Making music sound great since 2009 We started Stockholm Mastering in 2009 with one ambition – delivering great sounding masters of the highest quality. Sofia von HageSofia begun her mastering career in 2006. With a highly musical ear and an unrivaled attention for detail, she will take your music to perfection. Thomas EbergerThomas has been mastering records for nearly 20 years. Throw anything at him, and you'll get a great sounding record in return.