensated in the loudspeaker system on the basis of the first test signal. The compensated room response is measured using a second test signal. A maximum frequency for the first loudspeaker and a minimum frequency for the second loudspeaker are determined. A cross-over frequency that results in a minimum cumulative total harmonic distortion energy at one or more sound pressure levels is searched between the minimum and maximum frequency.

Abstract: A method and apparatus for adjusting a cross-over frequency of a loudspeaker system. The loudspeaker system includes at least a first loudspeaker for frequencies below the cross-over frequency and a second loudspeaker for frequencies above the cross-over frequency. A level of the first loudspeaker is matched with the second loudspeaker using a first test signal and a room response is compensated in the loudspeaker system on the basis of the first test signal. The room response is measured using a second test signal. A maximum frequency for the first loudspeaker and a minimum frequency for the second loudspeaker are determined. A cross-over frequency that results in a minimum cumulative total harmonic distortion energy at one or more sound pressure levels is searched between the minimum and maximum frequency.

Abstract: A system for adjusting a response of a loudspeaker system. The system includes a woofer installed in a housing. The woofer includes a woofer cone. A transmitter for transmitting an ultrasonic audio signal towards the woofer cone. A receiver for receiving the ultrasonic audio signal. A detection unit for determining the position of the woofer cone on the basis of a difference between the phase of the reflected ultrasonic audio signal with respect to the ultrasonic audio signal transmitted from the transmitter. A control unit for adjusting a spring constant of the membrane of the loudspeaker system on the basis of the determined position. A method for adjusting a response of a loudspeaker system, to a module to be used in the system. A computer program product including computer code for adjusting a response of the loudspeaker system.

Abstract: Object tracking using ultrasonic signals. A receiver receives a signal transmitted from a transmitter. The receiver uses at least two receiving elements for forming at least two analysis signals on the basis of the received signal. The receiver includes a detector, such as a phase detector, which examines the analysis signals and forms an indication on a difference between the analysis signals. The indication is, for example, indicative of a phase difference between the analysis signals. The transmitted signal is a modulated ultrasonic signal, wherein the receiver demodulates the signal to recover the modulating signal. The indication can be used to determine a heading angle information of the object to be tracked. The heading angle information may be a direction of the object with respect to the transmitter. The heading angle information can be used to make e.g. a corrective action to audio signals to be formed for listening.

Abstract: A system for adjusting a response of a loudspeaker system. The system includes a woofer installed in a housing. The woofer includes a woofer cone. A transmitter for transmitting an ultrasonic audio signal towards the woofer cone. A receiver for receiving the ultrasonic audio signal. A detection unit for determining the position of the woofer cone on the basis of a difference between the phase of the reflected ultrasonic audio signal with respect to the ultrasonic audio signal transmitted from the transmitter. A control unit for adjusting a spring constant of the membrane of the loudspeaker system on the basis of the determined position. A method for adjusting a response of a loudspeaker system, to a module to be used in the system. A computer program product including computer code for adjusting a response of the loudspeaker system.

Abstract: Object tracking using ultrasonic signals. A receiver receives a signal transmitted from a transmitter. The receiver uses at least two receiving elements for forming at least two analysis signals on the basis of the received signal. The receiver includes a detector, such as a phase detector, which examines the analysis signals and forms an indication on a difference between the analysis signals. The indication is, for example, indicative of a phase difference between the analysis signals. The transmitted signal is a modulated ultrasonic signal, wherein the receiver demodulates the signal to recover the modulating signal. The indication can be used to determine a heading angle information of the object to be tracked. The heading angle information may be a direction of the object with respect to the transmitter. The heading angle information can be used to make e.g. a corrective action to audio signals to be formed for listening.