Speaker unit

A speaker unit in which an open end of each of acoustic tubes is disposed on an upper surface of a casing is produced. The speaker unit is mounted outside a seat, for example, to an upper position of a backface side of a backrest of the seat via a connecting member or the like. Thereby, the open ends of the acoustic tubes are disposed at a position near both ears of a seated person. Since low-frequency sound can be reproduced to an area near both the ears of the seated person, so much output sound pressure level of the drive speaker is not needed. Therefore, a drive speaker of a small bore diameter can be applied to the speaker unit, and the speaker unit itself can be made compact and light. The speaker unit is mounted on the backface side of the backrest of the seat, for example, and it is not necessary to take the trouble to ensure a place for placing the speaker unit around the seat. Accordingly, for example, when the speaker unit is mounted outside the seat of a vehicle, a narrow space inside the vehicle can be utilized effectively.