Dipole loudspeaker for producing sound at bass frequencies

A seat assembly including:

• a seat;
• a dipole loudspeaker for producing sound at bass frequencies, the dipole loudspeaker including:
• 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, wherein the first radiating surfaces have a combined surface area of at least 100 cm2, and wherein the second radiating surfaces have a combined surface area of at least 100 cm2;
• a plurality of drive units, wherein each drive unit is configured to move a respective one of the diaphragms in the array at bass frequencies such that the first and second radiating surfaces of the diaphragm produce sound at bass frequencies, wherein the sound produced by the first radiating surfaces is in antiphase with sound produced by the second radiating surfaces;
• a frame, wherein each diaphragm in the array is suspended from the frame via one or more suspension elements, wherein the frame is configured to allow sound produced by the first radiating surfaces to propagate out from a first side of the dipole loudspeaker and to allow sound produced by the second radiating surfaces to propagate out from a second side of the dipole loudspeaker;
• and
• drive circuitry configured to provide each drive unit with a respective electrical signal derived from the same audio source;
• and
• a head tracking unit configured to track head movement of a user sat in the seat;
• wherein the drive circuitry is configured to modify at least one of the electrical signals provided to the drive units based on the tracked head movement so as to compensate for movement of the head of a user sat in the seat.