The use of -9 dB in audio production depends on the context and specific requirements. Here are some common use cases and reasons why -9 dB is used as a level:
Broadcasting and Loudness Standards: In broadcasting, specific loudness standards such as EBU R128 (Europe) or ATSC A/85 (USA) are applied.
Mastering in Music Production: During mastering, some producers aim for -9 dB as a target loudness level.
Film and Television: In film production, there is often much greater dynamic range than in music productions.
Gaming and Interactive Media: In audio production for games, -9 dB is sometimes used as a reference level.
Live Sound and PA Systems: Live technicians may use -9 dB as a target level.
Conclusion: -9 dB is used to provide headroom, particularly in professional applications with large dynamic ranges.