Bob Ludwig

American mastering and lacquer cutting engineer, born circa 1945 in Savannah, Georgia, USA. Started his career at A&R Studios and later worked at Sterling Sound and Masterdisk, becoming vice-president at both. In 1992 founded Gateway Mastering in Portland, Maine. In July 2023, he announced his retirement and the closure of Gateway Mastering.

As a rule of thumb he is generally credited as "Bob Ludwig" on pop/rock/mainstream releases and as "Robert C. Ludwig" or "Robert Ludwig" on classical releases. His cuts can be recognized by his initials "RL" or block-lettered "rL" (sometimes misread as "ΓL") etched in the runouts