Here’s something I found that puzzles me: I am usually operating under the assumption that saving music as M4A is “better” than saving it as MP3.
Well, I decided to convert some WAV music (taken directly from a disc I own) into a slightly smaller file. I used Audacity to export the WAV as (1) MP3 (both 256 and 320 kbps), and (2) as M4A (257 and 320 kbps). I then used audacity’s “plot spectrum” on the WAV and the four smaller files. The results are clear: the MP3 is definitely better than M4A (“better” in the sense that the plot shows higher frequency sounds in MP3 than in M4A (both, at 256 and 320 kbps). Unsurprisingly, the WAV is best, but not by much when compared to the 320 MP3.
This seems more objective than a hearing test. I got the same results in another musical piece I tried, so - at least when the source is WAV, I am perplexed. (I guess it’s a different story when the source is MP3 or M4A)
Can anybody un-perplex me?