Have you used Bink volume commands in your projects? Let me know in the comments.

binksetvolume myvideo.bik @12 After running, the tool modifies the Bink file’s internal audio gain—no re-compression needed. Check your tool’s documentation to confirm whether the value is a percentage, multiplier, or dB.

Understanding binksetvolume@12 : A Quick Guide to Volume Control in Bink Video