Patent ID: 11943578
Assignee: BANG & OLUFSEN A/S
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 15:
16. A method for improving sound quality especially at low frequencies of a loudspeaker device, which method comprises:
providing a loudspeaker device comprising a loudspeaker unit having a diaphragm with a first surface and a second surface, wherein the loudspeaker unit is mounted in an enclosure having an internal cavity such that the first surface of the diaphragm radiates sound energy into surroundings of the enclosure and the second surface of the diaphragm radiates sound energy into the internal cavity of the enclosure, and wherein the internal cavity is acoustically connected to an opening in the enclosure such that sound energy can enter the surroundings of the enclosure through the opening, wherein the acoustic connection takes place through an acoustic element in which the acoustic element is configured such that the acoustic element can block or open the acoustic connection from the internal cavity to the surroundings;
providing activating means configured to block or open said acoustic connection from the internal cavity to the surroundings;
setting a threshold value based on a diaphragm excursion limit of the loudspeaker unit that defines whether the activating means shall block or open the acoustic connection from the internal cavity to the surroundings;
providing means for determining if said threshold value is exceeded;
if the threshold value is not exceeded, placing the acoustic connection in a blocked state; and
if the threshold value is exceeded, placing the acoustic connection in an open state to prevent non-linear distortion of an acoustic output of the loudspeaker device.