A seat assembly that includes: a headrest; a seat portion; a loudspeaker that includes: 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 based on an electrical signal; and a loudspeaker support structure , wherein the diaphragm is suspended from the loudspeaker support structure via one or more loudspeaker suspension elements ; wherein the loudspeaker support structure encloses a volume configured to receive sound produced by the second radiating surface, wherein the loudspeaker support structure includes one or more regions of porous material having a specific airflow resistance in the range 300-5000Pa.s/m, wherein the surface area of the one or more regions of porous material is at least 80% of the effective radiating area of the diaphragm SD; wherein the one or more regions of porous material are configured to allow sound produced by the second radiating surface to exit the volume enclosed by the loudspeaker support structure via the one or more regions of porous material; wherein the loudspeaker is mounted in the headrest of the seat assembly such that sound produced by the first and second radiating surfaces of the loudspeaker is allowed to propagate out of the seat assembly via open or acoustically transparent portions of the seat assembly, and such that an ear of a user is located at a listening position that is 50cm or less from the first radiating surface of the diaphragm when the user is sat in a seat portion of the seat assembly. a headrest; a seat portion; a loudspeaker that includes: 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 based on an electrical signal; and a loudspeaker support structure , wherein the diaphragm is suspended from the loudspeaker support structure via one or more loudspeaker suspension elements ; 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 based on an electrical signal; and a loudspeaker support structure , wherein the diaphragm is suspended from the loudspeaker support structure via one or more loudspeaker suspension elements ; wherein the loudspeaker support structure encloses a volume configured to receive sound produced by the second radiating surface, wherein the loudspeaker support structure includes one or more regions of porous material having a specific airflow resistance in the range 300-5000Pa.s/m, wherein the surface area of the one or more regions of porous material is at least 80% of the effective radiating area of the diaphragm SD; wherein the one or more regions of porous material are configured to allow sound produced by the second radiating surface to exit the volume enclosed by the loudspeaker support structure via the one or more regions of porous material; wherein the loudspeaker is mounted in the headrest of the seat assembly such that sound produced by the first and second radiating surfaces of the loudspeaker is allowed to propagate out of the seat assembly via open or acoustically transparent portions of the seat assembly, and such that an ear of a user is located at a listening position that is 50cm or less from the first radiating surface of the diaphragm when the user is sat in a seat portion of the seat assembly. <EOS>