The high frequency roll-off was pretty evident to me for some reason. Maybe I'm more sensitive to the treble? I was using the M-100 too, which has the highest octave rolled off according to Tyll.
That's no excuse. I used the V-MODA M-100 straight out of my MacBook for all of the tests but the golden ears' timbre frequency picker. It was too hard to do stuff with the M-100 on that test and it was pretty straightforward with the Alpha Dog.
See below. XD
I thought the MP3 artifacts were fairly easy to identify. It's mostly the treble region that gave it away for me with the weird robotic-like sounds.
LOL the EDM one. The bass colouration was so obvious it took me less than a second to identify them most of the time.