Formosa Hi-Fi occupies a long-closed underground gallery beneath the Viaduto do Chá, which is a more interesting setting than another dark bar with records in the corner. The sound system was designed for a large, irregular room: more than 20 speakers create small left-right stereo zones across the tables instead of leaving half the crowd with one channel.
The bar was built as a room inside the protected gallery, with its own acoustic panels and walls. Its collection runs past 6,000 records and CDs, moving through classical music, jazz, blues, dub, reggae, and classic rock. There is food, drinks, and a crowd large enough to make the room lively, but the system is doing serious work underneath it all.
Find a table in one of the stereo zones and give the room a few tracks. Formosa is a social listening bar on a larger scale, not a small kissa transplanted to São Paulo.