I had the brilliant idea of taking these apart this morning just to look around, parts seemed easy to replace if needed so I felt comfortable probably voiding my warranty given the price and convenience of repairing myself. I won’t need any repairs, but I have discovered that removing the sound damping on the inside of the earcups cleaned up the muddiness I was feeling with this headphone. It went from being my darkest to being up there with some of my most neutral. So I wondered about removing the walnut earcup next. This seems to mostly affect the bass and sub frequencies, making some songs sound like a small concert hall with the open back. I need to find a good system to compare back to back having the earcups on vs off, but it’s really intriguing that these headphones already EQ well, but now I can quickly mod them into a totally different experience practically on the fly. It’s 7 screws, off and back on again. I don’t recommend doing this if you are worried about the warranty, I only did this because I am not worried about the warranty. I have yet to have any issues with any of my 3 FiiO products, no this is not a paid promo. Curious to hear thoughts, I am sure I’m not the first to do this so I’m curious what others have tried, I’m already thinking different shapes or internal wall surfaces, even different wood for the earcups.