the fall-preventing member fixed to a beam or the like disposed above the ceiling and extending from the beam is engaged with the speaker unit by being passed through or hooked on a mounting member (engaged member) fixed or fastened to the cabinet section. Then, the speaker unit is inserted into the mounting hole and fixed by means of fastening members, such as bolts. Thus, even in case a human operator erroneously releases its (his or her) hand, supporting the speaker unit, from the speaker unit during a mounting operation, the fall-preventing member (e.g., chain) can prevent the speaker unit from falling down. Similarly, when, in a dismounting operation, the speaker unit is pulled out from the mounting hole of the ceiling after cancellation of the fastening bythe fastening members (bolts), the fall-preventing member can prevent the speaker unit from falling down.
However, with the conventionally-known known speaker-unit-fall-preventing structure, the human operator has to perform the operation for engaging the fall-preventing member with the mounting member (engaged member) of the speaker unit with one hand while supporting or holding the speaker unit with the other hand. Because the operation for engaging the fall-preventing member with the mounting member of the speaker unit is performed near the ceiling, the human operator lifts the speaker unit up to the position of the mounting hole of the ceiling while standing on a stepladder. But, because the conventionally-known speaker unit does not have a particular section or component part with which the human operator can hold the speaker unit with