I have the DD EarbuDDs, and they sound great. I'd put them about on par with the Shure E2C's that I had, but with a lower bass extension. They do stay clear while playing some heavy bass, but I did get it to distort like hell one time playing a song that had a 17hz peak in it. While it was playing the 17hz note, there was seemingly no response about like 100hz and it seemed to fade in/out.
They are earphones though, I was not expecting nearly the amount of response out of these. Much less at such low frequencies.. Great earphones for the direct price.
I use these at the gym as well, so I do sweat quite a bit and they've held up very well as of now.