The final sequence where Jake LaMotta is in front of his mirror was filmed on the last day of shooting, requiring 19 takes, with only the 13th being used for the film. Scorsese wanted to have an atmosphere that would be so cold that the words would have an impact as he tries to come to terms with his relationship with his brother. A sound mix arranged by Frank Warner was a delicate process taking six months. According to Scorsese, the sound on "Raging Bull" was difficult because each punch, camera shot, and flash bulb would be different. Also, there was the issue of trying to balance the quality between scenes featuring dialogue and those involving boxing (which were done in Dolby Stereo). "Raging Bull" went through a test screening in front of a small audience including the chief executives of United Artists, Steven Bach and Andy Albeck. The screening was shown at the MGM screening room in New York around July 1980. Later, Albeck praised Scorsese by calling him a "true artist".