A seat assembly including: a seat; and a loudspeaker unit, wherein the loudspeaker unit is configured as a subwoofer for producing sound at bass frequencies below 200 Hz, and the loudspeaker unit includes: an array of two or more diaphragms, each diaphragm in the array 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, and wherein one or more of the diaphragms are included in a first subset of the diaphragms and one or more of the diaphragms are included in a second subset of the diaphragms; a plurality of drive units, wherein each drive unit is configured to move a respective one of the diaphragms in the array based on a respective electrical signal; a frame, wherein each diaphragm in the array is suspended from the frame via one or more suspension elements such that the first radiating surfaces are facing in a first direction and the second radiating surfaces are facing in an opposite second direction, wherein the frame is configured to allow sound produced by the first radiating surfaces to propagate out from a first side of the loudspeaker unit in the first direction and to allow sound produced by the second radiating surfaces to propagate out from a second side of the loudspeaker unit in the second direction; drive circuitry (150, 150') configured to provide each drive unit with a respective electrical signal derived from an audio source (156, 156') such that the electrical signal(s) provided to the one or more drive units configured to move the first subset of diaphragms is/are out of phase with respect to the electrical signal(s) provided to the one or more drive units configured to move the second subset of diaphragms; wherein the loudspeaker unit is mounted within a headrest of the seat. a seat; and a loudspeaker unit, wherein the loudspeaker unit is configured as a subwoofer for producing sound at bass frequencies below 200 Hz, and the loudspeaker unit includes: an array of two or more diaphragms, each diaphragm in the array 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, and wherein one or more of the diaphragms are included in a first subset of the diaphragms and one or more of the diaphragms are included in a second subset of the diaphragms; a plurality of drive units, wherein each drive unit is configured to move a respective one of the diaphragms in the array based on a respective electrical signal; a frame, wherein each diaphragm in the array is suspended from the frame via one or more suspension elements such that the first radiating surfaces are facing in a first direction and the second radiating surfaces are facing in an opposite second direction, wherein the frame is configured to allow sound produced by the first radiating surfaces to propagate out from a first side of the loudspeaker unit in the first direction and to allow sound produced by the second radiating surfaces to propagate out from a second side of the loudspeaker unit in the second direction; drive circuitry (150, 150') configured to provide each drive unit with a respective electrical signal derived from an audio source (156, 156') such that the electrical signal(s) provided to the one or more drive units configured to move the first subset of diaphragms is/are out of phase with respect to the electrical signal(s) provided to the one or more drive units configured to move the second subset of diaphragms; wherein the loudspeaker unit is mounted within a headrest of the seat. an array of two or more diaphragms, each diaphragm in the array 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, and wherein one or more of the diaphragms are included in a first subset of the diaphragms and one or more of the diaphragms are included in a second subset of the diaphragms; a plurality of drive units, wherein each drive unit is configured to move a respective one of the diaphragms in the array based on a respective electrical signal; a frame, wherein each diaphragm in the array is suspended from the frame via one or more suspension elements such that the first radiating surfaces are facing in a first direction and the second radiating surfaces are facing in an opposite second direction, wherein the frame is configured to allow sound produced by the first radiating surfaces to propagate out from a first side of the loudspeaker unit in the first direction and to allow sound produced by the second radiating surfaces to propagate out from a second side of the loudspeaker unit in the second direction; drive circuitry (150, 150') configured to provide each drive unit with a respective electrical signal derived from an audio source (156, 156') such that the electrical signal(s) provided to the one or more drive units configured to move the first subset of diaphragms is/are out of phase with respect to the electrical signal(s) provided to the one or more drive units configured to move the second subset of diaphragms; wherein the loudspeaker unit is mounted within a headrest of the seat.