I recently demoed some really high-end IEMs (top of the line Ultimate Ears, Noble, and Aurisonics) and they raised a lot of questions in my head. Here are some of those questions: 1) What parts to they use? That is, do different manufacturers use the same drivers and whatnot? If so, I'd like to create a list here. 2) Has anyone reverse engineered these high-end IEMs? These improvements seem pretty well-known and don't seem to be secrets (adding drivers for various freq ranges, adding extra holes for different frequencies, etc). 3) I'm wondering how hard it really is to manufacture/build an IEM those features 4) It seems like the width, length, and precision of the bass travels through makes a huge difference. These "ports" or whatever you call them is one design characteristic of IEMs that I'm interested in. I'm also truck by the huge difference in sound between, for example, the low-end model Noble makes versus the Kaiser 10. I wonder how much more the Kaiser 10 really is to manufacture than their lowest end model. The top-end model is ~$1500, while the low-end $300. Anyway, if you all know of any places which has reverse engineered and taken about some of these high end IEMs, then I think everyone would find their internal design interesting. Then it might be more apparent which physical features of the IEMs map to our perception/preferences. Would love to hear from any of you.