Founded in 1968 by Patrick Howe Quilter as Quilter Sound Company (later shortened to QSC), QSC, LLC is an American manufacturer of professional audio, video, and control products headquartered in Costa Mesa, California. Operating from an 81,000 square foot manufacturing facility, the company employs 600+ people globally and generates $535M in annual revenue. QSC specializes in amplifiers, loudspeakers, cameras, video endpoints, digital signal processors, and the Q-SYS networked audio, video and control platform. A 7-time recipient of Orange County Register's 'Best Place to Work' award, QSC serves live sound reinforcement, house of worship, and commercial audio markets. On January 1, 2025, QSC was acquired by Acuity Brands (NYSE: AYI) for $1.215 billion, becoming part of Acuity Intelligent Spaces division while maintaining operations and product development.