Hey, I've checked your FLAC audio in Audacity using a spectrogram, and they are improper rips. 16-bit 48 KHz FLAC files are supposed to have a frequency range above 15-16 KHz, and these tracks cut off at that range with a lot of the songs. But not every song has this problem, just some. The frequency range should usually be above 19-20 KHz with no cutoffs, clipping, or noise issues.
On the other hand, a 128-192 kbps MP3 is usually up to 16 KHz, so that's fine. Please can someone remove the FLAC uploads because they are not "true FLAC". Or at least someone can try to re-rip them.