These are incredible headphones. The design on these are perfect. It feels like they are molded right for inside of your ears. The clear casing allows you to see in, and look at the technology they are using. I didnt believe they could fit both of those drivers in that single little casing, but oh did they ever. The frequencies are crystal clear. They even sound great without a little headphone amp. I still use my little headphone amp anyways, It has always made a big difference in the past, so i am spoiled in that way. Great choice, and these are BUILT IN USA!!!! seems like the last product to do so. great choice!