>>1775298And so, while I already had the audio files extracted, I thought I'd examine them a bit more, since I was intrigued by how big of a difference just the audio quality made. Turns out that they're both pretty low quality audio, since the frequency range abruptly ends at a point instead of naturally getting quieter the higher the frequencies go. In the lower quality version, this point is at around 10 kHz, and in the higher quality version, the point is at around 16 kHz. However, at the loudest peaks of the song, there is some extra stuff in those high frequencies, and I tried using a low-pass filter to get rid of them. When I did, the distortion was more or less gone without any extra sonic information being lost.
Therefore, if a brilliant masterpiece MMD video is being ruined by clipping issues, it's salvageable by extracting the audio, applying a LPF to it at a certain frequency, and then putting the video back together using the modified audio, if it's worth it.
I'm still going to find out why some videos sound good already when I stream them in low quality on trollvids later because I'm intrigued by this.