Bob Katz is an audio mastering engineer and author of a popular book on audio mastering. Katz has mastered three Grammy Award-winning albums and one nominated album. He has received acclaim from audiophiles and his book on mastering has received acclaim, with some considering it the "definitive work on mastering". He has developed proprietary systems K-Stereo and K-Surround. These processes are designed to "recover lost or amplify hidden ambience, space and imaging, and generate stereo from mono signals without adding artificial reverberation."