>this audio tutorial will teach you how to hex edit. it talks about doing it for players but it's the same for team hdr files.
>this will give you the teams associated with each id number.
I haven't read your posts in its entirety yet, but sounds like you are on the right track from glancing at what you wrote. the dat files are the actual audio files, where the hdr files are sort of a place holder that tells the game to play the dat file. editing player audios is pretty straight forward, but i do remember there's something tricky about doing teams. i don't remember exactly what that is off the top of my head so you will have to experiment and see what happens.