Hi guys, I had been a "normal" or "casual" listener most of my life, but now I have taken an interest in the "audiophile world". With that said, what are the things I should look for when trying to differentiate say, a 128 kbps MP3 file from the FLAC file it was originated from? Because currently I can't do that very effectively, when converting with Audacity using LAME 3.99.3. I use unamped Sennheiser HD 598s, which should have sufficient definition\clarity\resolution\transparency (I don't understand the difference between these terms) to allow for differentiation, do please do not turn this into a "your equipment is improper" debate.
If you really need more details (such as the songs used) I have another topic: http://www.head-fi.org/t/651413/are-my-ears-really-this-bad
P.S: I realize this has probably been asked around alot, but a with a quick search on Google I could not find it :P