Hello everyone,
During the black Friday I bought the Fidelio X2HR. I read online that, before using new headphones, you have to do a "burn-in" for several hours. I connected the Fidelio to my DAC/AMP (a Fiio K9) and I left them there for several hours while a mix of music and pink noise was playing. However, since I'm used to my old 150 ohm headphones (superlux hd681 evo), I putted the volume almost at max level (low gain), to be precise the knob was a little over the 3 o'clock position. Now I'm using my new Fidelio but the details, the clarity and especially the highs seem worse than my old headphones, but maybe it's just my perception I can't tell for sure. I noticed that my Fidelio sounds better at lower volumes, the bass don't overshadow other instruments, however I still get the impression that they don't sound as good as my old ones. Will the sound of the Fidelio improve over time?is it just my impression and I just have to get use to the new headphones? Or should I return the Fidelio back?
I highly suspect the headphones are fine and your brain is just getting used to the different sound. I thought my HD6XX were crap (edit; actually, just very 'samey' compared to my other cans at the time) initially, now they are like nothing I have ever experienced anywhere else; literal velvet sound.
My X2's have decent bass but it's not in 'blow me away' territory, just a bit of a bump. As others have remarked my treble is also quite grainy compared to my other cans and that may or may not be for you; once I heard it I could never not hear it again.
I've never tried the Superlux so I can't compare to those.