A seat assembly including: a seat for seating a user; a loudspeaker for producing sound at bass frequencies, the 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 along a movement axis 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 ; and a drive unit frame , wherein the diaphragm is suspended from the drive unit frame via at least one drive unit suspension ; the seat assembly further including a mounting frame , wherein the drive unit frame is suspended from the mounting frame via a mounting frame suspension system that includes at least one mounting frame suspension; the seat assembly being characterised by further including an adjustment mechanism configured to adjust the mounting frame suspension system so as to change the extent to which vibrations generated by the loudspeaker reach the mounting frame via the mounting frame suspension system when the loudspeaker is in use; and a control interface configured to control the adjustment mechanism so as to adjust the mounting frame suspension system based on user input at the control interface. a seat for seating a user; a loudspeaker for producing sound at bass frequencies, the 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 along a movement axis 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 ; and a drive unit frame , wherein the diaphragm is suspended from the drive unit frame via at least one drive unit suspension ; the seat assembly further 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 along a movement axis 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 ; and a drive unit frame , wherein the diaphragm is suspended from the drive unit frame via at least one drive unit suspension ; the seat assembly further including a mounting frame , wherein the drive unit frame is suspended from the mounting frame via a mounting frame suspension system that includes at least one mounting frame suspension; the seat assembly being characterised by further including an adjustment mechanism configured to adjust the mounting frame suspension system so as to change the extent to which vibrations generated by the loudspeaker reach the mounting frame via the mounting frame suspension system when the loudspeaker is in use; and a control interface configured to control the adjustment mechanism so as to adjust the mounting frame suspension system based on user input at the control interface. <EOS>