I moved this from the other tutorial forum per request by a higher power.

If you're OCD like me and have to have everything just right, MP3 Gain evens out the background music so that no piece of music is louder than the other. Basically, you take all of your background music and add it all to the list by selecting Add Files. Check one of the songs that sounded the best whenever you fought in MUGEN and use that as a base number. Then, change the Target "Normal" Volume to that number. At the end, the numbers will all be different most likely, but they will generally be in the same area. My "Normal" number was 90.

MP3 Gain is free. I didn't feel this belonged in the video recording tutorial area, but it definitely helps there too. This is mostly to keep bgm you downloaded from blaring out or being too quiet.

Download the file that looks like this: mp3gain-win-full-1_2_5.zip

If you need any help with this, let me know. It's a fairly simple fix to an issue that some people may not have a problem with. This is just being posted for convenience. Surely I'm not the only one who hates uneven background music.