.add file extension

[KingVariares]

Hello everyone, so I have been fiddling around with a game I would like to mod, I so far have learned this, when you extract the .iso the main file type you will see is .add. Now when I look this file up theres not many resources or results to help conquering this file. The file is a compressed composition of many other files, (the easy ones to work with), such as .vag (audio), .gmo (models), .gim (images) (I think I said that correctly. But the way I have been able to extract the files is using HxD hex editor, you can extract the .add files by changing the .add extension and adding a .rar. But when you extract it, only one file comes out. So what I do is go through the file with HxD and erase each file and the encoding in between to get each file with individual extractions. I then tried to recompress those files into an .add file that was easier to extract and replace it in the .iso. But when I did that the sounds that were in the original .add file were all gone (voicelines). I think the issue is the fact that I renamed the file to .rar, so the file type has changed and thus is not being detected by the emulator or .iso anymore. If anyone knows anything about these .add PSP iso files, or could create a tool that decrypts the files easier that would be much appreciated. (I don't really expected a lot if any responses to this but it is worth a shot)