James S. Twerdahl was named president of Marantz, a Chatsworth-based stereo concern acquired last year by Dynascan Corp. He replaced Fred N. Hackendahl, Dynascan's vice president for corporate development, who was interim president. Hackendahl will return to Dynascan's Chicago headquarters.
Marantz was previously run by Joseph and Fred Tushinsky, whose family owned a controlling interest before selling to Dynascan just before year's end.
Twerdahl, 44, was previously president of a Los Angeles-based medical technology company, Fertility & Genetics Research. He has also been president of JBL Inc., and was chief executive of Jensen Sound Laboratories, both in the stereo business.