The BS-678B, is made of wood and can be installed in a vertical or horizontal orientation. Either concealed in-wall wiring or exposed wiring can be used for speaker cable connection. The speaker structure that permits direct wall-mounting with screws prevents the speaker from falling easily even if an outward force is applied to. The input impedance can be easily changed by changing the tap position of the transformer. Two built-in 6-inch double cone speaker units deliver high quality sound. The push-in type input connector makes cable connections easy and allows bridge wiring. BS-678B have a built-in attenuator and can be connected to a 2-wire or 3-wire system.