Sound Mixer Walt Martin, who often worked on director Clint Eastwood’s feature films, died last month. He was 69.

Walt Martin Dies At 69

Martin passed away on July 24 of vasculitis at Providence Saint Joseph Medical Center in Burbank after being hospitalized for chest pains, his wife Elena Martin told The Hollywood Reporter.

Martin first teamed up with Eastwood on 1999 picture True Crime. He went on to work with him on Space Cowboys (2000), Blood Work (2002), Mystic River (2003), Million Dollar Baby (2004), Letters From Iwo Jima (2006), Changeling (2008), Gran Torino (2008), Invictus (2009), Hereafter (2010) and Trouble With the Curve (2012).

Martin also worked with Eastwood on this summer’s Jersey Boys musical and most recently on the Chris Kyle biopic American Sniper starring Bradley Cooper, which is to hit theaters next year. He won an Oscar for sound mixing Eastwood’s 2006 World War II drama Flags of Our Fathers.

Prior to becoming part of Eastwood’s crew, Martin had worked on Last Resort (1986), John Huston’s The Dead (1987), Tremors (1990), Tombstone (1993) and Cold Around the Heart (1997). He also worked on Charlie’s Angels (2000) and The Banger Sisters (2002).

Martin’s recent TV credits include working on The Closer, Sons of Anarchy and Mad Men.

Martin is survived by his wife and step-daughter Claudia.