THX is an American based company headquartered in San Francisco, California. The company's purpose is to create "high fidelity" audio for surround sound theaters and other uses. In 2016, the company was acquired by Razer Incorporated. THX was formerly a subsidiary of Creative Technology Limited (2002-2016), and originally Lucasfilm (1983-2002).
THX's services are often used in Pixar feature length films, typically for theatrical use.