Does anyone have an explanation (or link me to an article) as to how an IEM can reproduce lower end frequencies. I can't imagine those little 10mm drivers are putting out all that much. It seems that low-end presence is highly dependent on having a good seal which leads me to believe there's...

I need a new pair of best-bang-for-the-buck IEMs and I'm not really looking to spend much more than $50. I mainly use them while walking, bike riding, and using public transportation so decent isolation (not so much that I can't hear car horns, etc), little to no microphonics are highly...