St. Croix was a columnist for Mix Magazine with which he collaborated for 18 years, authoring the popular "Fast Lane" column until right up to his death.
He redesigned the interface for the Quantec Room Simulator, and also held dozens of patents worldwide in technologies not associated with audio.
In 1995, St. Croix was the main contributor to the design and development of the PARIS digital audio workstation in conjunction with EMU-Ensoniq.
His mastering theories, based on the interpretation of his RTA technologies, have been extended by others but the same principles of frequency alignment still remain.
St. Croix also reconstructed and restored the soundtracks from the films "Wizard of Oz", "Easter Parade", "Yankee Doodle Dandy" and "Gone with The Wind".