How to check MP3 quality? 2007-05-06 13:00:53 (Maybe it's an old question, so if it is, maybe forward me to another discussion topic...)I read here about many tests between various endcoders, starting from a PCM file to the encoded one. Then some ratings are exposed. But i can't understand how you check the differences between original\encoded files. I mean: i should listen both? And if i have no HI-FI equipment (only MID-FI)?I usually check the result of the encoding with a spectrum analyzer, and here i saw the impossible... referring to the mp3s that was not encoded by me. You know, LAME applies various lowpass filters: more the cut frequency is high, more the quality is high. A 128kbps has a Cf of 16KHZ, a 192 one has about 18KHz Cf.The question is: is good to base on spectrum data to validate the quality of a LAME enc mp3? I saw for example that a 192kbps mp3 has about the same cut-off of a 240kbps VBR. In this case there are differences between them (except for filesize). And i also found the parameter -k (no filtering, but seems to work only for 3.90.3) and the output spectrum is amazing (near to full scale!) but there are here distorsions??And in LAME 3.97, a 320kbps has an horrible frequency response (i still can see a net "cut" on 16KHz)!Some explanations are very appreciated! Thanks!