Quoted from Schwaggs:

You can put a "gain.txt" file in each event folder to manage the volume of each sound event separately.
If you have more than one sound in an event folder, you can put the sound file you wish to adjust in a sub-folder with any name (I use the name of the sound file) and put a gain file in the folder with the sound file to impact only that single file. The board will randomly play one of the files in the event folder, even if they are in a sub-folder.
If you want to impact all the sounds in an event folder, you can put a single gain file in that folder.
Is this what you were asking?

Quoted from aeonblack:

Install the board in your pin, update the firmware to the latest, either find an existing mix to use the sounds from or do your own rip from a factory ROM file to get all the sound files the game uses.
Step 1: Find a bunch of music you like, preferably in high quality .wav format
Step 2: Download Audacity (it's free!)
Step 3: Using Audacity, cut out the most awesome parts of those songs to use during gameplay. The speed of the game, the theme and the average ball time length will all affect what will work best here. Just use what you like.
Step 4: In Audacity, export those files into the "music" folder for the selected pin, replacing each individual track with your new track.
Step 5: Load it into the board, test it.
Step 6: Put a text file named "gain" into each specific folder you want to increase or decrease the volume of. Open "gain" text file and put a number from 1-20 in there (10 being no difference, 11-20 being plus, 1-9 being minus)
Step 7: Test again.
Step 8: Continue until sounds are balanced.
Step 9: ?????
Step 10: Enjoy your pin a lot more.
Optional Step 11: Replace callouts you have always hated with something better, or, using the technique Schwaggs mentioned, just add more so it's not as repetitive.