The following project uses a modular structure to connect subwoofers to speakers without showing the cable that connects them, since it is not very aesthetic to be left in sight. To fulfill this request I was inspired by the design of Shiro Kuramata and his idea of transparency obtained with the use of perforated or glassy metal materials. The project in question consists in the realization of modular wall bookcases, whose columns and shelves function as corridors to accommodate connecting cables. The perforated structure of the columns also allows the interlocking of special uprights for fixing the shelves.