I have also set the sounds to +5.0 Db. I am completely deaf in my left ear so +5.0 Db works great for me, and I also never have my in-game music turned on.
To install:
Just drop the file into world_of_tanks/res_mods/0.9.15.1.1/audioww
Preview:
Sorry for the poor gameplay (recording of a replay), I'll see if I can salvage some better footage, but for now this video should be good enough.
Disclaimer:
This mod contains data that is copyright protected. The holder of this copyrighted data is ©NBGI. You take full responsibility and hereby acquit Wargamingand, and the mod authors of any responsibility by downloading this mod. This mod is solely for a fair use non-profit purpose!
Thanks to MajorRenegade for very awesome tutorial & huge shoutout to Abandonedintel on the /r/acecombat subreddit for the work he put into to convert these sound files!
Do NOT redistribute!
Thank you & Enjoy - P4NZ3RIV/CipherACE