How do I PERMANENTLY add gain to front center audio track only?

Question

After YEARS of not being able to find an answer as to why certain videos had background music drowning out voices, I finally got an answer, kinda. For reasons that I have long since given up on solving, audio that's more than 2 channels is not downmixed properly, across clean installs of every version since 10.04. Simple fix was to install Pulseaudio control panel, and boost Front Center by about 30%. BUT! I have to do that EVERY TIME. It's really annoying. I'm not that good with editing code and all that, but even if it constantly resets the volume to 100% (and 130% for front) every time, is there a way to make that ratio the default? Even if I make a playlist, it sometimes resets between episodes, sometimes it does not. Sometimes if I close VLC and restart the same video, the change in front volume will still be there, sometimes it won't. So I know there is some ability to retain the setting in there somewhere. Please help, thanks.