Comment by KozmoNau7

>"Well for me it came from running multiple copies of the same bass heavy tracks encoded in different formats through spectrum analysers. But I guess those lie?"

Of course it's going to look different in a spectrum analyzer, the whole point of lossy compression is to discard parts of the audio to save space.

You can't evaluate the quality of a lossy codec by looking at spectrograms. They're designed to fool human ears, not measurement software.