Quoted from the site: www.zmfheadphones.com
"The ZMF is an incredible all around headphone made to handle all frequency ranges effortlessly. Whether it’s music, sound mixing, or field recording, you’ve come to the right place.
The ZMF was created with the Hifiman He-500 in mind. I had searched long and hard to find a headphone that I simply couldn’t be without, something that most headphone lover’s don’t feel after owning a set for a while. It’s easy to buy and sell pairs looking for the “next best thing.” That was me a couple years ago. Then I got the He-500. It does everything incredibly well and suits most musical styles with ease. BUT, it’s expensive, and it’s an open headphone, not right for all applications. Hence my search for a closed partner in crime. I then modified a pair of the Fostex t50rp headphones for my brother as a present for his birthday. They were the first set I modified, and little would I know it would send me on a journey to perfect the modification. A couple years later, after modifying through almost fifty iterations of the ZMF, I began to sell the head-phone just to make my money back. After enthusiastic response from listeners I decided it was time to unleash the ZMF to the public, and here it is. The ZMF gives you the best, most liquid, enjoyable sound, at a better price than the rest of the market. You won’t be disappointed.
The ZMF’s are made for each individual customer in our workshop in Chicago – Illinois, USA. Every set is tailored to have the specific options for each ZMF user. With more customizable options aesthetically and sonically than any other t50rp out there, you can, and will get what you want."