Metallica completed the final overdubs and mixing for The Black Album at A&M Studios in Hollywood. These finishing sessions took place in June and July 1991.
Most of the album’s main recording had occurred at One on One Recording Studios in Los Angeles, with roughly a week spent at Little Mountain Sound Studios in Vancouver. Separating the principal recording from the final overdubs and mixing is important because accounts often refer generally to “recording in Los Angeles” and omit the later studio change.
The finishing stage was crucial to the album’s polished sound. Producer Bob Rock and the band had to balance heavy guitars, prominent drums, vocals, and a more audible bass presence. “Enter Sandman” was mixed first, and the process helped establish the sonic template for the rest of the record.
A&M Studios was located in Hollywood and had a long history in popular music. For Metallica, its role came at the end of an unusually demanding production period that began in October 1990.