CPC H04R 1/2819 (2013.01) [H04R 1/028 (2013.01); H04R 1/06 (2013.01); H04R 1/288 (2013.01); H04R 7/04 (2013.01); H04R 7/06 (2013.01); H04R 7/18 (2013.01); H04R 9/06 (2013.01); H04R 2307/00 (2013.01); H04R 2400/11 (2013.01)] | 14 Claims |
1. A dipole loudspeaker for producing sound at bass frequencies, the dipole loudspeaker including:
a diaphragm having a first radiating surface and a second radiating surface, wherein the first radiating surface and the second radiating surface are located on opposite faces of the diaphragm;
a drive unit configured to move the diaphragm at bass frequencies such that the first and second radiating surfaces produce sound at bass frequencies, wherein the sound produced by the first radiating surface is in antiphase with sound produced by the second radiating surface;
a frame, wherein the diaphragm is suspended from the frame via one or more suspension elements, wherein the frame is configured to allow sound produced by the first radiating surface to propagate out from a first side of the dipole loudspeaker and to allow sound produced by the second radiating surface to propagate out from a second side of the dipole loudspeaker;
wherein the diaphragm includes a region of porous material having a specific airflow resistance in the range 50-500 Pa·s/m, wherein the diaphragm is configured to permit airflow through at least part of said region of porous material from the first radiating surface of the diaphragm to the second radiating surface of the diaphragm.
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