Re: Does mp3 have more bass information than m4a?
Reply #3 –
This isn't a correct way to compare lossy codecs since their ultimate goal is to press as much bits as possible out of the song while keeping the necessary information to fool the ears&brain into not hearing any difference from the original under normal circumstances (like, not listening to isolated channel differences, some extreme EQ settings, etc).
They might use quite different methods to do this but this alone doesn't mean that one is better than the other.
Regrading the bass, if you pick a quality setting when the codec should be transparent, it follows that the bass is perceived the same.
mp3 cbr 320kbps should be transparent and it is already waste of space, there's no point using CBR 320 if you can use V0 or even V2 (V2 is transparent to most people AFAIK, and if it's not, it's probably a "killer sample" of some sort).
AAC at even higher bitrates is, in turn, even more silly.
If you can hear a difference with the source on any of these, it probably means you're doing something wrong with the conversion or playback... because in both cases it should normally be impossible to hear difference.