My new A2s came in today and here are my initial impressions. I don't know much about speakers so take my opinion with a grain of salt.
First off my new set has the Audioengine logo on the front but the original set didn't. I actually prefer the ones with the logo.
For my first test I connected them to my X-Fi and and tried a variety of songs. My impression was that I paid way too much for these speakers. I thought the mids sounded muddy, muddled, recessed, and overall things didn't sound very good.
I read that source can make a big difference so I was hopeful that connecting it to my Zero would sound a little better. To my surprise it sounded a lot better. It was like two different speaker systems. My feelings went from disappointment to very satisfied. They're not the most amazing speakers I've ever heard but they are the best I've ever heard in this size. I'm very happy with them.
There is a slightly nasal, "cupped hands" sound to them, too. There is also a slight hollowness that gives it a bit of a "boxy" sound.
I though the same thing about the A2s with my X-Fi but when I moved it to my Zero it seemed like most of that went away.