Homepage - Radian Audio Radian Audio Engineering, Inc., was founded in 1988, with the mission of manufacturing high-quality loudspeakers in California, USA. Today, Radian Audio is a major player for all application segments Radian Audio Engineering, Inc., was founded in 1988, with the mission of manufacturing high-quality loudspeakers in California, USA. Today, Radian Audio is a major player for all application segments of the OEM loudspeaker component business.