The BS-678B, whose cabinet is made of wood, can be installed in portrait or landscape orientation. Both hidden cables in the wall and exposed cables can be used for the speaker cable connection. The speaker structure that allows direct wall mounting with screws prevents the speaker from falling easily even if an outward force is applied. The input impedance can be easily changed by changing the tap position of the transformer. Two built-in 6-inch dual-cone speaker units provide high-quality sound. The push-in type input connector facilitates the connection of cables and allows the wiring of jumpers.