So, quick thoughts on the Fidelio X2. Overall, I really like it. It's beautifully built, super comfortable and sounds great. It has a sort of fun sound signature, bit more bass and defined highs, mids slightly recessed over the 6XX. The upper reaches can seem to have a slightly artificial "sizzle" to it with some sibilant notes occasionally coming through but even so doesn't seem to create fatigue. I definitely prefer it's sound over the SHP9500 which is to be expected and it's in a completely different league in build quality.
BUT...for me, it's still no match for the 6XX when it comes to how I enjoy my music. There is some music that maybe suits it better but when I come back to that 6XX I get that amazing musicality and perfect balance that I like so much. The sharp edges are smoothed off just right amount. I am glad I have the X2 to compare as it really makes me appreciated the 6XX even more. Everything just sounds more natural with that perfect touch of warmth. Don't get me wrong I really like the X2 but the 6XX just seems like it was built for me. If you appreciate a wider soundstage then the X2 definitely has more to offer than 6XX in that regard where as for me the 6XX has that perfect amount of openness vs intimacy.
That being said, I didn't buy the X2 in an attempt to replace the 6XX, I bought it to try for gaming, with the added bonus of being able to have some fun with a bass heavy headphone when I felt like it. In that regard it seems to excel. For gaming the wider soundstage and impressive imaging seems to work nicely when listening for other players. I also think that with the drivers being set at an angle it means it's much easier to tell if something is directly in front of me vs behind me. I've found with my other headphones if a shot goes off directly behind or in front of me I sometimes have to turn slightly to make sure I haven't got confused. With the X2 the difference is much more obvious and I don't have to second guess myself, which is appreciated. It also just sounds good in games. Perhaps in some situations the additional bass may mask footsteps so will be something I keep in mind. Perhaps some EQ tweaking for a competitive game will be worthwhile. For single player immersion though these will be awesome I'm sure. Will definitely hang onto these things and add a boom pro.
Note these tests were all done on my uDSD which I can definitely hear is struggling to drive the 300ohm 6XX on certain songs (I actually see the odd clipping on some very sub-bass heavy songs) . So once I have the R2R 11 the 6XX may scale better and pull even further ahead of the X2. Conversely, this makes the X2 a much better portable option than the 6XX.
Anyway those are my thoughts and obviously with this being audio, YMMV . I'm also a relative newbie to the audiophile side of things so anything I say can be taken with a pinch of salt. Though I've always been quite the muso and once put a fair chunk of my life into my guitar so would hope I have a decent ear for this kind of stuff
