I just did a spectral anaylsis and mp3 seems to be closer to the flac and wav of a song that i ripped. I always thought that aac was better was mp3, or is this just at lower bitrates?

Do you listen to your audio files or do you look at them?

This subject (the use of spectral analysis for the evaluation of audio quality) has been discussed in great length on this forum, feel free to use the forum search function to do some research.

In short, spectral analysis generally doesn't tell you much about perceived audio quality.

Even so, a 320 kbps LAME MP3 file could very well sound better than an AAC file unless the AAC file, especially if the AAC file is a lower bitrate.

Nope. Too many factors affect quality: Bitrate, encoder used, encoding options, etc. You can only decide after doing abx tests.

But in theory the aac format has more potential than mp3 at similar bitrates. A 320kbps mp3 is not perfect or efficient either. You might not hear any difference using a lower bitrate, thats why you should do abx tests to determine what quality is best for you.

like one of gurus in this foorum have tested at 80 kbps, the Nero HE AAC
the spectrum is at CD Quality WAVe, wich mean have full spectrum, but the real quality was not so good, I learned, the spectrum is not most important things at all, it is only one of many factor on wich depends compressed audio quality