Professional Sound Source PROSS Ltd. was established in november 2003. Today we are dealing with 3 business directions: recording and music production, introducing and offering music instruments, Band agency and reservation. Two of PROSS's active members, Margus Ermast and Kalle Koppel, are proffessional musicians. They have worked with different kinds of music groups like: choirs, rock bands and classical music groups. The third member, Toivo Tähemaa, is a folkmusician with technical background.