[syn_fx]

Did you download the 192s? In which case there is a possibility someone on the internet had a poor recording (say 128 or less) and then transformed into 192. It's an idiotic thing to do, but there are plenty of people who don't realise this does not make the SQ better.

This could explain the big "jump" from "192" to 320.

 

[Deftoned]

Sounds to me like it might have been an issue with the seal of the earphones that caused the drastical difference.

 

[krmathis]

To me there tend to be more of an audible difference between 192kbps and 320kbps than between 320kbps and lossless. But we do not have the same set of ears, so anyone else impression may be different than mine.

So not surprised you hear a difference between them, although I am surprised you think the 320kbps is lacking compared to the 192kbps one.

 

[MiG(TM)]

To me, the biggest difference is from using the latest LAME mp3 encoder. I use media monkey which lets you specify the encoder used.

I dread to think of the age of the MP3 encoder within iTunes. MP3 really has really come a long way since the early days. Some of my old MP3's sound horrific.

 

[Hentai11]

I A/Bed 320 to FLAC on my home setup if I spend an afternoon training my ear; I get some speed in the transients. It was a waste of an afternoon, though; the differences were barely audible on tracks I knew very, very well. I don't think I could do it cold, and I don't care to try.

192 to 320 I would hear instantly, though, especially on good phones.