I download 3 times (flac, and mp3) for differents places and still cant get real quality.

My guess is that the GBA audio chip somehow limited the spectrum, but I know nothing

i think that too

Most GBA games don't go up to 320kbps as the chip more or less restricts it to less than half that but it's barely noticeable in most games but one game stood out to me for having the worse quality of music and that's Tetris Advance. That game gave me a headache because of the scratchy audio and I think that goes to show how little the company cared about it in Japan. Funny thing is that there's hacks that exist for the Final Fantasy GBA ports that replace the audio with that of the SNES games and it's obvious that the chip is not equipped for that as the quality suffered during the transition.

Most GBA games don't go up to 320kbps as the chip more or less restricts it to less than half that but it's barely noticeable in most games but one game stood out to me for having the worse quality of music and that's Tetris Advance. That game gave me a headache because of the scratchy audio and I think that goes to show how little the company cared about it in Japan. Funny thing is that there's hacks that exist for the Final Fantasy GBA ports that replace the audio with that of the SNES games and it's obvious that the chip is not equipped for that as the quality suffered during the transition.

If i'm not mistaken you can recreate the tracks with the midi file.