Originally Posted by ssamadhi97

MP3s have no inherent resolution, and whether the input or output file is 16 or 24 bit doesn't matter, mostly thanks to the quantization noise introduced by the encoder.

Additionally, both the ear model and the limitations that make mp3 so horribly inefficient at high-frequency content above 16kHz are just the same, no matter whether you're encoding a 44.1kHz or a 48kHz source.

So all in all, the sa "fingerprint" of a 48kHz "24bit" mp3 looks just like that of a 44.1kHz "16bit" mp3, only with slightly shorter blocks and "more nothing going on" at the top of the spectrum.