What is "proac"

ProAc Limited is a British loudspeaker manufacturing company. The company was reportedly founded by Stewart Tyler in 1979 and registered on 09/05/1988. The brand of ProAc was built on the reputation of his first loudspeaker manufacturing entity, Celef Audio Ltd., which was reportedly founded in 1973, incorporated on 10/09/1975 and renamed to Celef Audio International Limited on 10/12/1985. The Celef name is no longer used for marketing, but still appears to remain the legal and financial entity operating the ProAc brand.