How do you mix background audio with narration clearly?

How do you mix background audio with narration clearly?

Background audio should support the narration. A technically valid mix can still be difficult to understand if music competes with speech.

Build the mix deliberately

Use audio you have permission to include. Set narration as the main reference and reduce background level where necessary. Inspect starts, endings, and transitions between segments. Check for clipping and abrupt changes instead of relying on one volume multiplier for every source file.

Review the exported result

Listen on representative devices at normal volume. Processing tools can adjust loudness, fades, and mixing, but no single setting guarantees clarity for every recording. Confirm that the final encode contains the intended audio streams and does not truncate the narration. Keep the unmixed sources so a level adjustment does not require generating speech again. Test a quiet sentence over a loud musical section to expose the difficult case.

Further reading: FFmpeg audio filters.