Abstract: Disclosed are methods for selecting auditory signal components for reproduction by means of one or more supplementary sound reproducing transducers, such as loudspeakers, placed between a pair of primary sound reproducing transducers, such as left and right loudspeakers in a stereophonic loudspeaker setup or adjacent loudspeakers in a surround sound loudspeaker setup. Also disclosed are devices for carrying out the above methods and systems of such devices.

Abstract: The present invention relates to methods and systems for determining an equalization filter for one or more loudspeakers provided in an enclosure, such as a listening room or an automobile cabin. A method for determining an equalization filter for one or more loudspeakers provided in an enclosure comprises the steps of providing the one or more loudspeakers with an audio input signal whereby a sound field is generated in the enclosure; determining an acoustic contribution or room gain of the enclosure to the generated sound field; forming a speaker equalization filter as the square root of the ratio between a target acoustic power output and the actual acoustic power output from the loudspeaker driver(s), which actual acoustic power output is calculated as the square of the power averaged sound pressure divided by the room gain; and determining the equalization filter as the speaker equalization filter.

Abstract: A method and apparatus for having a user select from simultaneously provided audio tracks which are provided from different directions to the user. One of the tracks is provided from in front of the user and with a higher intensity than another track which is provided from a direction more to the side of the user. When the other track is selected, it is provided from in front of the user with a higher intensity, and a third track is now provided from the side of the user and at a lower intensity.

Abstract: A method and a system for adapting the timbre of sound output at power-up/down of a media player or stereo, where the timbre adaptation is a limitation of the bandwidth of the signal or sound, which bandwidth limitation is reduced over time to eventually provide no filtering at all.

Abstract: The present invention relates to a method for controlling one or more loudspeakers provided in an enclosure, such as a listening room or an automobile cabin, the method comprising the steps of: (i) providing said one or more loudspeakers (2, 3, 4) with an audio input signal (5) whereby a sound field (10) is generated in the enclosure (1), and determining the corresponding acoustic power output APO(f) emitted from the one or more loudspeakers (2, 3, 4) into said enclosure (1); (ii) determining an acoustic contribution or room gain RG(f) of the enclosure (1) to the generated sound field (10); (iii) optionally determining a listening position interface LPI(f) that characterises a listener's ability to receive sound energy from a sound field at the specific place in the sound Field, in which he is located; and (iv) determining a filter characteristic as a function of the acoustic power output, the acoustic contribution or room gain RG(f) of the enclosure to the sound field in the enclosure and optionally the list

Abstract: The present invention relates to a method for selecting auditory signal components for reproduction by means of one or more supplementary sound reproducing transducers, such as loudspeakers, placed between a pair of primary sound reproducing transducers, such as left and right loudspeakers in a stereophonic loudspeaker setup or adjacent loudspeakers in a surround sound loudspeaker setup, the method comprising the steps of (i) specifying azimuth angle range within which one of said supplementary sound reproducing transducers is located or is to be located and a listening direction; (Ii) based on said azimuth angle range and said listening direction, determining left and right interaural level difference limits and left and right interaural time difference limits, respectively; (iii) providing a pair of input signals for said pair of primary sound reproducing transducers; (iv) pre-processing each of said input signals, thereby providing a pair of pre-processed input signals; (v) determining interaural level dif

Abstract: The invention relates to a method and a system for adapting a loudspeaker to a specific listening position relative to the loudspeaker according to which method and system the acoustic power radiated by the loudspeaker is corrected by means of a correction filter inserted in the signal path through the loudspeaker, the response of said correction filter being determined by comparison between the a quantity characterising the radiated acoustic power measured at an actual listening position and a similar quantity measured at a reference listening position. According to a specific embodiment of the invention said characterising quantities are the radiation resistances measured at the actual listening position and the reference listening position respectively.

Abstract: Disclosed is a method for equalizing a first loudspeaker positioned in a room in order to compensate for an influence of the room, the method comprising the steps of 1) measuring a listening position transfer function from electrical input of the first loudspeaker to a sound pressure at a listening position in the room, 2) determining a global transfer function representing a spatial average of sound pressure level in the room generated by the first loudspeaker, 3) determining an upper gain limit as a function of frequency, the upper gain limit being based on an inverse of the global transfer function, 4) determining an equalizing filter based on an inverse of the listening position transfer function, wherein a gain of the equalizing filter is limited to a maximum gain in accordance with the upper gain limit, and 5) equalizing the first loudspeaker according to the equalizing filter.

Abstract: A loudspeaker based on a dipole element (DE) with at least one diaphragm arranged to generate an acoustic dipole signal according to an electric signal, e.g. a dedicated dipole driver such as an Air Motion Transformer or a combination of two monopole drivers, e.g. dome tweeters, mounted back to back close together. An acoustic waveguide (WG) is arranged in relation to the dipole element (DE) such that a surface (S) of the acoustic waveguide (WG) is close to the at least one diaphragm of the dipole element (DE). The acoustic waveguide (WG) extends in both directions of a main axis (MA) of the dipole element (DE), thus serving to guide the acoustic dipole signals away from the dipole element (DE). Preferably, the surface (S1, S2) of the acoustic waveguide (WG) has a general tilt of less than 30° in relation to the main axis (MA). Thereby, a diffuse sound field is provided with only a limited requirement for housing the acoustic waveguide (WG) in the depth dimension.

Abstract: It is known to make the performance of a loudspeaker “environment adaptive” in controlling a filter unit based on a measurement of the velocity/acceleration of the loudspeaker diaphragm and the associated sound pressure in front of the diaphragm, by means of an accelerometer and a microphone, respectively, thereby determining the radiation resistance of the diaphragm. The two sensors have to exhibit a constant transfer function throughout the life time of the loudspeaker, which make them very expensive. With the invention it has been found that the accelerometer can be replaced by another microphone held in a small distance from the diaphragm, and this conditions the possibility of using the same microphone for both measurements, e.g. simply by physically moving the microphone from one position to another. It will then no longer be required to use long-time stable sensors, whereby the price of the sensor equipment can be reduced dramatically. Also alternative arrangements are disclosed.

Abstract: A method and a system for equalizing one or more loudspeaker(s), e.g. a hi-fi system, positioned in a room in order to compensate sound reproduction from the loudspeaker for an influence of the room. The method includes measuring a listening position transfer function (L) from electrical input of the loudspeaker (L1) to a sound pressure at a listening position (LP) in the room. A global transfer function (G) representing a spatial average of sound pressure level in the room generated by the loudspeaker (L1) is determined. This global transfer function (G) can either be determined as an average of two or more transfer functions measured in field points scattered across the room or it can be calculated based on an acoustic power output measured from the loudspeaker (L1) together with data regarding sound absorption properties of the room. An upper gain limit (UGL) as a function of frequency is then determined based on an inverse of the global transfer function (G).

Abstract: It is known to make the performance of a loudspeaker “environment adaptive” in controlling a filter unit based on a measurement of the velocity/acceleration of the loudspeaker diaphragm and the associated sound pressure in front of the diaphragm, by means of an accelerometer and a microphone, respectively, thereby determining the radiation resistance of the diaphragm. The two sensors have to exhibit a constant transfer function throughout the life time of the loudspeaker, which make them very expensive. With the invention it has been found that the accelerometer can be replaced by another microphone held in a small distance from the diaphragm, and this conditions the possibility of using the same microphone for both measurements, e.g. simply by physically moving the microphone from one position to another. It will then no longer be required to use long-time stable sensors, whereby the price of the sensor equipment can be reduced dramatically. Also alternative arrangements are disclosed.